Load port

CROSS-REFERENCE TO RELATED APPLICATIONS

0001The instant application is a continuation-in-part of U.S. patent application Ser. No. 11/630,123, filed Dec. 19, 2006, now pending, and incorporated by reference herein.

BACKGROUND OF THE INVENTION

00021. Field of the Invention

0003The present invention relates to a load port which is provided for a wafer processing apparatus for transferring various kinds of substrates (which will be referred to as “wafers” hereafter) such as silicon wafers, and which has a function of detaching/mounting a lid member (which will be referred to as “carrier door” hereafter) of a wafer storage container (which will be referred to as “wafer carrier” hereafter) for storing wafers at a predetermined pitch.

00042. Related Art

0005Known examples of such kinds of conventional load ports include an arrangement that includes a load port door which has a function of engaging with a carrier door, and a load port door opening/closing mechanism that allows the load port door to be opened and closed, and that has a function of replacing (which will be referred to as “purging” hereafter) the atmosphere of a wafer carrier while maintaining the state in which the carrier door is opened.

0006Such a load port is disclosed in Japanese Unexamined Patent Application Publication No. 2003-45933 (which will be referred to as “Patent Document 1” hereafter) with reference to <figref idref="DRAWINGS">FIGS. 1 to 3</figref>. The load port disclosed in Patent Document 1 includes an upper wall face, a lower wall face, and an EFEM (Equipment Front End Module) door, etc., which serve as partitions between a predetermined space adjacent to the open face formed in the carrier door, and a processing space provided within a wafer processing apparatus, and has a function of purging the atmosphere of the wafer carrier through the aforementioned predetermined space.

0007However, with the load port disclosed in Patent Document 1, N₂gas or the like used for purging the atmosphere of the wafer carrier (which will be referred to as “purge gas” hereafter) is supplied from the side obliquely above the open face of the wafer carrier.

0008In some cases, this leads to a problem of insufficient supply of the purge gas to the spaces between the adjacent wafers. Now, let us consider an arrangement in which purge gas is supplied with an increased flow amount. In some cases, even such an arrangement has a difficulty in sufficiently purging the atmosphere, and could lead to higher costs for purging the atmosphere.

0009Furthermore, the load port disclosed in Patent Document 1 includes the EFEM mechanism that allows the EFEM door to be opened and closed. This leads to a structure in which the EFEM mechanism protrudes toward the processing space provided within the wafer processing apparatus. This results in the problem that such a structure does not conform to the so-called SEMI standard, which specifies that any protrusion should be formed with a length of 100 mm or less from the wall face of a wafer processing apparatus.

SUMMARY OF THE INVENTION

0010It is an object of the present invention to provide a load port that enables the purge to be performed with high precision in a short period of time.

0011The present invention relates to a load port having a function of detachably mounting a lid member to a container opening of a wafer storage container for storing wafers therewithin at predetermined intervals by engaging the lid member with a door member of a door opening portion of a chamber into which each of the wafers is to be transferred, comprising: a nozzle unit having nozzle outlets for generating an outflow and/or an inflow of a gas, which is used for replacing the atmosphere of the wafer storage container, in a direction approximately parallel to the spaces between the adjacent wafers stored in the wafer storage container; and a driving unit for extending the nozzle unit to the door opening portion.

0012In the present invention, the nozzle unit may include a first nozzle unit for generating an outflow of the gas, and a second nozzle unit for generating an inflow of the gas. Also, the first nozzle unit and the second nozzle unit may be disposed approximately symmetrically with respect to the center line of the wafer storage container defined along the feeding direction along which the wafer is to be transferred to the chamber.

0013In the present invention, the nozzle outlets may be formed at positions that correspond to the spaces between the adjacent wafers.

0014In the present invention, the nozzle outlets may be formed at predetermined intervals along the vertical direction in which the wafers are stored within the wafer storage container.

0015In the present invention, the multiple nozzle outlets may be formed along a direction approximately oblique to the vertical direction.

0016In the present invention, the nozzle unit may be formed with a thickness twice or more the diameter of the nozzle outlets.

0017In the present invention, the nozzle unit may be an arc-shaped member provided such that it can be turned with a portion near a side end of the door opening portion serving as a turning axis, and can be stored at a position outside of the course of the wafer which is transferred from the wafer storage container to the chamber.

0018In the present invention, the driving unit may turn the nozzle unit with a portion near a side end of the door opening portion serving as a turning axis, thereby extending the nozzle unit from the side face of the door opening portion to the door opening portion.

0019In the present invention, the nozzle unit may be formed of a thin plate-shaped member which can be stored within a storage portion for storing the lid member, and in which the nozzle outlets have been formed over approximately the entire region such that they correspond to the spaces between the wafers.

0020In the present invention, the driving unit may extend the nozzle unit from a position near the lower end of the door opening portion to the door opening portion.

0021In the present invention, the nozzle unit may be formed of a tube-shaped member which can be stored within a storage portion for storing the lid member.

0022In the present invention, the driving unit may extend the nozzle unit from a position near the lower end of the door opening portion to the door opening portion.

0023In the present invention, the nozzle unit may be formed of a thin plate-shaped member in which the nozzle outlets have been formed over approximately the entire region such that they correspond to the spaces between the wafers, and which can be turned with a portion near an end of the upper portion of the door opening portion serving as a turning axis, thereby enabling the nozzle unit to be stored around the upper end of the door opening portion.

0024In the present invention, the driving unit may turn the nozzle unit with an end of the upper portion of the door opening portion serving as a turning axis, thereby extending the nozzle unit from a position near the upper end of the door opening portion to the door opening portion.

0025In the present invention, the nozzle unit may be formed of a tube-shaped member that can be turned with an end of the upper portion of the door opening portion serving as a turning axis, thereby allowing the nozzle unit to be stored around the upper end of the door opening portion.

0026In the present invention, the driving unit may turn the nozzle unit with an end of the upper portion of the door opening portion serving as a turning axis, thereby extending the nozzle unit from a position near the upper end of the door opening portion to the door opening portion.

0027In the present invention, the load port may further comprise an auxiliary nozzle unit which is provided around the upper end of the door opening portion, and which generates a gas flow in the shape of a slender planar curtain.

0028In the present invention, the load port may further comprise an airtight space forming unit which can be connected to the opening of the container in an airtight manner, thereby forming an airtight space that communicates with the interior space of the container.

0029In the present invention, the airtight space forming unit may comprise: the storage portion; an upper-portion cover member provided such that it faces the upper face of the storage portion; and an inner-face cover member which can be stored within the storage portion in a shape that follows the inner face of the storage portion, and which can be extended/retracted from/to the storage portion.

0030In the present invention, the load port may further comprise a flow control unit for switching the flow of the gas, which is generated by the nozzle unit, at a predetermined timing.

0031In the present invention, the flow control unit may comprise: a detection unit for detecting the gas concentration of the atmosphere of the wafer storage container; a switching unit for switching the flow of the gas generated by the nozzle unit; and a switching control unit for controlling the switching unit such that the gas concentration detected by the detection unit falls within a predetermined range, which is an indicator that indicates the degree of the replacement of the atmosphere.

0032In the present invention, the load port may further comprise an exhaust adjustment unit for adjusting the exhaust amount, which is discharged outside, such that the pressure of the airtight space is higher than the outside pressure while maintaining the state in which the atmosphere of the wafer storage container has been replaced using the nozzle unit.

0033In the present invention, the load port may further comprise a replacement control unit that replaces the atmosphere of the wafer storage container using the nozzle unit with the inner-face cover member being stored within the storage portion after the atmosphere of the wafer storage container has been replaced through the airtight space.

0034In the present invention, the nozzle unit may be formed of a thin plate-shaped member provided at a position outside of the course of the wafer which is transferred from the wafer storage container to the chamber. Also, an arrangement may be made in which the nozzle unit can be stored within a storage portion for storing the lid member.

0035In the present invention, the driving unit may extend the nozzle unit from a position around the lower end of the door opening portion to the door opening portion when the inner-face cover member, which can be extended/retracted from/to the storage portion, is extended from the storage portion.

0036In the present invention, the load port may further comprise a holding unit that allows the nozzle unit, which has been extended to the door opening portion by the driving unit, to be held at its extended position.

0037In the present invention, an arrangement may be made in which the nozzle unit can be stored within a storage portion for storing the lid member. Also, the nozzle outlets may be formed over approximately the entire region of the nozzle unit such that they correspond to the spaces between the wafers. Also, the nozzle unit may include a first thin plate-shaped member disposed at a position outside of the course of the wafer which is transferred from the wafer storage container to the chamber, and a second thin plate-shaped member disposed around the center of the door opening portion.

0038In the present invention, the driving unit may provide a function of extending the first thin plate-shaped member and the second thin plate-shaped member independently of one another from positions around the lower end of the door opening portion to the door opening portion.

0039In the present invention, the driving unit may provide a function of retracting the second thin plate-shaped member from the door opening portion while holding the first thin plate-shaped member at its extended position after the first thin plate-shaped member and the second thin plate-shaped member have been extended to the door opening portion.

0040In addition, the present invention provides a load port that is disposed between a wafer storage container having a lid member closing an aperture thereof and an inner wall of a curved surface so as to store wafers and a receiving room, into which the wafers inside the wafer storage container are conveyed. The load port includes an intermediate room, a gas supply plate configured like a plate, a partition, a gas outlet, and a driving unit. The intermediate room is disposed between the wafer storage container and the receiving room. The partition is configured like a plate to separate a partial region between the intermediate room and the wafer storage container. The gas outlet is configured to supply a replacement gas into the intermediate room. The driving unit is configured to: evacuate the lid member from the aperture of the wafer storage container into the intermediate room; position the gas supply plate in a region facing the aperture of the wafer storage container on one side with respect to a center line along a direction in which the wafers are conveyed; and position the partition in a region facing the aperture of the wafer storage container on another side opposite to the one side with respect to the center line, when the load port performs gas replacement. The gas supply plate includes a plurality of outlet nozzles configured to eject the replacement gas, each being arranged in agreement with a gap between adjacent wafers in a direction in which the wafers are layered. The plurality of outlet nozzles is formed in an entirety of the gas supply plate. The gas supply plate and the gas outlet are configured to supply the replacement gas such that a pressure of the receiving room is regulated to be lower than a pressure of the intermediate room. The gas inside the wafer storage container moves in a direction along the inside wall of the curved surface due to the replacement gas ejected through the plurality of outlet nozzles, subsequently circulating in a substantially entire region inside the wafer storage container since a pressure of the wafer storage container becomes higher than a pressure of a region adjacent to the partition. A part of the gas circulating inside the wafer storage container moves from inside the wafer storage container into the intermediate room through a gap between the gas supply plate and the partition due to a pressure difference between the wafer storage container and the intermediate room.

0041It may be that: the partition includes a plurality of inlet nozzles, each being arranged in agreement with the gap between the adjacent wafers in the direction in which the wafers are layered; the plurality of inlet nozzles is formed in an entirety of the partition; and a part of the gas circulating inside the wafer storage container moves from inside the wafer storage container into the intermediate room through the plurality of inlet nozzles in addition to the gap between the gas supply plate and the partition due to the pressure difference between the wafer storage container and the intermediate room.

0042Furthermore, it may be that the load port further includes a side wall and a side cover member. The side cover member has a side face arranged opposite to the side wall when the load port performs the gas replacement. The side wall and the side cover member form the intermediate room. The intermediate room includes a flow passage formed between the side wall and the side face of the side cover member. The flow passage causes the receiving room to fluidly communicate with the intermediate room and applies fluid resistance to a gas moving from the receiving room into the intermediate room.

0043According to the present invention, the nozzle unit generates an outflow and/or an inflow of a gas from the openings of the nozzle unit toward the spaces between wafers so as to replace the atmosphere of the wafer storage container. Furthermore, the nozzle unit can be extended to the door opening portion. Such an arrangement provides a gas flow toward the spaces between the wafers with high efficiency, thereby reducing the period of time necessary to replace the atmosphere of the wafer storage container. At the same time, this provides high-precision replacement of the atmosphere.

