Method of processing an object in a container and lid opening/closing system used in the method

The present invention relates to a so-called FIMS (Front-Opening Interface Mechanical Standard) system used when a wafer internally held in a transport container called a pod is transferred between semiconductor processing devices in a semiconductor manufacturing process or the like. More specifically, in a FIMS system in which a pod called FOUP (Front-Opening Unified Pod), which is a closed container for accommodating wafers, is placed, and the lid of the pod is opened and closed to transfer the wafer to the pod. The present invention relates to a FIMS system having a purge mechanism for cleaning the inside of the pod, that is, a lid opening / closing system.

Previously, the semiconductor manufacturing process was performed in a so-called clean room in which the inside of a room for handling semiconductor wafers was highly cleaned. However, from the viewpoint of coping with the increase in wafer size and reducing the cost required for managing the clean room, in recent years, only the inside of the processing device, the pod (wafer storage container), and the minute space where the substrate is transferred from the pod to the processing device. The method of keeping the wafer in a highly clean state has been adopted.

The pod is a main body having a substantially cubic shape having a shelf capable of holding a plurality of wafers in a parallel and spaced state inside the pod, and an opening used for inserting and removing wafers on one of the surfaces constituting the outer surface, and a main body thereof. It consists of a lid that closes the opening. A pod in which the surface on which this opening is formed is not the bottom surface of the pod but is located on one side surface (the surface facing a minute space) is collectively called a FOUP (front-opening unified pod), and the present invention refers to this FOUP. The main target is the configuration to be used.

The above-mentioned minute space has an opening facing the pod opening, a door for closing the opening, a second opening provided on the semiconductor processing apparatus side, and the wafer is held by entering the inside of the pod through the opening. It also has a transfer robot that passes through the second opening and conveys the wafer to the processing apparatus side. The configuration that forms the microspace also has a mounting table that supports the pod so that the pod opening faces the front of the door.

On the upper surface of the mounting table, the pod is mounted by engaging with a positioning pin that is fitted into a positioning hole provided on the lower surface of the pod to define the mounting position of the pod and a clamped portion provided on the lower surface of the pod. A clamp unit to be fixed to is arranged. Normally, the mounting table can be moved back and forth by a predetermined distance with respect to the door direction. When transferring the wafer in the pod to the processing device, the pod is moved with the pod placed until the pod lid contacts the door, after which the door removes the lid from the pod opening. .. By these operations, the inside of the pod and the inside of the processing device are communicated with each other through a minute space, and thereafter, the wafer transfer operation is repeated. The FIMS (front-opening interface mechanical standard) system is collectively referred to as a mounting table, a door, an opening, a door opening / closing mechanism, a wall forming a part of a minute space in which the opening is formed, and the like.

Here, normally, the inside of the pod in which the wafer or the like is housed is filled with highly cleanly controlled dry nitrogen or the like to prevent pollutants, oxidizing gases, etc. from entering the inside of the pod. There is. However, when the wafer in the pod is brought into various processing devices and subjected to a predetermined process, the inside of the pod and the inside of the processing device are always maintained in a communicating state. A fan and a filter are arranged in the upper part of the room where the transfer robot is arranged, and clean air in which particles and the like are normally controlled is introduced into the room. However, when such air enters the inside of the pod, the wafer surface may be oxidized by oxygen or moisture in the air.

<patcit num="1"><text>Japanese Unexamined Patent Publication No. 11-145245</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 2003-007799</text></patcit>