0044In addition, the present invention provides advantages below.

0045Each of the plurality of outlet nozzles is arranged in agreement with the gap between the adjacent wafers in the direction in which the wafers are layered. Furthermore, the plurality of outlet nozzles is formed in the entirety of the gas supply plate. Accordingly, it is possible to decrease a velocity of the replacement gas even if a considerable amount of the replacement gas is ejected between the wafers at a time, allowing the replacement gas to move in a laminar flow. As a result, it is possible to increase the efficiency of removing moisture and foreign materials (particles) in the vicinity of a surface of a wafer.

0046The present invention supplies the replacement gas from the region facing the aperture of the wafer storage container and employs the inner wall of the curved surface of the wafer storage container and the partition to allow the replacement gas to circulate in the substantially entirety of the wafer storage container. Accordingly, a centrifugal force occurs, which causes the foreign materials to move from an inner periphery to an outer periphery of a wafer. In addition, it is possible to cause the foreign materials to move from the wafer storage container into the intermediate room along with a gas, by utilizing the pressure difference between the wafer storage container and the intermediate room. In this manner, it is possible to remove the foreign materials from the wafer storage container.

0047It is possible for the present invention to cause a gas that moves along the partition, which is a part of the gas circulating inside the wafer storage container, to move from the wafer storage container into the intermediate room through the plurality of inlet nozzles. Accordingly, it is possible to increase the efficiency associated with the replacement of gasses.

0048Since the present invention includes the passage that applies the fluid resistance to the gas moving from the receiving room into the intermediate room, it is possible to increase the air tightness of the intermediate room and provide easier pressure control of the intermediate room.

BRIEF DESCRIPTION OF THE DRAWINGS

0049<figref idref="DRAWINGS">FIG. 1</figref> is a perspective view which shows a load port mounting a wafer carrier in a purge step, according to an embodiment 1 of the present invention.

0050<figref idref="DRAWINGS">FIG. 2</figref> is a side view which shows the load port mounting the wafer carrier in the purge step, according to the embodiment 1 of the present invention.

0051<figref idref="DRAWINGS">FIG. 3</figref> is a side view which shows the load port with the wafer carrier mounted after the purge step, according to the embodiment 1 of the present invention.

0052<figref idref="DRAWINGS">FIG. 4</figref> is a cross-sectional view which shows the load port with the wafer carrier mounted in the purge step, according to the embodiment 1 of the present invention.

0053<figref idref="DRAWINGS">FIG. 5A</figref> is a diagram which shows a state in which a first nozzle unit has been extended to a door opening portion.

0054<figref idref="DRAWINGS">FIG. 5B</figref> is a diagram which shows a state in which the first nozzle unit has been retracted from the door opening portion.

0055<figref idref="DRAWINGS">FIG. 6A</figref> is a diagram which shows a state in which the first nozzle unit has been extended to the door opening portion such that it faces the wafers stored within the wafer carrier.

0056<figref idref="DRAWINGS">FIG. 6B</figref> is a cross-sectional view of the first nozzle unit.

0057<figref idref="DRAWINGS">FIG. 7</figref> is a block diagram which shows the load port according to the first embodiment of the present invention.

0058<figref idref="DRAWINGS">FIG. 8</figref> is a flowchart which shows the operation of the load port according to the first embodiment of the present invention.

0059<figref idref="DRAWINGS">FIG. 9</figref> is a perspective view which shows a load port with the wafer carrier mounted in a purge step, according to the second embodiment of the present invention.

0060<figref idref="DRAWINGS">FIG. 10</figref> is a perspective view which shows a load port with the wafer carrier mounted in a purge step, according to the third embodiment of the present invention.

0061<figref idref="DRAWINGS">FIG. 11</figref> is a perspective view which shows a load port with the wafer carrier mounted in a purge step, according to the fourth embodiment of the present invention.

0062<figref idref="DRAWINGS">FIG. 12</figref> is a side view which shows a load port with the wafer carrier mounted in a purge step, according to the fifth embodiment of the present invention.

0063<figref idref="DRAWINGS">FIG. 13</figref> is a side view which shows a nozzle unit of the load port, which has been held at its extended position, according to the fifth embodiment of the present invention.

0064<figref idref="DRAWINGS">FIG. 14A</figref> is a side view which shows a load port with the wafer carrier mounted in a purge step, according to the sixth embodiment of the present invention.

0065<figref idref="DRAWINGS">FIG. 14B</figref> is a side view which shows a state in which a first nozzle unit and a second nozzle unit of the load port according to the sixth embodiment of the present invention are held by their extended positions, and a third nozzle unit and a fourth nozzle unit thereof have been retracted from the door opening portion.

0066<figref idref="DRAWINGS">FIG. 15</figref> is a plan sectional view showing a load port and a wafer carrier according to a seventh embodiment.

0067<figref idref="DRAWINGS">FIG. 16</figref> is an enlarged view (sectional view along line <b>16</b>-<b>16</b> of <figref idref="DRAWINGS">FIG. 15</figref>) showing a gas supply plate and a partition according to the seventh embodiment when viewed from nozzles.

0068<figref idref="DRAWINGS">FIG. 17</figref> is a side sectional view showing the load port and the wafer carrier according to the seventh embodiment.

0069<figref idref="DRAWINGS">FIG. 18</figref> is a plan sectional view showing a load port and a wafer carrier according to an eighth embodiment (corresponding to <figref idref="DRAWINGS">FIG. 15</figref>).

0070<figref idref="DRAWINGS">FIG. 19</figref> is a perspective view showing a load port according to a ninth embodiment.

0071<figref idref="DRAWINGS">FIG. 20</figref> is a plan sectional view (sectional view along line <b>20</b>-<b>20</b> of <figref idref="DRAWINGS">FIG. 19</figref>) showing the load port and a wafer carrier according to the ninth embodiment.

0072<figref idref="DRAWINGS">FIG. 21</figref> is an enlarged view (inside a long dashed double-short dotted line of <figref idref="DRAWINGS">FIG. 20</figref>) showing the load port according to the ninth embodiment.

0073<figref idref="DRAWINGS">FIG. 22</figref> is a perspective view showing a load port according to a tenth embodiment.

0074<figref idref="DRAWINGS">FIG. 23</figref> is a plan sectional view (sectional view along line <b>23</b>-<b>23</b> of <figref idref="DRAWINGS">FIG. 22</figref>) showing a part of the load port according to the tenth embodiment.

DETAILED DESCRIPTION OF THE INVENTION

0075A further description will be given of embodiments of the present invention with reference to the drawings.

First Embodiment

0076A load port <b>100</b> includes a wall face <b>201</b> or the like having a door opening portion <b>202</b> on which an unshown door member (which will be referred to as “load port door” hereafter) is detachably mounted. The load port <b>100</b> is installed on the wall face of an unshown wafer processing apparatus for performing predetermined processing for wafers <b>1</b>.

0077As shown in <figref idref="DRAWINGS">FIG. 1</figref>, a wafer carrier <b>10</b> is a container for storing the wafers <b>1</b> therewithin at a predetermined pitch (at a pitch of around 10 mm). The wafer carrier <b>10</b> includes a carrier shell <b>11</b>, and a carrier door <b>16</b> (see <figref idref="DRAWINGS">FIG. 3</figref>) or the like for sealing the container opening <b>12</b> of the carrier shell <b>11</b>. Note that known examples of such carriers include an FOUP (Front Opening Unified Pod) and an FOSB (Front Opening Shipping Box).

0078The carrier shell <b>11</b> includes a curved inner wall <b>11</b><i>a </i>(see <figref idref="DRAWINGS">FIG. 4</figref>) formed at a position opposite to the container opening <b>12</b>. Furthermore, the carrier shell <b>11</b> includes a robot flange <b>13</b> on the upper portion thereof as shown in <figref idref="DRAWINGS">FIG. 2</figref>, which allows an unshown automatic transfer apparatus to hold the carrier shell <b>11</b>. Furthermore, the carrier shell <b>11</b> includes V-shaped groove portions <b>15</b> in which V-shaped grooves have been formed.

0079The load port <b>100</b> is an apparatus having a function of detaching/mounting the carrier door <b>16</b> with the carrier door <b>16</b> for the container opening <b>12</b> of the wafer carrier <b>10</b> being engaged with the load port door of the door opening portion <b>202</b> of the load port <b>100</b>. The load port <b>100</b> includes: a mounting base <b>101</b> for mounting the wafer carrier <b>10</b> transferred from the automatic transfer apparatus; a moving base <b>102</b> which is movably provided on the mounting base <b>101</b>; a load port door opening/closing mechanism <b>170</b> (see <figref idref="DRAWINGS">FIG. 7</figref>) which is provided within a storage portion <b>121</b> described later, and which allows the load port door engaged with the carrier door <b>16</b> to be opened/closed; a nozzle unit <b>110</b> (see <figref idref="DRAWINGS">FIG. 1</figref>); an airtight space forming unit <b>120</b>; an exhaust adjustment unit <b>130</b>; an auxiliary nozzle unit <b>140</b>; etc. The moving base <b>102</b> includes kinematic pins <b>103</b> or the like on the upper portion for positioning the wafer carrier <b>10</b>. The kinematic pins <b>103</b> are engaged with the aforementioned V-shaped groove portions <b>15</b> provided to the bottom face of the carrier shell <b>11</b>.

0080The nozzle unit <b>110</b> includes a first nozzle unit <b>110</b>-<b>1</b> for generating an outflow (or inflow) of the purge gas, and a second nozzle unit <b>110</b>-<b>2</b> for generating an inflow (or outflow) of the purge gas, which allows the atmosphere of the wafer carrier <b>10</b> to be purged.

0081Note that the first nozzle unit <b>110</b>-<b>1</b> and the second nozzle unit <b>110</b>-<b>2</b> have approximately the same structure and functions, and accordingly, a description will be given below mainly regarding the first nozzle unit <b>110</b>-<b>1</b>.

0082The first nozzle unit <b>110</b>-<b>1</b> has nozzle outlets <b>111</b> (see <figref idref="DRAWINGS">FIG. 6</figref>) or the like for generating an outflow of the purge gas in a direction approximately parallel to the spaces between the adjacent wafers <b>1</b> stored in the wafer carrier <b>10</b> as shown in <figref idref="DRAWINGS">FIG. 2</figref>.

0083The first nozzle unit <b>101</b>-<b>1</b> is a member having an arc cross-sectional shape provided such that it can be turned with a portion near the side end of the door opening portion <b>202</b> serving as the turning axis, thereby allowing the first nozzle unit <b>110</b>-<b>1</b> to be extended and retracted with respect to the door opening portion <b>202</b> by the nozzle driving motor <b>166</b> or the like (see <figref idref="DRAWINGS">FIG. 7</figref>).

0084When the first nozzle unit <b>110</b>-<b>1</b> is retracted from the door opening portion <b>202</b>, the first nozzle unit <b>110</b>-<b>1</b> is stored within a clean space which is defined by the wall face <b>201</b> and an outer wall face <b>203</b> connected to the wall face <b>201</b>, and which communicates with an airtight space B described later. Such an arrangement prevents the first nozzle unit <b>110</b>-<b>1</b> from being contaminated.

0085On the other hand, when the first nozzle unit <b>110</b>-<b>1</b> is extended to the door opening portion <b>202</b>, the first nozzle unit <b>110</b>-<b>1</b> is located outside of the course H of the outer edge of the wafer <b>1</b> which is transferred from the wafer carrier <b>10</b> to the wafer processing apparatus.

0086With such an arrangement, each wafer <b>1</b> can be transferred to a processing space within the wafer processing apparatus for executing predetermined processing with a side-face cover member <b>122</b> described later being stored in the storage portion <b>121</b>, while maintaining the state in which the atmosphere in the wafer carrier <b>10</b> is purged by the first nozzle unit <b>110</b>-<b>1</b> extended to the door opening portion <b>202</b>. Such an arrangement improves the operating efficiency.

0087On the other hand, the first nozzle unit <b>110</b>-<b>1</b> and the second nozzle unit <b>110</b>-<b>2</b> are disposed approximately symmetrically with respect to the center line G of the wafer carrier <b>10</b> defined along the feeding direction along which each wafer <b>1</b> is to be transferred to the processing space in the wafer processing apparatus. Accordingly, the purge gas flowing out from the nozzle outlets <b>111</b> of the first nozzle unit <b>110</b>-<b>1</b> in a direction approximately parallel to the spaces A, between the adjacent wafers <b>1</b> stored in the wafer carrier <b>10</b>, is diffused along the inner wall <b>11</b><i>a </i>formed in the carrier shell <b>11</b> in the shape of a curved face, up to around the container opening <b>12</b>. Subsequently, the purge gas enters the second nozzle unit <b>110</b>-<b>2</b> disposed approximately symmetrical to the first nozzle unit <b>110</b>-<b>1</b> with respect to the center line G.

0088The first nozzle unit <b>110</b>-<b>1</b> includes: a pipe <b>112</b> which also serves as a rotational shaft that allows the first nozzle unit <b>110</b>-<b>1</b> to be turned; a support member <b>113</b> for supporting the rotational shaft through a bearing; a crank-shaped arm member <b>114</b> provided such that the pipe <b>12</b> passes through the arm member <b>114</b>; etc., at the lower portion of the first nozzle unit <b>110</b>-<b>1</b>, as shown in <figref idref="DRAWINGS">FIGS. 2</figref>, <b>3</b>, and <b>5</b>. <figref idref="DRAWINGS">FIG. 5A</figref> is a diagram which shows the state in which the first nozzle unit <b>110</b>-<b>1</b> has been extended to the door opening portion <b>202</b>. On the other hand, <figref idref="DRAWINGS">FIG. 5B</figref> is a diagram which shows the state in which the first nozzle unit <b>110</b>-<b>1</b> has been retracted from the door opening portion <b>202</b>. Here, the portion indicated by the alternate long-and-two-short-dash line represents a part of the arm member <b>114</b> which is to be extended to the door opening portion <b>202</b>, and which is positioned on a plane that differs from that on which the other parts are positioned.

0089The pipe <b>112</b> is connected to a channel switching unit <b>163</b> such as a solenoid valve or the like at one end thereof, and is provided so as to allow the purge gas to pass therethrough (see <figref idref="DRAWINGS">FIG. 7</figref>). Furthermore, the pipe <b>112</b> also serves as a rotational shaft, and is connected to the nozzle driving motor <b>166</b> through an unshown connecting member or the like. Furthermore, the pipe <b>112</b> is provided so as to pass through the arm member <b>114</b>. Moreover, unshown orifices are formed at the passing-through portion, which enables the purge gas to flow on the inside of the first nozzle unit <b>110</b>-<b>1</b>. With such an arrangement, the purge gas, which has passed through the inside of the pipe <b>112</b>, passes through the inside of the arm member <b>114</b> through the orifices, whereby the purge gas flows out from the nozzle outlets <b>111</b>.

0090The airtight space forming unit <b>120</b> provides a function of forming the airtight space B that communicates with the interior space of the wafer carrier <b>10</b> by connecting the airtight space forming unit <b>120</b> to the container opening <b>12</b> in an airtight manner as shown in <figref idref="DRAWINGS">FIG. 2</figref>. The airtight space forming unit <b>120</b> includes the storage portion <b>121</b>, a side-face cover member <b>122</b>, an upper portion cover member <b>123</b>, etc. The side-face cover member <b>122</b> is formed such that it can be stored in the storage portion <b>121</b> in a shape such that it follows the inner face of the storage portion <b>121</b>. Furthermore, an elevator mechanism <b>124</b>, which is driven by a side-face cover elevator motor <b>168</b> (see <figref idref="DRAWINGS">FIG. 7</figref>) described later, is provided, which enables the side-face cover member <b>122</b> to be raised and lowered from/to the storage portion <b>121</b>.

0091The elevator mechanism <b>124</b> includes a shaft <b>125</b> disposed near the wall face <b>201</b>, multiple ball slides <b>126</b> movably provided to the shaft <b>125</b>, etc. The shaft <b>125</b> is provided such that it passes through a tab formed at a lower portion of the side-face cover member <b>122</b>. The side-face cover member <b>122</b> is held through the ball slides <b>126</b> provided to the tab. Furthermore, an arm or the like is provided, which is connected to an unshown belt mechanism or the like driven by the side-face cover elevator motor <b>168</b>. The belt mechanism allows the side-face cover member <b>122</b> to be raised and lowered along the shaft <b>125</b>. The upper portion cover member <b>123</b> is provided near the upper end of the door opening portion <b>202</b> such that it faces the upper face of the storage portion <b>121</b>.

0092Upon raising the side-face cover member <b>122</b> from the storage portion <b>121</b> by the elevator mechanism <b>124</b>, and upon detaching the carrier door <b>16</b> from the container opening <b>12</b> by the load port door opening/closing mechanism <b>170</b>, the airtight space forming unit <b>120</b> provides the airtight space B defined by the upper face of the storage portion <b>121</b>, the side-face cover member <b>122</b>, and the upper-portion cover member <b>123</b>.

0093A gap (around 1 mm) is formed between the side-face cover member <b>122</b> and the upper-portion cover member <b>123</b>. Furthermore, another gap (around 0.5 to 1 mm) is formed between the carrier shell <b>11</b> and the wall face <b>201</b>. Now, let us consider the case in which the outflow of the purge gas flowing from the first nozzle unit <b>110</b>-<b>1</b> is greater than the inflow of the purge gas into the second nozzle unit <b>110</b>-<b>2</b>. In this case, such a structure allows the purge gas to flow to the outside of the airtight space B (e.g., the outside of the wafer carrier <b>10</b> or the processing space provided within the wafer processing apparatus).

0094The exhaust adjustment unit <b>130</b> includes an exhaust opening or the like having a function of adjusting the opening area thereof by an unshown micro-motor or the like. The exhaust adjustment unit <b>130</b> adjusts the opening area of the exhaust opening such that the pressure of the airtight space B is greater than the pressure of the outside of the airtight space B in a state in which the airtight space B is formed, and the atmosphere of the wafer carrier <b>10</b> is purged by the first nozzle unit <b>110</b>-<b>1</b>.

0095For example, let us consider the case in which there is an outflow of the purge gas of 100 L/min from the nozzle outlets <b>111</b> of the first nozzle unit <b>110</b>-<b>1</b> in a direction approximately parallel to the spaces A between the adjacent wafers <b>1</b>, and there is an inflow of 60 L/min into the second nozzle unit <b>110</b>-<b>2</b>. In this case, the exhaust adjustment unit <b>130</b> adjusts the opening area of the exhaust opening such that the purge gas flows to the outside of the airtight space B at a flow speed less than 40 L/min from the gap between the side-face cover member <b>122</b> and the upper-portion cover member <b>123</b>, the gap between the carrier shell <b>11</b> and the wall face <b>201</b>, and the exhaust opening of the exhaust adjustment unit <b>130</b>. Accordingly, the exhaust adjustment unit <b>130</b> allows the pressure of the airtight space B to be greater than the pressure of the outside. Such an arrangement enables the airtight space B to be protected from infiltration of air or the like from the gap between the side-face cover member <b>122</b> and the upper-portion cover member <b>123</b> and the gap between the carrier shell <b>11</b> and the wall face <b>201</b> in a sure manner.

0096The auxiliary nozzle unit <b>140</b> is provided within the upper-portion cover member <b>123</b>, and has a function of generating an outflow of the purge gas approximately downward, thereby forming a slender planar air curtain. The air curtain prevents the purge gas, which flows out from the nozzle outlets <b>111</b> of the first nozzle unit <b>110</b>-<b>1</b>, from flowing in a direction behind the first nozzle unit <b>110</b>-<b>1</b> (the side of the processing space provided within the wafer processing apparatus). This prevents the purge efficiency from dropping.

0097On the other hand, in the case that the load port <b>100</b> stops the purge, the side-face cover member <b>122</b> is stored within the storage portion <b>121</b> by the elevator mechanism <b>124</b>. Furthermore, the carrier door <b>16</b> is mounted to the container opening <b>12</b> of the carrier shell <b>11</b> by the load port door opening/closing mechanism <b>170</b>. Then, the load port <b>100</b> moves the moving base <b>103</b> such that it is distanced from the wall face <b>201</b>, whereupon the wafer carrier <b>10</b> is moved to a so-called home position.

0098Next, a description will be given regarding the nozzle outlets <b>111</b>. Note that <figref idref="DRAWINGS">FIG. 6A</figref> shows a state in which the first nozzle unit <b>110</b>-<b>1</b> has been extended to the door opening portion <b>202</b> such that it faces the wafers <b>1</b> stored within the wafer carrier <b>10</b>. <figref idref="DRAWINGS">FIG. 6B</figref> shows a cross-sectional view of the first nozzle unit <b>110</b>-<b>1</b>.

0099As shown in <figref idref="DRAWINGS">FIG. 6A</figref>, the nozzle outlets <b>111</b> are formed at predetermined intervals such that they are located at positions corresponding to the spaces A between the adjacent wafers <b>1</b> stored within the wafer carrier <b>10</b>. Such an arrangement provides a function of generating a uniform outflow of the purge gas in a direction approximately parallel to the spaces A between the adjacent wafers <b>1</b>. Furthermore, the nozzle outlets <b>111</b> are formed at predetermined intervals along a direction approximately oblique to the direction (vertical direction) along which the multiple wafers <b>1</b> are stored within the wafer carrier <b>10</b>. Accordingly, the nozzle outlets <b>1</b> generate a flow of the purge gas with the diffusion range thereof changing along the vertical direction. Such an arrangement allows the purge gas to be diffused in a wide range even in the case that the nozzle outlets <b>111</b> have been formed in a narrow region.

0100With such an arrangement, the nozzle outlets <b>111</b> are formed such that the thickness Y of the first nozzle unit <b>110</b>-<b>1</b> is twice or more (three times, for example) the diameter X of each nozzle outlet <b>111</b> based upon experimental results with respect to the directional stability of the purge gas.

0101Thus, the nozzle outlets <b>111</b> are capable of generating an outflow of the purge gas toward the spaces A between the wafers <b>1</b> with high efficiency. Such an arrangement allows the consumption of the purge gas to be reduced, thereby reducing costs for the purge.

0102As shown in <figref idref="DRAWINGS">FIG. 7</figref>, the load port <b>100</b> includes the channel switching unit <b>163</b>, an oxygen concentration sensor <b>164</b>, a storage unit <b>165</b>, the nozzle unit <b>110</b> comprising the first nozzle unit <b>110</b>-<b>1</b> and the second nozzle unit <b>110</b>-<b>2</b>, the nozzle driving motor <b>166</b>, a driver circuit <b>167</b>, the side-face cover member <b>122</b>, the side-face cover elevator motor <b>168</b>, a driver circuit <b>169</b>, the load port door opening/closing mechanism <b>170</b>, etc. With such an arrangement, these components are electrically connected to each other. On the other hand, the channel switching unit <b>163</b> is a solenoid valve or the like for switching the channel of the purge gas. The channel switching unit <b>163</b> is connected to a feed pump <b>161</b> for supplying the purge gas from an unshown purge gas tank, an intake pump <b>162</b> for drawing the purge gas such that it is transported to an unshown tank, and the nozzle unit <b>110</b>, through the pipe <b>112</b> etc.

0103A description will be given below regarding the operation of the load port <b>100</b>, mainly regarding a control unit <b>160</b> when performing the purge, with reference to <figref idref="DRAWINGS">FIGS. 7 and 8</figref>.

0104First, the control unit <b>160</b> outputs a signal D<b>3</b> to the side-face cover elevator motor <b>168</b> (S<b>101</b>). The side-face cover elevator motor <b>168</b> is connected to the control unit <b>160</b> via the driver circuit <b>169</b>. Upon the control unit <b>160</b> outputting the signal D<b>3</b>, the side-face cover elevator motor <b>168</b> drives the elevator mechanism <b>124</b> so as to raise the side-face cover member <b>122</b> stored within the storage portion <b>121</b>.