<p> With the miniaturization and higher performance of semiconductor devices, oxidation by oxygen and the like that has entered the inside of the pod, which has not been a problem in the past, has begun to be noted. These oxidizing gases form an ultrathin oxide film on the wafer surface or various layers formed on the wafer. Due to the presence of such an oxide film, there is a possibility that the fine element cannot secure desired characteristics. As a countermeasure, it is conceivable to suppress the invasion of gas whose oxygen partial pressure or the like is not controlled from the outside of the pod into the inside of the pod. As a specific method, Patent Document 1 discloses a configuration in which a gas supply nozzle and a suction nozzle are provided in a region adjacent to the pod opening in the FIMS system to form an air flow film that substantially closes the pod opening. There is. The formation of the airflow film prevents external gas from entering the pod.</p><p> In the semiconductor manufacturing apparatus, a process using a gas that contaminates various wirings and the like formed on the wafer, such as an etching process, may be performed inside the processing apparatus. In this case, Patent Document 2 discloses a method of suppressing the invasion of the gas from the inside of the processing apparatus into the inside of the pod. This method also uses a fan to form an airflow film in front of the pod opening in the FIMS system to prevent the inflow of gas from the processing device into the pod. Naturally, this method is considered to be effective in suppressing the inflow of oxygen into the pod.</p><p> However, when these methods were put into practical use, it was actually confirmed that the oxygen partial pressure inside the pod increased remarkably immediately after the pod opening was opened. Therefore, these methods need to be further improved in order to meet the above requirements. In response to such a situation, the present inventor variously modifies the shape of the gas discharge nozzle used for forming the airflow membrane, and suppresses the oxygen concentration in the airflow membrane even at a position away from the nozzle. We are proposing a configuration that suppresses the intrusion of oxidizing gas into the pod. We also propose a configuration in which a purging gas is introduced into the pod at the same time as the airflow film is formed, and the oxidizing gas inside the pod is reduced. However, due to various demands such as higher performance of semiconductors and improvement of processing capacity of semiconductor manufacturing equipment, further reduction of partial pressure of oxidizing gas is desired for pods fixed to the FIMS system. In view of the above background, the present invention is a method for processing a wafer as an object to be contained, which makes it possible to suppress the partial pressure of an oxidizing gas such as oxygen inside the pod to a predetermined low level even after the pod is released. And it is an object of the present invention to provide a lid opening / closing system for a pod which is a closed container used in the method.</p>

<p> In order to solve the above problems, the method for treating an object to be contained according to the present invention is a substantially box-shaped body capable of accommodating the object to be contained and having an opening on one surface, and the main body can be separated from the main body. By removing the lid from the storage container provided with a lid that closes the opening to form a closed space together with the main body, the opening can be opened to allow the contents to be inserted and removed. A method for treating an object to be contained, which is inserted and removed to perform a predetermined process on the object to be contained outside the container, and is used for a substantially rectangular opening provided in a wall forming a minute space in which particles are controlled. The closure is placed with the openings facing each other, the lid is held by a door that substantially closes the opening, and the door holding the lid is rotated by a predetermined angle with the horizontal axis below the opening and parallel to the wall as the center of rotation. As a result, the lid is moved into the minute space to take the retracted posture, and then the door that maintains the retracted posture is driven vertically downward to open the opening, and the container is inserted and removed through the opening and the opening. The door in the retracted position is driven vertically upward to return to the stop position after rotating by a predetermined angle, and further rotated in the opposite direction by a predetermined angle to close the opening by the lid, and the door is used. A state in which a gas curtain is formed by a predetermined gas flowing in a direction from the upper side to the lower side of the opening, and the door stops rotating to maintain the retracted posture by having a step of opening the holding of the lid. The gas curtain is abutted against the lid held by the door, and a step of purging the inside of the storage container with a predetermined gas flow forming the gas curtain directed toward the inside of the storage container is further provided.</p><p> Further, in order to solve the above problems, the lid opening / closing system according to the present invention has a substantially box-shaped main body capable of accommodating an object to be contained and having an opening on one surface, and an opening separable from the main body. A lid opening / closing system that opens the opening by removing the lid from the storage container provided with a lid that closes the lid to form a closed space together with the main body, and allows the storage container to be inserted and removed. A mounting table to be mounted and a downflow in which particles are controlled via a fan filter unit placed adjacent to the mounting table and arranged at the top are formed inside, and a mechanism for transporting an object to be contained is accommodated. A substantially rectangular shape formed on a wall adjacent to the mounting table and determining a part of the minute space, and provided in an arrangement that can face the opening in the storage container mounted on the mounting table. The opening, the lid can be held and the opening can be substantially closed, and the opening is opened by holding the lid to communicate the opening with the opening, and the inside of a minute space. A purge nozzle that is arranged on both sides of the opening and is capable of supplying a predetermined gas to the inside of the storage container through the opening and the opening, and an inside of a minute space, immediately before the opening and at the opening. The inflow prevention member is arranged at the upper part of the upper side and suppresses the inflow of the downflow immediately before the opening, and the inflow prevention member is directed from the upper side of the opening to the lower side of the opening in the flow direction of the downflow. Includes a curtain nozzle capable of supplying a given gas along a direction parallel to, and the door turns a given angle around a horizontal axis below the opening and parallel to the wall when holding the lid and opening the opening. By moving, the lid is moved into a minute space, and the inflow prevention member is formed in a state where the door is rotated by a predetermined angle. It is characterized in that the predetermined gas from the curtain nozzle is supplied toward the rectangular region while covering with respect to the direction.</p>