0105Next, the control unit <b>160</b> outputs a signal E<b>1</b> to the load port door opening/closing mechanism <b>170</b> (S<b>102</b>). Upon the control unit <b>160</b> outputting the signal E<b>1</b>, the load port door opening/closing mechanism <b>170</b> engages the load port door of the door opening portion <b>202</b> with the carrier door <b>16</b>, and detaches the carrier door <b>16</b> from the container opening <b>12</b>. In this stage, the airtight space B is formed, which communicates with the interior space of the wafer carrier <b>10</b>.

0106The control unit <b>160</b> outputs a signal D<b>1</b> to the nozzle driving motor <b>166</b> (S<b>103</b>). The nozzle driving motor <b>166</b> is connected to the control unit <b>160</b> via the driver circuit <b>167</b>. With such an arrangement, upon the control unit <b>160</b> outputting the signal D<b>1</b>, the nozzle driving motor <b>166</b> rotationally drives the pipe <b>112</b>, which is provided to the lower portion of the first nozzle unit <b>110</b>-<b>1</b> and which also serves as a rotational shaft, thereby extending the first nozzle unit <b>110</b>-<b>1</b> toward the door opening portion <b>202</b> from the side face of the door opening portion <b>202</b>.

0107The control unit <b>160</b> outputs a signal F<b>1</b> to the channel switching unit <b>163</b> (S<b>104</b>). Upon the control unit <b>160</b> outputting the signal F<b>1</b>, the channel switching unit <b>163</b> connects the feed pump <b>161</b> and the first nozzle portion <b>110</b>-<b>1</b>, and connects the intake pump <b>162</b> and the second nozzle unit <b>110</b>-<b>2</b>. In this stage, the purge gas flows out from the first nozzle unit <b>110</b>-<b>1</b>, and flows into the second nozzle unit <b>110</b>-<b>2</b>.

0108Next, the control unit <b>160</b> reads out a detection signal C detected by the oxygen concentration sensor <b>164</b> (S<b>105</b>). The oxygen concentration sensor <b>164</b> is a sensor for detecting the oxygen concentration of the atmosphere of the wafer carrier <b>10</b>, and has a function of detecting the detection signal C that is obtained by performing A/D conversion of a signal detected according to the oxygen concentration. The oxygen concentration is an indicator that indicates the degree of purging of the atmosphere of the wafer carrier <b>10</b>. Note that the purge is preferably performed with an oxygen concentration of between 0.1 to 1.0%, which indicates the optimum purge degree. Specifically, the oxygen concentration sensor <b>164</b> comprises a titania oxygen sensor or the like formed of titania (TiO₂) as a sensor element material, for example. The titania oxygen sensor detects the oxygen concentration based upon the change in the electrical resistance due to oxidation/reduction of the titania. In Step S<b>105</b>, the oxygen concentration is detected, instead of the nitrogen concentration. Examples of the reasons include the lower cost of the oxygen concentration sensor as compared to that of the nitrogen concentration sensor.

0109Next, the control unit <b>160</b> reads out a threshold signal C stored beforehand in the storage unit <b>165</b>, and which is used in a switching step for switching the flow of the purge gas. Then, the control unit <b>160</b> determines whether or not the detection signal C obtained in Step S<b>105</b> is equal to or less than the threshold signal C<b>1</b> (S<b>106</b>). The storage unit <b>165</b> comprises nonvolatile memory, and stores beforehand a predetermined range (e.g., a range of 0.1% to 1.0%) of the oxygen concentration that indicates the optimum purge degree. Furthermore, the storage unit <b>165</b> stores the oxygen concentration (e.g., 1.0%), which is used as a threshold for switching the flow of the purge gas, in the form of the threshold signal C<b>1</b>.

0110In the case that the detection signal C is equal to or less than the threshold signal C<b>1</b>, the control unit <b>160</b> determines that the purge has been sufficiently performed, and outputs a signal D<b>2</b> to the nozzle driving motor <b>166</b> (S<b>110</b>). Upon the control unit <b>160</b> outputting the signal D<b>2</b>, the nozzle driving motor <b>166</b> rotationally drives the pipe <b>112</b>, which also serves as a rotational shaft, in the rotational direction reverse to that when the signal D<b>1</b> is output, thereby retracting the first nozzle unit <b>110</b>-<b>1</b> to the side face of the door opening portion <b>202</b>.

0111On the other hand, in the case that the detection signal C is greater than the threshold signal C<b>1</b>, the control unit <b>160</b> determines that the purge thus performed is insufficient, and outputs a signal F<b>2</b> to the channel switching unit <b>163</b> (S<b>107</b>). Upon the control unit <b>160</b> outputting the signal F<b>2</b>, the channel switching unit <b>163</b> connects the intake pump <b>162</b> and the first nozzle unit <b>110</b>-<b>1</b>, and connects the feed pump <b>161</b> and the second nozzle unit <b>110</b>-<b>2</b>. Accordingly, the purge gas flows out from the second nozzle unit <b>110</b>-<b>2</b>, and flows into the first nozzle unit <b>110</b>-<b>1</b>.

0112Subsequently, after the readout of the detection signal C detected by the oxygen concentration sensor <b>164</b> again (S<b>108</b>), the control unit <b>160</b> reads out the aforementioned threshold signal C<b>1</b> from the storage unit <b>165</b>. Then, the control unit <b>160</b> determines whether or not the detection signal C obtained in Step S<b>108</b> is equal to or less than the threshold signal C<b>1</b> (S<b>109</b>).

0113In the case that the detection signal C is equal to or less than the threshold signal C<b>1</b>, the control unit <b>160</b> determines that the purge has been sufficiently performed, and the flow proceeds to the aforementioned Step S<b>110</b> where the control unit <b>160</b> outputs the signal D<b>2</b> to the nozzle driving motor <b>166</b>. On the other hand, in the case that the detection signal C is greater than the threshold signal C<b>1</b>, the control unit <b>160</b> determines that the purge thus performed is insufficient, and the flow returns to Step S<b>104</b> again where the control unit <b>160</b> outputs the signal F<b>1</b> to the channel switching unit <b>163</b>. That is to say, the control unit <b>160</b> controls the switching of the flow of the purge gas such that the detection signal C level is at the threshold signal C<b>1</b> or less, i.e., such that the purge is sufficiently performed.

0114Next, after Step S<b>110</b> where the first nozzle unit <b>110</b>-<b>1</b> has been retracted from the door opening portion <b>202</b>, the control unit <b>160</b> outputs a signal D<b>4</b> to the side-face cover elevator motor <b>168</b> (S<b>111</b>). Upon the control unit <b>160</b> outputting the signal D<b>4</b>, the side-face cover elevator motor <b>168</b> rotates in the direction reverse to that when the signal D<b>3</b> is output. This drives the elevator mechanism <b>124</b>, thereby storing the side-face cover member <b>122</b> within the storage portion <b>121</b>. In this stage, the airtight space B is released, i.e., the interior space of the wafer carrier <b>10</b> communicates with the processing space provided within the wafer processing apparatus.

0115Subsequently, the wafer <b>1</b> is transferred to the processing space of the wafer processing apparatus by the wafer transfer robot of the wafer processing apparatus. After predetermined processing, the wafer <b>1</b> is stored in the wafer carrier <b>10</b> again. Furthermore, upon completion of the predetermined processing for the wafers <b>1</b>, the carrier door <b>16</b> is closed by the load port door opening/closing mechanism <b>170</b>.

0116The load port <b>100</b> generates an outflow of the purge gas toward the spaces A between the adjacent wafers <b>1</b> with high efficiency. Such an arrangement reduces the period of time necessary to purge the atmosphere of the wafer carrier <b>10</b>. Also, such an arrangement enables the load port <b>100</b> to perform a predetermined purge step with a reduced flow of the purge gas.

0117The load port <b>100</b> has a function of extending/retracting the nozzle unit <b>110</b> toward/from the door opening portion <b>202</b>. Such an arrangement allows the distance between the wall face <b>201</b> and the end face of the storage portion <b>121</b> that faces the processing space to be reduced, for example. That is to say, such an arrangement can be made in accordance with the so-called SEMI standard.

0118The load port <b>100</b> controls the switching of the flow of the purge gas according to the oxygen concentration such that the purge degree of the atmosphere of the wafer carrier is at the optimum state. Accordingly, such an arrangement enables the atmosphere gas remaining around the curved inner wall <b>11</b><i>a </i>of the wafer carrier <b>10</b> to flow around the nozzle unit <b>110</b>, and enables the atmosphere gas to flow into the nozzle unit <b>110</b>, thereby providing high-precision purging.

0119A description will be given below regarding load ports according to other embodiments. Note that, in each embodiment, the same components as those in the above-described load port <b>100</b> are denoted by the same reference numerals, and description will be omitted regarding the functions thereof, etc., as appropriate.

Second Embodiment

0120As shown in <figref idref="DRAWINGS">FIG. 9</figref>, the difference between the load port <b>100</b>A and the load port <b>100</b> is that the load port <b>100</b>A includes a nozzle unit <b>110</b>A instead of the nozzle unit <b>110</b>.

0121The nozzle unit <b>110</b>A comprises thin plate-shaped members that can be stored in a storage portion <b>121</b>A. The nozzle unit <b>110</b>A includes nozzle outlets formed approximately over the entire area thereof such that they correspond to the spaces between the adjacent wafers <b>1</b>. The nozzle outlets are formed in the nozzle unit <b>110</b>A in the shape of a matrix at predetermined intervals. Each nozzle outlet is formed with a diameter equal to or smaller than ½ of the thickness of the nozzle unit <b>110</b>A (e.g., with a diameter of ⅓ of the thickness of the nozzle unit <b>110</b>A).

0122As described above, the nozzle unit <b>110</b>A comprises thin plate-shaped members. Accordingly, such an arrangement allows the nozzle unit <b>110</b>A to be raised from the storage portion <b>121</b>A by an appropriate nozzle unit elevator mechanism employing belts, ball screws, etc., without interference with the load port door opening/closing mechanism <b>170</b>.

0123Thus, the load port <b>100</b>A provides a function of raising the nozzle unit <b>110</b>A from the storage portion <b>121</b>, which is positioned at the lower end of the door opening portion <b>202</b>, by driving the nozzle unit elevator mechanism by the nozzle driving motor <b>166</b>, thereby enabling the nozzle unit <b>110</b>A to be extended to the door opening portion <b>202</b>.

0124Furthermore, the nozzle outlets are formed approximately over the entire area of the nozzle unit <b>110</b>A in the shape of a matrix such that they correspond to the spaces A between the adjacent wafers <b>1</b>. With such an arrangement, the purge gas flows out from approximately the entire area of a first nozzle unit <b>110</b>A-<b>1</b>, and flows into approximately the entire area of a second nozzle unit <b>110</b>A-<b>2</b>.

0125Thus, the load port <b>100</b>A provides a high-efficiency purge, thereby reducing the period of time necessary for the purge.

Third Embodiment

0126As shown in <figref idref="DRAWINGS">FIG. 10</figref>, the difference between the load port <b>100</b>B and the load port <b>100</b> is that the load port <b>100</b>B includes a nozzle unit <b>110</b>B instead of the nozzle unit <b>110</b>.

0127The nozzle unit <b>110</b>B comprises tube-shaped members that can be stored in a storage portion <b>121</b>B. The nozzle unit <b>110</b>B includes nozzle outlets formed at positions that correspond to the spaces A between the wafers <b>1</b>. Each nozzle outlet is formed with a diameter equal to or smaller than ½ of the thickness of the nozzle unit <b>110</b>B (e.g., with a diameter of ⅓ of the thickness of the nozzle unit <b>110</b>B) (see <figref idref="DRAWINGS">FIG. 6</figref>).

0128As described above, the nozzle unit <b>110</b>B is stored in the storage portion <b>121</b>B. Accordingly, an arrangement in which a pipe for supplying the purge gas is connected to the lower portion of the nozzle unit <b>110</b>B suffices. That is to say, there is no need to provide a particular mechanism for turning the nozzle unit <b>110</b> as shown in <figref idref="DRAWINGS">FIG. 2</figref>, for example.

0129Such an arrangement provides a simple mechanism for the lower portion of the nozzle unit <b>110</b>B. Also, such an arrangement has a function of raising the nozzle unit <b>110</b>B from the storage portion <b>121</b>, which is positioned at the lower end of the door opening portion <b>202</b>, by the nozzle driving motor <b>166</b> that drives the nozzle unit elevator mechanism having approximately the same configuration as that of the load port <b>100</b>A, thereby extending the nozzle unit <b>110</b>B toward the door opening portion <b>202</b>.

Fourth Embodiment

0130As shown in <figref idref="DRAWINGS">FIG. 11</figref>, the difference between the load port <b>100</b>C and the load port <b>100</b> is that the load port <b>100</b>C includes a nozzle unit <b>110</b>C instead of the nozzle unit <b>110</b>.

0131The nozzle unit <b>110</b>C comprises a first nozzle unit <b>110</b>C-<b>1</b> and a second nozzle unit <b>110</b>C-<b>2</b>, which are tube-shaped members, and which can be stored along an upper-portion cover member <b>123</b>A such that they are stacked on one another. The nozzle unit <b>110</b>C includes nozzle outlets formed at positions that correspond to the spaces A between the wafers <b>1</b>. Each nozzle outlet is formed with a diameter equal to or smaller than ½ of the thickness of the nozzle unit <b>1100</b> (e.g., with a diameter of ⅓ of the thickness of the nozzle unit <b>110</b>C) (see <figref idref="DRAWINGS">FIG. 6</figref>).

0132Furthermore, the load port <b>100</b>C includes an appropriate nozzle unit turning mechanism near the upper end of the door opening portion <b>202</b>, which allows the tube-shaped members of the nozzle unit <b>110</b>C to be turned with the left and the right ends of the upper portion of the door opening portion <b>202</b> serving as the turning axes.

0133Accordingly, with the load port <b>100</b>C, there is no need to provide a particular nozzle unit elevator mechanism to the storage portion <b>121</b>, thereby offering a simple mechanism of the storage portion <b>121</b>. With such an arrangement, the nozzle unit turning mechanism is driven by the nozzle driving motor <b>166</b> so as to turn the tube-shaped members of the nozzle unit <b>110</b>C with the left and the right ends of the upper portion of the door opening portion <b>202</b> serving as the turning axes, thereby extending the nozzle unit <b>110</b>C toward the door opening portion <b>202</b> from the position near the upper end of the door opening portion <b>202</b>.

Fifth Embodiment

0134As shown in <figref idref="DRAWINGS">FIGS. 12 and 13</figref>, the difference between the load port <b>100</b>D and the load port <b>100</b> is that the load port <b>100</b>D includes a nozzle unit <b>110</b>D instead of the nozzle unit <b>110</b>.

0135The nozzle unit <b>110</b>D comprises thin plate-shaped components which can be stored within the storage portion <b>121</b>C. The nozzle unit <b>110</b>D is arranged outside of the course H (see <figref idref="DRAWINGS">FIG. 4</figref>) of the outer edge of the wafer <b>1</b> which is transferred from the wafer carrier <b>10</b> to the wafer processing apparatus. The nozzle unit <b>110</b>D has nozzle outlets formed at positions corresponding to the spaces A between the wafers <b>1</b>. The nozzle outlets are formed in the nozzle unit <b>110</b>D at predetermined intervals along the longitudinal direction. Each nozzle outlet is formed with a diameter equal to or smaller than ½ of the thickness of the nozzle unit <b>110</b>D (e.g., with a diameter of ⅓ of the thickness of the nozzle unit <b>110</b>D) (see <figref idref="DRAWINGS">FIG. 6</figref>).

0136The load port <b>100</b>D includes a nozzle unit elevating/holding mechanism <b>127</b> that provides a function of extending the nozzle unit <b>110</b>D toward the door opening portion <b>202</b> from the storage portion <b>121</b>C, and an function of holding the nozzle unit <b>110</b>D at the extended position. The nozzle unit elevating/holding mechanism <b>127</b> includes: a slide member <b>128</b> formed at the lower portion of the nozzle unit <b>110</b>D; a holding member <b>129</b> that allows the nozzle unit <b>110</b>D to be held at the extended position; etc. The slide member <b>128</b> is mounted on a protrusion formed at the lower portion of the side-face cover member <b>122</b>, and includes ball slides or the like therewithin. Furthermore, the holding member <b>128</b> has a recess <b>128</b><i>a </i>formed in the side face that faces the holding member <b>129</b>. On the other hand, the holding member <b>129</b> includes a holding pin <b>129</b><i>a </i>that allows it to be engaged with the recess <b>128</b><i>a</i>. Furthermore, the holding pin <b>129</b><i>a </i>is provided in a manner that allows it to be extended and retracted toward/from the recess <b>128</b><i>a. </i>

0137With such an arrangement, as shown in <figref idref="DRAWINGS">FIG. 12</figref>, the nozzle unit <b>110</b>D is extended to the door opening portion <b>202</b> from the storage portion <b>121</b>C by the slide member <b>128</b> according to the operation of the elevator mechanism <b>124</b>. Subsequently, as shown in <figref idref="DRAWINGS">FIG. 13</figref>, the holding pin <b>129</b><i>a </i>of the holding member <b>129</b> is extended to the recess <b>128</b><i>a </i>of the slide unit <b>128</b> such that the holding pin <b>129</b><i>a </i>is engaged with the recess <b>128</b><i>a</i>, whereby the nozzle unit <b>110</b>D is held at the extended position. On the other hand, upon retracting the holding pin <b>129</b><i>a </i>from the recess <b>128</b><i>a</i>, the nozzle unit <b>110</b>D is retracted from the door opening portion <b>202</b> by the elevating operation of the aforementioned elevator mechanism <b>124</b>, whereby the nozzle unit <b>110</b>D is stored within the storage portion <b>121</b>C.

0138With such an arrangement, the nozzle unit <b>110</b>D is extended to the door opening portion <b>202</b> after the side-face cover member <b>122</b> has been stored within the storage portion <b>121</b> by the elevator mechanism <b>124</b>. Furthermore, in this case, the nozzle unit <b>110</b>D is arranged outside of the course H of the outer edge of the wafer <b>1</b>. Thus, such an arrangement allows the atmosphere of the wafer carrier <b>10</b> to be purged while transferring the wafer <b>1</b> to the processing space for predetermined processing by the wafer transfer robot of the wafer processing apparatus. This improves the operation efficiency.

0139Furthermore, the load port <b>100</b>D includes the nozzle unit elevating/holding mechanism <b>127</b> using the operation of the elevator mechanism <b>124</b>, instead of a particular turning mechanism provided for the storage portion <b>121</b> for turning the nozzle unit <b>110</b>, unlike the load port <b>100</b>. This provides a simpler mechanism of the storage portion <b>121</b>.

Sixth Embodiment

0140As shown in <figref idref="DRAWINGS">FIGS. 14A and 14B</figref>, the difference between the load port <b>100</b>E and the load port <b>100</b> is that the load port <b>100</b>E includes a nozzle unit <b>110</b>E instead of the nozzle unit <b>110</b>.

0141The nozzle unit <b>110</b>E comprises a first nozzle unit <b>110</b>E-<b>1</b>, a second nozzle unit <b>110</b>E-<b>2</b>, a third nozzle unit <b>110</b>E-<b>3</b>, a fourth nozzle unit <b>110</b>E-<b>4</b>, etc. Each of these nozzle components is formed in the shape of a thin plate, and can be stored within the storage portion <b>121</b>D. The first nozzle unit <b>110</b>E-<b>1</b> and the second nozzle unit <b>110</b>E-<b>2</b> are disposed near both side ends of the door opening portion <b>202</b>, and have a smaller width than that of the third nozzle unit <b>110</b>E-<b>3</b> and the fourth nozzle unit <b>110</b>E-<b>4</b> (e.g., with a width ratio of around 3:7).

0142When the first nozzle unit <b>110</b>E-<b>1</b> and the second nozzle unit <b>110</b>E-<b>2</b> are extended to the door opening portion <b>202</b>, the first nozzle unit <b>110</b>E-<b>1</b> and the second nozzle unit <b>110</b>E-<b>2</b> are positioned outside of the course H (see <figref idref="DRAWINGS">FIG. 4</figref>) of the outer edge of the wafer <b>1</b> which is transferred from the wafer carrier <b>10</b> to the wafer processing apparatus. On the other hand, the third nozzle unit <b>110</b>E-<b>3</b> and the fourth nozzle unit <b>110</b>E-<b>4</b> are disposed around the center of the door opening portion <b>202</b>.

0143The load port <b>100</b>E includes an unshown nozzle unit elevator mechanism (described later) for raising the first nozzle unit <b>110</b>E-<b>1</b>, the second nozzle unit <b>110</b>E-<b>2</b>, the third nozzle unit <b>110</b>E-<b>3</b>, and the fourth nozzle unit <b>110</b>E-<b>4</b>. With such an arrangement, each nozzle component of the nozzle unit <b>110</b>E is formed in the shape of a thin plate. Such an arrangement enables the nozzle unit elevator mechanism to raise the nozzle components of the nozzle unit <b>110</b>E independently of one another without interference with the load port door opening/closing mechanism <b>170</b>, thereby extending the nozzle components of the nozzle unit <b>110</b>E to the door opening portion <b>202</b> independently of one another.

0144The nozzle unit <b>110</b>E includes nozzle outlets formed approximately over the entire area thereof such that they correspond to the spaces between the adjacent wafers <b>1</b>. The nozzle outlets are formed in the nozzle unit <b>110</b>E in the shape of a matrix at predetermined intervals. Each nozzle outlet is formed with a diameter equal to or smaller than ½ of the thickness of the nozzle unit <b>110</b>E (e.g., with a diameter of ⅓ of the thickness of the nozzle unit <b>110</b>E).

0145With such an arrangement, the nozzle outlets are formed approximately over the entire area of the nozzle unit <b>110</b>E in the shape of a matrix such that they correspond to the spaces A between the adjacent wafers <b>1</b>. Such an arrangement generates an outflow of the purge gas from approximately the entire area of the first nozzle unit <b>110</b>E-<b>1</b> and the third nozzle unit <b>110</b>E-<b>3</b>, and an inflow thereof into approximately the entire area of the second nozzle unit <b>110</b>E-<b>2</b> and the fourth nozzle unit <b>110</b>E-<b>4</b>. Thus, the load port <b>100</b>E provides high-efficiency, thereby reducing the period of time necessary for the purge.

0146Next, a description will be given regarding the nozzle unit elevator mechanism of the load port <b>100</b>E.

0147The nozzle unit elevator mechanism includes: a motor for directly driving the third nozzle unit <b>110</b>E-<b>3</b> and the fourth nozzle unit <b>110</b>E-<b>4</b>; an unshown nozzle unit engaging pin for engaging the third nozzle unit <b>110</b>E-<b>3</b> and the fourth nozzle unit <b>110</b>E-<b>4</b> with the first nozzle unit <b>110</b>E-<b>1</b> and the second nozzle unit <b>110</b>E-<b>2</b>; an unshown side-cover member engaging pin for engaging the third nozzle unit <b>110</b>E-<b>3</b> and the fourth nozzle unit <b>110</b>E-<b>4</b> with the side-face cover member <b>122</b>; etc.

0148In an early stage of the purge step, the nozzle unit elevator mechanism extends the nozzle unit engaging pin, thereby engaging the third nozzle unit <b>110</b>E-<b>3</b> and the fourth nozzle unit <b>110</b>E-<b>4</b> with the first nozzle unit <b>110</b>E-<b>1</b> and the second nozzle unit <b>110</b>E-<b>2</b>. At the same time, the nozzle unit elevator mechanism extends the side-face cover member engaging pin, thereby engaging the third nozzle unit <b>110</b>E-<b>3</b> and the fourth nozzle unit <b>110</b>E-<b>4</b> with the side-face cover member <b>122</b>.