<p> According to the present invention, a gas curtain due to an inert gas flow is formed adjacent to the opening of the pod and at a position where the opening is closed, and when purging the inside of the pod, the gas curtain also supplies purge gas to the inside of the pod. It is used as a route. Therefore, in the past, the purging operation could be performed only from the original gas supply path for purging, but an additional purging operation can be performed via a further path, and the purging operation can be speeded up or It is possible to improve the purging efficiency.</p><p> Further, according to the present invention, it is possible to maintain a high concentration of the inert gas in the inert gas stream constituting the gas curtain itself. For example, when a gas is ejected from a nozzle, it is known that the gas entrains another gas existing in the vicinity of the nozzle opening and becomes an air-fuel mixture to form a gas flow. That is, when the gas curtain is formed, the gas entrains the gas existing around the nozzle, so that the concentration of the inert gas constituting the gas curtain decreases, and the oxidizing gas may be supplied from the gas curtain to the inside of the pod. is there. Further, the gas curtain may entrain the surrounding gas, so that the concentration of the inert gas constituting the gas curtain may decrease. According to the present invention, the downflow constituting the ambient gas and the curtain nozzle or its surrounding space are separated by a curtain cover, and the gas existing in the vicinity of the nozzle opening is also regarded as a high-concentration inert gas. In addition, the curtain cover prevents downflow from flowing into the wall-lid area as the gas curtain hits the lid and heads into the pod. Therefore, it is possible to suppress the inflow or diffusion of the gas containing the oxidizing gas such as downflow into the gas curtain reaching the region, and it is possible to effectively suppress the invasion of the oxidizing gas into the inside of the pod.</p><p> Further, the formation of the gas curtain makes it possible to suppress the diffusion of the surrounding gas inside the pod. The supply of the inert gas to the inside of the pod is performed by giving a predetermined direction so as not to affect the gas curtain. That is, the gas curtain suppresses the invasion of gas from the outside of the pod into the inside of the pod, and at the same time, the concentration of the inert gas inside the pod is maintained constant by supplying the inert gas to the inside of the pod. By combining these effects, the partial pressure of the oxidizing gas inside the pod is always maintained at a predetermined low pressure even when the pod is opened. In addition, by combining these effects, a pole is compared with the case where a large amount of inert gas is required to prevent the invasion of the oxidizing gas into the pod by simply supplying the inert gas to the inside of the pod. With a small amount of inert gas, the effect of maintaining low partial pressure of oxidizing gas of equal or higher level can be obtained.</p>

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of a main part of a lid opening / closing device (FIMS, hereinafter referred to as a load port) according to the first embodiment of the present invention. When only a part of the door opening / closing mechanism, a wall forming a part of a minute space formed by an opening, an inflow prevention member newly added in the present invention, and an accompanying structure are viewed from the minute space side. It is a schematic perspective view. Further, FIG. 2A is a diagram showing a schematic configuration of a cross section of the load port and the pod in a state where the pod is placed on the load port (mounting table) and the lid of the pod is in contact with the door, and FIG. 2B is shown. Shows the cross section along the line BB in FIG. 2A as viewed from the microspace side. Although various configurations are attached to the mounting table and the like, detailed illustrations and explanations thereof are omitted here because these configurations are not directly related to the present invention.

Here, the pod mounted on the load port and the wafer housed in the pod will be described above (see FIG. 2A). A space for accommodating the wafer 1 to be processed is formed inside the main body 2a of the pod 2. The main body 2a has a substantially box-like shape having an opening on any one surface existing in the horizontal direction. Further, the pod 2 is provided with a lid 4 for sealing the opening 2b of the main body 2a. A shelf (not shown) having a plurality of stages for vertically stacking the horizontally held wafers 1 is arranged inside the main body 2a, and the intervals between the wafers 1 placed therein are fixed. It is housed inside Pod 2. Wafer 1 is used as an object to be contained in the present invention, pod 2 is used as a container, and main body 2a is used as a main body defined as having a shape substantially on a box because its basic shape is a box. Since the basic shape of the opening 2b is rectangular, it corresponds to the opening defined as a substantially rectangular shape.

The load port 51 according to the present invention comprises a mounting table 53, a door 6, an opening 10 that functions as an opening of the load port, a door opening / closing mechanism 60, and a minute space (a transport chamber 52 described later) in which the opening is formed. Includes a wall 11 as a constituent member. The mounting table 53 includes a movable plate 54 having a flat surface at the top on which the pod 2 is actually mounted and the pod on which the pod 2 is mounted can be approached or separated in the direction of the opening 10. A positioning pin 54a is embedded in the flat surface of the movable plate 54, and the positioning pin 54a is fitted into the positioning recess 2c provided on the lower surface of the pod body 2a to position the pod 2 and the movable plate 54. The relationship is uniquely determined.

The opening 10 provided in the wall 11 is large enough to fit the lid 4 that closes the pod opening 2b when the pod 2 positioned on the movable plate 54 is brought closest to the opening 10 by the plate. That is, it has a rectangular shape that is one size larger than the rectangular outer shape of the lid 4. The position where the movable plate 54 stops the pod 2 may be such that the door 6 is at a position where the lid 4 of the pod 2 can be removed from the pod body 2a. The door 6 is supported by the door opening / closing mechanism 60 via the door arm 6a. The door opening / closing mechanism 60 opens the door 6 at a position where the opening 10 is substantially closed, and the transfer mechanism (not shown) that completely opens the opening 10 of the wafer 1 with respect to the inside of the pod 2 through the opening 10. It enables movement between retractable positions that can be inserted and removed.

Further, the door opening / closing mechanism 60 is composed of a plurality of air cylinders and the like (not shown), and rotates the door 6 together with the door arm 6a around the fulcrum 61. The rotational operation is performed between the closed position of the opening 10 and the position where the door 6 takes the retracted posture when driven to the retracted position vertically below. In the retracted posture, the surface 6c of the door 6 facing the opening 10 has a distance between the surface and the plane (wall 11) on which the opening 10 is formed from the upper side to the lower side of the opening 10. It is getting smaller continuously. That is, the facing surface 6c of the door 6 facing the opening 10 is arranged with a predetermined elevation angle with respect to the surface including the wall 11 in the retracted posture. In the retracted posture, it is not preferable that the facing surface 6c is largely separated from the lower side of the opening 10 due to the purging in the pod described later. In the present invention, when the door 6 holds the lid 4, the distance between the lower side of the opening 10 and the surface of the lid 4 toward the inside of the pod in the retracted posture will be described later after considering the thickness of the lid 4. When the purge gas from the purge nozzle is supplied to the inside of the pod, the distance is maintained so that the flow of the gas does not interfere with the lid 4.

The curtain nozzle 12 is arranged in the upper part of the space immediately before the opening 10 (the upper part of the upper side of the first opening). The curtain nozzle 12 is arranged to form a downflow gas curtain immediately before the opening 10 on the microspace 52 side. In the present embodiment, the curtain nozzle 12 has a rectangular parallelepiped shape, and a plurality of nozzle openings 12b are formed on the lower surface 12a facing the space immediately before the opening 10. Further, a purge nozzle 21 for supplying purge gas for purging the inside of the pod 2 is also arranged on the microspace 52 side of the opening 10 and outside of both sides thereof. The purge nozzle 21 has a tubular purge nozzle body 21a extending in one direction and is connected to a purge gas supply system (not shown). The purge nozzle main body 21a is arranged as a pair so as to be adjacent to the outside of the opening on both sides of the load port opening 10 and extend parallel to the side.

FIG. 3 shows a schematic configuration of the purge nozzle main body 21a, the pod 2, and the wafer 1 when viewed from above. A plurality of purge nozzle openings 21b are arranged in the purge nozzle main body 21a at equal intervals in the extending direction so as to coincide with the accommodation interval of the wafers 1 in the pod 2 and to coincide with the space between the respective wafers 1. Is preferable. Further, the purge nozzle opening 21b is also formed so as to face the central portion of the wafer 1. That is, the direction of gas supply from the purge nozzle is a direction in which the gas is supplied in parallel with a plane extending perpendicularly to the gas supply direction from the curtain nozzle and toward a point in the plane at an equal distance from both purge nozzles. It is preferable to have.

By setting the direction perpendicular to the flow direction of the curtain gas, it is possible to reliably supply the purge gas to the inside of the pod 2. Here, it is most effective to eject the purge gas so that the purge gas is directed toward the wafer surface. However, since the interval between the wafers 1 is narrow inside the pod 2, the gas is supplied parallel to the wafer surface. It is supposed to be. Although the purge nozzle 21 and the curtain nozzle 12 described above are actually connected to a gas supply system (not shown), they are omitted in the drawing notes to facilitate understanding of the configuration of the present invention. Has been done. Further, since this gas supply system is a general one composed of a gas source, a regulator, etc., the description here will be omitted.