0149Next, upon driving the motor, the nozzle unit elevator mechanism raises the first nozzle unit <b>110</b>E-<b>1</b> and the second nozzle unit <b>110</b>E-<b>2</b> to the door opening portion <b>202</b>, as well as raising the third nozzle unit <b>110</b>E-<b>3</b> and the fourth nozzle unit <b>110</b>E-<b>4</b> to the door opening portion <b>202</b>. Furthermore, the nozzle unit elevator mechanism raises the side-face cover member <b>122</b> from the storage portion <b>121</b>D.

0150In this stage, the load port <b>100</b>E enter a state in which the first nozzle unit <b>110</b>E-<b>1</b> through the fourth nozzle unit <b>110</b>E-<b>4</b> are raised to the door opening portion <b>202</b>, and the side-face cover member <b>122</b> is also raised from the storage portion <b>121</b>D so as to form the airtight space B as shown in <figref idref="DRAWINGS">FIG. 14A</figref>. In this state, the load port <b>100</b>E purges the atmosphere of the wafer carrier <b>10</b>.

0151Now, let us consider the case in which, after the purge step described above, the wafer <b>1</b> is transferred to the processing space provided within the wafer processing apparatus for predetermined processing. In this case, the load port <b>100</b>E stores the third nozzle unit <b>110</b>E-<b>3</b>, the fourth nozzle unit <b>110</b>E-<b>4</b>, and the side-face cover member <b>122</b> within the storage portion <b>121</b>D by the nozzle unit elevator mechanism, as shown in <figref idref="DRAWINGS">FIG. 14B</figref>. In order to perform such an operation, the load port <b>100</b>E retracts the nozzle unit engaging pin of the nozzle unit elevator mechanism. At the same time, the load port <b>100</b>E holds the first nozzle unit <b>110</b>E-<b>1</b> and the second nozzle unit <b>110</b>E-<b>2</b> at the extended positions using a mechanism similar to that including the holding pin <b>129</b><i>a </i>and the recess <b>128</b><i>a </i>of the nozzle unit elevating/holding mechanism <b>127</b> described above (see <figref idref="DRAWINGS">FIGS. 12 and 13</figref>). Such an arrangement enables the load port <b>100</b>E to perform purging using the first nozzle unit <b>110</b>E-<b>1</b> and the second nozzle unit <b>110</b>E-<b>2</b> while transferring the wafer <b>1</b>.

0152Furthermore, the load port <b>100</b>E retracts the side-face cover engaging pin of the nozzle unit elevator mechanism, raises the third nozzle unit <b>110</b>E-<b>3</b> and the fourth nozzle unit <b>110</b>E-<b>4</b> to the door opening portion <b>202</b>, and a purge is performed using the first nozzle unit <b>1</b> through the fourth nozzle unit <b>4</b> again while predetermined processing is performed for the wafer <b>1</b>, as shown in <figref idref="DRAWINGS">FIG. 14A</figref>.

0153Before the wafer <b>1</b> subjected to the predetermined processing is stored within the wafer carrier <b>10</b> again, the load port <b>100</b>E stores the third nozzle unit <b>110</b>E-<b>3</b> and the fourth nozzle unit <b>110</b>E-<b>4</b> within the storage portion <b>121</b>D by the nozzle unit elevator mechanism. Such an arrangement allows the load port <b>100</b>E to perform the purge using the first nozzle unit <b>110</b>E-<b>1</b> and the second nozzle unit <b>110</b>E-<b>2</b> while transferring the wafer <b>1</b>. This improves the operation efficiency as compared with the above-described load port <b>100</b>A.

0154Furthermore, the load port <b>100</b>E can raise/lower the third nozzle unit <b>110</b>E-<b>3</b> and the fourth nozzle unit <b>110</b>E-<b>4</b> for each step for transferring the wafer <b>1</b>. Such an arrangement prevents deterioration in the purge state during the processing, as compared with the load ports <b>100</b>, <b>100</b>B, <b>100</b>C, and <b>100</b>D described above.

0155After completion of the predetermined processing for all the wafers <b>1</b> stored within the wafer carrier <b>10</b>, the load port <b>100</b>E extends the nozzle unit engaging pin of the nozzle unit elevator mechanism, thereby engaging the third nozzle unit <b>110</b>E-<b>3</b> and the fourth nozzle unit <b>110</b>E-<b>4</b> with the first nozzle unit <b>110</b>E-<b>1</b> and the second nozzle unit <b>110</b>E-<b>2</b>. Furthermore, the load port <b>100</b>E retracts the first nozzle unit <b>110</b>E-<b>1</b> and the second nozzle unit <b>110</b>E-<b>2</b> from their extended positions using the same mechanism as the nozzle unit elevating/holding mechanism <b>127</b>, thereby storing the first nozzle unit <b>110</b>E-<b>1</b> and the second nozzle unit <b>110</b>E-<b>2</b> within the storage portion <b>121</b>D, as well as storing the third nozzle unit <b>110</b>E-<b>3</b> and the fourth nozzle unit <b>110</b>E-<b>4</b> within the storage portion <b>121</b>D. Subsequently, the wafer carrier <b>10</b> is closed with the carrier door <b>16</b> by the load port door opening/closing mechanism <b>170</b>.

Seventh Embodiment

0156A load port <b>700</b> according to a seventh embodiment is similar to the second embodiment, except for the modification made to the second nozzle unit <b>110</b>A-<b>2</b> of the second embodiment.

0157<figref idref="DRAWINGS">FIG. 15</figref> is a plan sectional view showing the load port <b>700</b> and a wafer carrier according to the seventh embodiment. <figref idref="DRAWINGS">FIG. 16</figref> is an enlarged view (sectional view along line <b>16</b>-<b>16</b> of <figref idref="DRAWINGS">FIG. 15</figref>) showing a gas supply plate <b>710</b>-<b>1</b> and a partition <b>710</b>-<b>2</b> according to the seventh embodiment when viewed from nozzles. <figref idref="DRAWINGS">FIG. 17</figref> is a side sectional view showing the load port <b>700</b> and the wafer carrier <b>10</b> according to the seventh embodiment.

0158Although, <figref idref="DRAWINGS">FIG. 15</figref> typically shows three pieces of outlet nozzles and inlet nozzles respectively, a large number of outlet nozzles <b>711</b>-<b>1</b> are provided at the gas supply plate <b>710</b>-<b>1</b> and a large number of inlet nozzles <b>711</b>-<b>2</b> are provided at the partition <b>710</b>-<b>2</b>, as shown in <figref idref="DRAWINGS">FIG. 16</figref>.

0159In addition, descriptions will be provided for embodiments and figures below according to the coordinates as shown in the plan sectional view of <figref idref="DRAWINGS">FIG. 15</figref>: a left-right direction X, depth direction Y and vertical direction Z perpendicular to a surface of a wafer <b>1</b>.

Setup of Load Port

700

0160As shown in <figref idref="DRAWINGS">FIGS. 15-17</figref>, the load port <b>700</b> includes the gas supply plate <b>710</b>-<b>1</b>, the partition <b>710</b>-<b>2</b>, an auxiliary nozzle unit <b>740</b> (gas outlet), and an intermediate room A<b>2</b>.

0161The gas supply plate <b>710</b>-<b>1</b> corresponds to the first nozzle unit <b>110</b>A-<b>1</b> (see <figref idref="DRAWINGS">FIG. 9</figref>) of the second embodiment. As shown in <figref idref="DRAWINGS">FIG. 15</figref>, the gas supply plate <b>710</b>-<b>1</b> is shaped like a plate.

0162The gas supply plate <b>710</b>-<b>1</b> is disposed in a region C<b>1</b> of a region C facing an aperture of the wafer carrier <b>10</b> on a left side X<b>1</b> (one side) with respect a center line CL along the depth direction Y in which the wafer <b>1</b> is conveyed. In this manner, the gas supply plate <b>710</b>-<b>1</b> is disposed as separating the region C<b>1</b>, which constitutes a part of a region between the intermediate room A<b>2</b> and the wafer carrier <b>10</b>.

0163The gas supply plate <b>710</b>-<b>1</b> is disposed such that there is a gap G<b>1</b> that allows a carrier space A<b>1</b> inside the wafer carrier <b>10</b> to fluidly communicate with the intermediate room A<b>2</b>. The gap G<b>1</b> is configured to prevent the gas supply plate <b>710</b>-<b>1</b> from coming into contact not only with a cover <b>721</b> of an accommodating portion but also with a fixed wall <b>730</b> so as to restrict the generation of dust, when the gas supply plate <b>710</b>-<b>1</b> is driven by a drive unit.

0164The gas supply plate <b>710</b>-<b>1</b> includes a plurality of outlet nozzles <b>711</b>-<b>1</b>. As show in <figref idref="DRAWINGS">FIG. 16</figref>, the outlet nozzles <b>711</b>-<b>1</b> are provided at a face of the gas supply plate <b>710</b>-<b>1</b> that faces the wafer carrier <b>10</b>.

0165The outlet nozzles <b>711</b>-<b>1</b> are each formed in agreement with a gap between adjacent wafers. The outlet nozzles <b>711</b>-<b>1</b> are disposed at uniform intervals in the left-right direction X parallel to the surfaces of wafers <b>1</b>. In addition, the outlet nozzles <b>711</b>-<b>1</b> are disposed at uniform intervals in the vertical direction Z in which the wafers <b>1</b> are layered. Accordingly, the outlet nozzles <b>711</b>-<b>1</b> are formed uniformly in an entirety of the gas supply plate <b>710</b>-<b>1</b>.

0166As shown in <figref idref="DRAWINGS">FIG. 15</figref>, the outlet nozzles <b>711</b>-<b>1</b> is connected to a purge gas supply unit (not shown) through a pipe <b>712</b>. The purge gas is supplied to the outlet nozzles <b>711</b>-<b>1</b> by a pump and the like.

0167As shown in <figref idref="DRAWINGS">FIG. 15</figref>, the partition <b>710</b>-<b>2</b> corresponds to the second nozzle unit <b>110</b>A-<b>2</b> of the second embodiment (see <figref idref="DRAWINGS">FIG. 9</figref>). The partition <b>710</b>-<b>2</b> is shaped like a plate.

0168The partition <b>710</b>-<b>2</b> is disposed in a region C<b>2</b> of the region C facing the aperture of the wafer carrier <b>10</b> on a right side X<b>2</b> (another side) opposite to the gas supply plate <b>710</b>-<b>1</b> with respect the center line CL. In this manner, the partition <b>710</b>-<b>2</b> is disposed as separating the region C<b>2</b>, which constitutes a part of a region between the intermediate room A<b>2</b> and the carrier space A<b>1</b>. The partition <b>710</b>-<b>2</b> is disposed such that there are a gap C<b>3</b> between the partition <b>710</b>-<b>2</b> and the gas supply plate <b>710</b>-<b>1</b>. The gap C<b>3</b> is formed along the center line CL.

0169In a similar manner to the gas supply plate <b>710</b>-<b>1</b>, the partition <b>710</b>-<b>2</b> is disposed to have a gap G<b>2</b> that causes the carrier space A<b>1</b> to fluidly communicate with the intermediate room A<b>2</b>.

0170The partition <b>710</b>-<b>2</b> includes a plurality of inlet nozzles <b>711</b>-<b>2</b>. As shown in <figref idref="DRAWINGS">FIG. 16</figref>, the inlet nozzles <b>711</b>-<b>2</b> are each disposed in agreement with a gap between adjacent wafers <b>1</b>, and at uniform intervals in the left-right direction X and vertical direction Z respectively to be formed in an entirety of the partition <b>710</b>-<b>2</b>, in a similar manner to the outlet nozzles <b>711</b>-<b>1</b>.

0171As shown in <figref idref="DRAWINGS">FIG. 15</figref>, the inlet nozzles <b>711</b>-<b>2</b> are through apertures that penetrate the partition <b>710</b>-<b>2</b> from the carrier space A<b>1</b> to the intermediate room A<b>2</b> in the depth direction Y. A pump, pipe or the like to suck the purge gas is not connected to the inlet nozzles <b>711</b>-<b>2</b>, differing from the outlet nozzles <b>711</b>-<b>1</b>.

0172As shown in <figref idref="DRAWINGS">FIG. 17</figref>, the auxiliary nozzle unit <b>740</b> corresponds to the auxiliary nozzle unit <b>140</b> (see <figref idref="DRAWINGS">FIG. 9</figref>) of the second embodiment.

0173It should be noted that the auxiliary nozzle unit <b>740</b> is configured like a plate instead of a cylinder. Since the plate configuration allows nozzles for discharging the purge gas to be formed at an entire lower surface (surface facing inside the intermediate room A<b>2</b>) of the auxiliary nozzle unit <b>740</b>, it is possible to cause the purge gas to move downward efficiently.

0174The intermediate room A<b>2</b> corresponds to the airtight space B of the second embodiment (see <figref idref="DRAWINGS">FIG. 9</figref>). When the gas replacement is performed, an elevator mechanism (see the elevator mechanism <b>124</b> in <figref idref="DRAWINGS">FIG. 13</figref>) drives the gas supply plate <b>710</b>-<b>1</b>, the partition <b>710</b>-<b>2</b>, and the side cover member <b>722</b> to be lifted, such that these components form the intermediate room A<b>2</b>.

Gas Replacement Operation Performed by Load Port

700

0175The gas replacement operation performed by the load port <b>700</b> will be described. Since controlling of the load port <b>700</b> during the gas replacement is similar to the embodiments <b>1</b> and <b>2</b>, descriptions will be focused on the differences from the embodiments <b>1</b> and <b>2</b>.

0176A control unit (see the control unit <b>160</b> of <figref idref="DRAWINGS">FIG. 7</figref>) performs the gas replacement operation according to the following steps.

0000Gas Movement from Carrier Space A<b>1</b> to Intermediate Room A<b>2</b>

0177(1) As described above, the elevator mechanism drives the gas supply plate <b>710</b>-<b>1</b>, the partition <b>710</b>-<b>2</b> and the side cover member <b>722</b> to be disposed as shown in <figref idref="DRAWINGS">FIGS. 15 and 17</figref>. More specifically, the gas supply plate <b>710</b>-<b>1</b> and the partition <b>710</b>-<b>2</b> are disposed in the respective regions C<b>1</b> and C<b>2</b> in the region facing the aperture of the wafer carrier <b>10</b>, opposite to each other with respect to the center line CL. At the same time, the side cover member has already been driven upward. In this manner, the intermediate room A<b>2</b> is formed.

0178(2) As shown in <figref idref="DRAWINGS">FIG. 17</figref>, the purge gas is supplied through the auxiliary nozzle unit <b>740</b> so as to create a flow of the purge gas descending in the intermediate room A<b>2</b> (see an arrow E<b>1</b>).

0179(3) As shown in <figref idref="DRAWINGS">FIG. 17</figref>, the purge gas is supplied from the gas supply plate <b>710</b>-<b>1</b> towards gaps between adjacent wafers <b>1</b> in the carrier space A<b>1</b>. It should be noted that steps (3) and (4) may be performed simultaneously.

0180(4) The control unit controls an amount of the purge gas such that a pressure P<b>2</b> of the intermediate room A<b>2</b> is lower than a pressure P<b>1</b> of the carrier space A<b>1</b>. Since the carrier space A<b>1</b> is maintained airtight to some degree by the gas supply plate <b>710</b>-<b>1</b> and the partition <b>710</b>-<b>2</b>, it is relatively easy to set the pressure P<b>1</b> higher than the pressure P<b>2</b>.

0181Descriptions in detail will be provided for the gas flow in the carrier space A<b>1</b> while step (4) is being performed.

0182(4-1) As shown in <figref idref="DRAWINGS">FIG. 15</figref>, the purge gas exiting from the outlet nozzles <b>711</b>-<b>1</b> moves substantially straight towards an inner wall <b>11</b><i>a </i>of the wafer carrier <b>10</b> in the depth direction Y in a left half region A<b>1</b>-<b>1</b> of the carrier space A<b>1</b> (see an arrow D<b>1</b>).

0183(4-2) A gas moving towards the inner wall <b>11</b><i>a </i>collides with a left curved surface <b>11</b><i>a</i>-<b>1</b> to turn along the left curved surface <b>11</b><i>a</i>-<b>1</b> (see an arrow D<b>2</b>). And the gas moves towards the partition <b>710</b>-<b>2</b> in a right half region A<b>1</b>-<b>2</b> of the carrier space A<b>1</b> (see an arrow D<b>3</b>). Since the gas collides with the curved surface <b>11</b><i>a</i>-<b>1</b> not perpendicularly but having some angle, it may be similar that the gas collides with a slope. Accordingly, the curved surface <b>11</b><i>a</i>-<b>1</b> does not apply a large amount of resistance to the gas, but helps the gas turn naturally.

0184(4-3) Since the gas having moved towards the partition <b>710</b>-<b>2</b> collides with the partition <b>710</b>-<b>2</b>, the pressure of a region A<b>1</b>-<b>3</b> (region closer to the wafer carrier <b>10</b> than the partition <b>710</b>-<b>2</b>) adjacent to the partition <b>710</b>-<b>2</b> increases. Accordingly, the gas bypasses the region A<b>1</b>-<b>3</b> to go back into the left region A<b>1</b>-<b>1</b> (see an arrow D<b>4</b>).

0185(4-4) The gas having returned to the left region A<b>1</b>-<b>1</b> moves again towards the inner wall <b>11</b><i>a </i>along with the purge gas supplied from the outlet nozzle <b>711</b>-<b>1</b> (see the arrow D<b>1</b>).

0186With the (4-1) to (4-4) the gas inside the carrier space A<b>1</b> circulates between the wafers <b>1</b> over a substantially entire region of the carrier space A<b>1</b> in one rotational direction (clockwise direction in <figref idref="DRAWINGS">FIG. 15</figref>).

0187(4-5) As described above, the pressure P<b>2</b> of the intermediate room A<b>2</b> is lower than the pressure P<b>1</b> of the carrier space A<b>1</b>. Due to this pressure difference, a part of the gas in the region A<b>1</b>-<b>3</b> adjacent to the partition <b>710</b>-<b>2</b> moves into the intermediate room A<b>2</b> through the gap C<b>3</b>, the inlet nozzles <b>711</b>-<b>2</b> or the gap G<b>2</b> (see arrows D<b>5</b>, D<b>6</b> and D<b>7</b>).

0188As described above, the load port <b>700</b>, which causes the gas inside the carrier space A<b>1</b> to circulate and move into the intermediate room A<b>2</b>, provides the following advantages.

0189The outlet nozzles <b>711</b>-<b>1</b> are uniformly arranged over the entirety of the gas supply plate <b>710</b>-<b>1</b>. This makes it possible to lower the velocity of the purge gas exiting from the outlet nozzles <b>711</b>-<b>1</b> and decrease accordingly an amount of the purge gas per outlet nozzle <b>711</b>-<b>1</b>, even if the large amount of purge gas is supplied by the gas supply plate <b>710</b>-<b>1</b> at a time. In this manner, it is possible to lower the velocity of the gas inside the carrier space A<b>1</b> and prevent an occurrence of a turbulent flow, creating a laminar flow on the surface of a wafer <b>1</b>.

0190As described above, the gas forming a laminar flow on the surface of a wafer <b>1</b> circulates uniformly in the carrier space A<b>1</b> and removes foreign materials (particles and moisture) adhered on the surface of the wafer <b>1</b>.

0191In addition, the gas inside the carrier space A<b>1</b> moves from an inner periphery to an outer periphery of the wafer <b>1</b>. Accordingly, the foreign materials move from the inner periphery to the outer periphery. The foreign materials having moved to the outer periphery move from the wafer carrier <b>10</b> into the intermediate room A<b>2</b> through the gap C<b>3</b> or the inlet nozzles <b>711</b>-<b>2</b> along with the gas that moves along the partition <b>710</b>-<b>2</b> in the region A<b>1</b>-<b>3</b> (see the arrows D<b>5</b>, D<b>6</b> and D<b>7</b>).

0192Since the load port <b>700</b> promptly supplies the purge gas between the wafers <b>1</b> and discharges a gas originally existed in the carrier space A<b>1</b>, it is possible to perform the gas replacement operation within a short period of time. In addition, it is possible to discharge the foreign materials adhered to the wafers <b>1</b> from the carrier space A<b>1</b> into the intermediate room <b>2</b>. It should be noted that since the gas inside the intermediate room A<b>2</b> descends as shown in <figref idref="DRAWINGS">FIG. 17</figref>, the gas coming from the carrier space A<b>1</b> also descends to move into an accommodating portion so as to be collected (see an arrow E<b>1</b>).

0193Descriptions of a gas flow will now be provided for a case which differs from the seventh embodiment in that the gas supply plate <b>710</b>-<b>1</b> is disposed at a substantially central position of the region C facing the aperture of the wafer carrier <b>10</b> and the partition <b>710</b>-<b>2</b> is omitted.

0194When the gas supply plate <b>710</b>-<b>1</b> supplies the purge gas, the gas originally existed inside the carrier space A<b>1</b> collides with the vicinities of a central portion of the inner wall <b>11</b><i>a </i>and branches off in the left-right direction X. Since this gas moves in a direction substantially perpendicular to the inner wall <b>11</b><i>a</i>, it collides with the vicinities of the central portion of the inner wall <b>11</b><i>a </i>in a front direction. Accordingly, this gas loses momentum to move in left and right directions. In addition, this gas in the vicinity of the central portion of the inner wall <b>11</b><i>a </i>tends to stagnate to decrease its flow velocity.

0195Furthermore, since the partition <b>710</b>-<b>2</b> is omitted, the gas branches off in the left and right directions. As a result, the most amount of the gas moves into the intermediate room A<b>2</b> even if the gas comes back towards the aperture of the wafer carrier <b>10</b>.

0196As described above, this case does not work well in circulating the gas originally existed inside the carrier space A<b>1</b>. Since the gas inside the carrier space A<b>1</b> has a larger difference in the distribution of its velocities, it is difficult for the gas to move at a uniform velocity. Accordingly, it is necessary to increase the velocity of the purge gas exiting from the gas supply plate <b>710</b>-<b>1</b> in order to remedy a region where the velocity is relatively low, such that foreign materials adhered to a wafer <b>1</b> are removed. This requires increasing the velocities over an entirety of the gas inside the carrier space A<b>1</b>. However, it may be likely that a turbulent flow occurs on the surface of the wafer <b>1</b> and the removal of the foreign materials adhered to the wafer <b>1</b> is not effectively performed.

0197If the gas supply plate <b>710</b>-<b>1</b> is disposed at the substantially central position of the region C facing the aperture of the wafer carrier <b>10</b> and the partition <b>710</b>-<b>2</b> is omitted, it will decrease the momentum to circulate the gas inside the carrier space A<b>1</b> and degrade the performance to remove the foreign materials adhered to the wafer <b>1</b>.

0198With respect to the load port <b>700</b> according to the seventh embodiment, it is possible to increase the efficiency of gas replacement by replacing the gas inside the carrier space A<b>1</b> while circulating the gas in one direction.

0199In addition, even if a part of the gas inside the intermediate room A<b>2</b> moves into the carrier space A<b>1</b>, it is possible for the load port <b>700</b> to prevent a considerable decrease in the gas replacement efficiency.

Eighth Embodiment

0200A load port <b>800</b> differs from the seventh embodiment only in that modifications are made to the gas supply plate <b>710</b>-<b>1</b> and partition <b>710</b>-<b>2</b>.

0201The same symbols or symbols having the same symbols at the last part (last two digits) are used for components having the same functions as the seventh embodiment in describing the eighth embodiment and drawings. And the descriptions will not be repeated for these similar components.

0202<figref idref="DRAWINGS">FIG. 18</figref> is a plan sectional view showing the load port <b>800</b> and a wafer carrier <b>10</b> according to an eighth embodiment (corresponding to <figref idref="DRAWINGS">FIG. 15</figref>).

Setup of Load Port

800

0203The load port <b>800</b> includes a gas supply plate <b>810</b>-<b>1</b> and a partition <b>810</b>-<b>2</b>. A gap C<b>3</b> between the gas supply plate <b>810</b>-<b>1</b> and the partition <b>810</b>-<b>2</b> is greater than the seventh embodiment. In other words, the gas supply plate <b>810</b>-<b>1</b> and the partition <b>810</b>-<b>2</b> each have a dimension in a left-right direction X smaller than the seventh embodiment. The partition <b>810</b>-<b>2</b> is a flat plate without inlet nozzles.

Gas Replacement Operation Performed by Load Port

800

0204The gas replacement operation performed by the load port <b>800</b> will be described. As controlling of the load port <b>800</b> is similar to the seventh embodiment, descriptions will be focused on differences from the seventh embodiment.

0205A gas circulates in a carrier space A<b>1</b> in a similar manner to the seventh embodiment. As described above, the inlet nozzles are not provided for the partition <b>810</b>-<b>2</b>. Accordingly, a pressure of a region A<b>1</b>-<b>3</b> adjacent to the partition <b>810</b>-<b>2</b> is greater than the seventh embodiment. This causes the gas to increase momentum to bypass the region A<b>1</b>-<b>3</b> greater than the seventh embodiment (see an arrow D<b>804</b>). In this manner, this gas inside the carrier space A<b>1</b> tends to circulate more easily than the seventh embodiment.

0206With respect to pressures, a pressure P<b>2</b> of an intermediate room A<b>2</b> is lower than a pressure P<b>1</b> of the carrier space A<b>1</b> in a similar manner to the seventh embodiment. The resulting pressure difference causes a part of the gas of the region A<b>1</b>-<b>3</b> adjacent to the partition <b>810</b>-<b>2</b> to move into the intermediate room A<b>2</b> through the gap C<b>3</b> or gap G<b>2</b> (see arrows D<b>805</b> and <b>807</b>). As described above, the gap C<b>3</b> between the gas supply plate <b>810</b>-<b>1</b> and the partition <b>810</b>-<b>2</b> is greater than that of the seventh embodiment. Accordingly, a sufficient amount of gas of the region A<b>1</b>-<b>3</b> moves into the intermediate room A<b>2</b> through the gap C<b>3</b>, even if the partition <b>810</b>-<b>2</b> has no inlet nozzles.

0207The load port <b>800</b> of the eighth embodiment, which has the partition <b>810</b>-<b>2</b> of a flat plate, increases the efficiency of replacing the gas with a simple setup.

Ninth Embodiment

0208In a load port <b>900</b> of a ninth embodiment, the cover <b>721</b> of the seventh embodiment is modified to a cover <b>921</b>.

0209<figref idref="DRAWINGS">FIG. 19</figref> is a perspective view showing the load port <b>900</b> according to the ninth embodiment. <figref idref="DRAWINGS">FIG. 20</figref> is a plan sectional view (sectional view along line <b>20</b>-<b>20</b> of <figref idref="DRAWINGS">FIG. 19</figref>) showing the load port <b>900</b> and a wafer carrier <b>10</b> according to the ninth embodiment. The same symbols or symbols having the same symbols at the last part (last two digits) are used for components having the same functions as the seventh embodiment in describing the ninth embodiment and drawings. And the descriptions will not be repeated for these similar components.

Setup of Load Port

900

0210As shown in <figref idref="DRAWINGS">FIGS. 19 and 20</figref>, the cover <b>921</b> includes a side wall <b>921</b><i>a</i>. The side wall <b>921</b><i>a </i>projects from a fixed wall <b>930</b> towards a receiving room A<b>3</b>. An intermediate room A<b>2</b> is formed while enclosed by the side wall <b>921</b><i>a </i>and a side cover member <b>922</b>. A part of a side face of a side portion <b>922</b><i>a </i>of the side cover member <b>922</b> faces the side wall <b>921</b><i>a</i>. Accordingly, a narrow passage <b>921</b><i>b </i>that causes the intermediate room A<b>2</b> to fluidly communicate with the receiving room A<b>3</b> is formed between the side wall <b>921</b><i>a </i>and the side cover member <b>922</b>.

0211<figref idref="DRAWINGS">FIG. 21</figref> is an enlarged view (inside a long dashed double-short dotted line of <figref idref="DRAWINGS">FIG. 20</figref>) showing the load port <b>900</b> according to the ninth embodiment.

0212Suppose a case in which a pressure P<b>2</b> of the intermediate room A<b>2</b> and a pressure P<b>3</b> of the receiving room A<b>3</b> satisfy: P<b>2</b> is lower than P<b>3</b>. In this case, a gas inside the receiving room A<b>3</b> tends to enter the intermediate room A<b>2</b> through the passage <b>921</b><i>b </i>(see an arrow D<b>908</b>). However, the width of the passage <b>921</b><i>b </i>is so small that a pressure of a gas in the passage <b>921</b><i>b </i>is smaller than the pressure P<b>3</b> due to the fluid resistance. It should be noted that passages F<b>2</b> and F<b>3</b> are formed on a lower side Z<b>1</b> and an upper side Z<b>2</b> respectively of the intermediate room A<b>2</b>, as shown in <figref idref="DRAWINGS">FIG. 17</figref>. Accordingly, the load port <b>900</b> prevents the gas in the receiving room A<b>3</b> from entering the intermediate room A<b>2</b>. In this manner, the load port <b>900</b> increases the air tightness of the intermediate room A<b>2</b> and facilitates controlling of the pressure P<b>2</b> of the intermediate room A<b>2</b>.

0213As described above, the load port <b>900</b> according to the ninth embodiment facilitates controlling of the pressure <b>2</b> of the intermediate room A<b>2</b> while the gas replacement operation is being performed.

0214It should be noted that the setup of the ninth embodiment is applicable to the load port <b>800</b> of the eighth embodiment and provides advantages similar to the ninth embodiment.

Tenth Embodiment

0215In a load port <b>1000</b> of a tenth embodiment, the cover <b>921</b> of the ninth embodiment is modified to a cover <b>1021</b>. <figref idref="DRAWINGS">FIG. 22</figref> is a perspective view showing the load port <b>1000</b> according to the tenth embodiment. <figref idref="DRAWINGS">FIG. 23</figref> is a plan sectional view (sectional view along line <b>23</b>-<b>23</b> of <figref idref="DRAWINGS">FIG. 22</figref>) showing the load port <b>1000</b> and a wafer carrier <b>10</b> according to the tenth embodiment. The same symbols or symbols having the same symbols at the last part (last two digits) are used for components having the same functions as the ninth embodiment in describing the tenth embodiment and drawings. And the descriptions will not be repeated for these similar components.

Setup of Load Port

1000

0216As shown in <figref idref="DRAWINGS">FIGS. 22 and 23</figref>, the cover <b>1021</b> has a side wall <b>1021</b><i>a </i>further extended compared with the ninth embodiment and an additional back wall <b>1021</b><i>c. </i>

0217The back wall <b>1021</b><i>c </i>is configured to enclose a side cover member <b>1022</b> on a side closer to a receiving room A<b>3</b>. The back wall <b>1021</b><i>c </i>has an aperture <b>1021</b><i>d </i>through which wafers are conveyed.

0218As shown in <figref idref="DRAWINGS">FIG. 23</figref>, the length of a narrow passage <b>1021</b><i>b </i>is greater than that of the ninth embodiment by the extended amount of the side wall <b>1021</b><i>a </i>and the additional back wall <b>1021</b><i>c </i>enclosing the side cover member <b>1022</b>. When a gas moves inside the narrow passage <b>1021</b><i>b </i>(see an arrow D<b>1008</b>), a fluid resistance is greater than the ninth embodiment and consequently a pressure P<b>4</b> is also greater than the ninth embodiment. Accordingly, the load port <b>1000</b> increases the air tightness of an intermediate room A<b>2</b> and facilitates controlling of a pressure P<b>2</b> of the intermediate room A<b>2</b>.

0219It should be noted that it may be possible to increase the fluid resistance applied to the entering gas if the width of the narrow passage is made further smaller.

Modifications

0220The present is not restricted to the above-described embodiments; rather, various modifications or changes may be made, which are also equivalently encompassed within the scope of the present invention.

0221(1) A description has been given as shown in <figref idref="DRAWINGS">FIG. 9</figref> regarding an arrangement in which the nozzle unit <b>110</b>A can be stored within the storage portion <b>121</b>A. The present invention is not restricted to such an arrangement. Also, an arrangement may be made in which the nozzle unit <b>110</b>A is provided in a manner that allows the nozzle components thereof to be turned with the side ends of the upper portion of the door opening portion <b>202</b> serving as their turning axes. With such an arrangement, the nozzle components of the nozzle unit <b>110</b>A can be stored along the upper-portion cover member <b>123</b> such that they are stacked on one another.

0222Such an arrangement does not require any particular nozzle unit elevator mechanism in the storage portion <b>121</b>A, thereby providing a simpler mechanism of the storage portion <b>121</b>A.

0223(2) A description has been given regarding the load port <b>100</b> including the side-face cover elevator motor <b>168</b> for raising the side-face cover member <b>122</b>, and a nozzle driving motor <b>166</b> for extending the first nozzle unit <b>110</b>-<b>1</b> toward the door opening portion <b>202</b>. The present invention is not restricted to such an arrangement. An arrangement may be made which includes a cam that changes its position according to the action of raising the side-face cover member <b>122</b> from the storage portion <b>121</b>. With such an arrangement, the first nozzle unit <b>110</b>-<b>1</b> may be extended to the door opening portion <b>202</b> according to the action of the cam.

0224Such an arrangement enables both the side-face cover member <b>122</b> and the first nozzle unit <b>110</b>-<b>1</b> to be extended to the door opening portion <b>202</b> using a single motor (e.g., the side-face cover elevator motor <b>168</b>).

0225(3) A description has been given regarding an arrangement in which the control unit <b>160</b> retracts the nozzle unit <b>110</b> from the door opening portion <b>202</b> after the atmosphere of the wafer carrier <b>10</b> has been purged while maintaining the airtight space B thus formed (S<b>110</b>). The nozzle unit, e.g., the nozzle unit <b>110</b>, <b>110</b>B, <b>110</b>C, or <b>110</b>D, which has been extended to the door opening portion <b>202</b>, is located at a position outside of the course H of the outer edge of the wafer <b>1</b> which is transferred to the processing space provided within the wafer processing apparatus. Accordingly, with such an arrangement, the operation in Step S<b>110</b> may be eliminated.

0226In this case, with the load port <b>100</b>, <b>100</b>B, <b>100</b>C, or <b>100</b>D having such a configuration, the side-face cover member <b>122</b> is stored within the storage portion <b>121</b> while maintaining the state in which the nozzle unit <b>110</b>, <b>110</b>B, <b>110</b>C, or <b>110</b>D is extended to the door opening portion <b>202</b>. Such an arrangement enables the atmosphere of the wafer carrier <b>10</b> to be purged while transferring the wafer <b>1</b> toward the processing space by the wafer transfer robot of the wafer processing apparatus for performing predetermined processing. This improves the operation efficiency.

0227(4) A description has been given regarding the load port <b>100</b> employing the oxygen concentration sensor <b>164</b>. Also, other appropriate sensors such as a nitrogen sensor or the like for detecting the ratio of the purge gas, the concentration of the purge gas, etc., may be employed as long as the sensor provides an indicator that indicating the purge degree of the atmosphere of the wafer carrier <b>10</b>.

0228(5) A description has been given regarding an arrangement in which the control unit <b>160</b> switches the channel switching unit <b>163</b> according to the detection signal C detected by the oxygen concentration sensor <b>164</b>. The present invention is not restricted to such an arrangement. Also, the control unit <b>160</b> may switch the channel switching unit <b>163</b> at a predetermined timing using a timer or the like.