Next, the operation of the configuration when the wafer 1 is actually inserted and removed from the pod 2 will be described. When the pod 2 is placed on the mounting table 53, the door 6 substantially closes the opening 10. In the present embodiment, the door 6 has a size that forms a gap that allows the minute space 52 and the external space to communicate with each other when the door 6 is in a position where the opening 10 is closed. Therefore, in this embodiment, the door 6 can only substantially close the opening 10. After the pod 2 is placed, the movable plate 54 moves in the direction of the opening 10 and stops at a position where the lid 4 comes into contact with the door 6. The door 6 holds the lid 4 by an engagement mechanism (not shown). Here, the formation of the downflow in the minute space 52 by the fan filter unit 63 and the formation of the gas curtain immediately before the opening 10 by the gas supply from the curtain nozzle 12 are always performed even before the pod 2 is placed. It is done.

Subsequently, the door opening / closing mechanism 60 rotates the door arm 6a around the fulcrum 61, causes the door 6 to take the retracted posture shown in FIG. 4A, and partially opens the pod 2 with respect to the minute space 52. Note that FIG. 4A and FIG. 4B, which will be described later, show a state in which the periphery of the opening 10 is viewed from the side in the same manner as in FIG. 2A. As described above, in the retracted posture, the lower end of the lid 4 held by the door 6 is in a state where the opening 10 is almost closed, and the upper end of the lid 4 is in a state where a predetermined distance is maintained from the opening 10. It is in. The gap formed by the lid 4 opening upward away from the opening 10 is within the formation range of the nozzle opening 12b of the curtain nozzle 12. From this point, the supply of purge gas from the purge nozzle 21 is started. The door opening / closing mechanism 60 retracts the door 6 to the retracted position, which is the lowermost end of the drive range, while maintaining this retracted posture with respect to the door 6. FIG. 4B shows a state in which the door 6 is arranged in the retracted position. In this state, the opening 2b of the pod 2 is opened, and the wafer 1 can be transferred to the inside of the pod 2 by a transfer mechanism (not shown) arranged in the minute space 52.

FIG. 4C shows a schematic configuration of the opening 10 viewed from the microspace 52 side in the same manner as in FIG. 2B. A gas similar to the purge gas is supplied from the curtain nozzle 12 so as to form a downflow parallel to the wall 11. Further, the purge gas is supplied from each of the pair of purge nozzles 21 so that the flow of the purge gas is directed to the central portion of the wafer 1 housed inside the pod 2. In this state, the wafer 1 is conveyed. During the transfer operation, the purging operation for the inside of the pod 2 is continuously performed to keep the partial pressure of the oxidizing gas inside the pod low. After the loading operation of the wafer 1 to be accommodated inside the pod 2 is completed, the following closing operation of the lid 4 is performed.

In the closing operation, the door opening / closing mechanism 60 raises the door 6 and returns the door 6 to the position where the door 6 shown in FIG. 4A stops rotating and takes the retracted posture. In this state, the door opening / closing mechanism 60 temporarily stops operating, and the door 6 is maintained in the posture before rotation. At that time, the lid 4 held by the door 6 is positioned at a certain angle with respect to the gas curtain, and the gas flow direction is changed from downward to the inside of the pod. In the retracted posture, as described above, only the lower end of the lid 4 is in a state in which the opening 10 is substantially closed, so that the curtain gas supplied toward the gap formed in the upper end of the lid is the same. Most will be sent to the inside of Pod 2.

As a result, the total amount of purge gas supplied toward the inside of the pod immediately before the pod is closed by the lid can be significantly increased as compared with the total amount of purge gas supplied only by the normal purge nozzle. After maintaining the state shown in FIG. 4A for a predetermined time and sufficiently purging the inside of the pod 2 to sufficiently reduce the abundance of oxidizing gas in the space, the door opening / closing mechanism 60 rotates the door 6. , Close the pod opening 2a with the lid 4. By the above operation, the wafer 1 can be enclosed in the pod 2 at a low oxidizing gas concentration which cannot be obtained by the conventional configuration.

In the above-described operation, the door 6 is retracted from the start to the end of the insertion / removal of all the wafers when the wafer insertion / removal operation is being performed. However, in the case of only the purge gas supplied from the purge nozzle, if the opening time of the pod 2 is long, it is considered that the partial pressure of the oxidizing gas inside the pod 2 gradually increases due to the diffusion of the atmosphere from the microspace 52. Be done. In such a case, each time one wafer 1 is inserted or removed, the door 6 is raised from the retracted position to maintain the state shown in FIG. 4A in which the purging efficiency is increased. Alternatively, it is desirable to add an action of closing the pod once after the state. This makes it possible to more effectively suppress the increase in the partial pressure of the oxidizing gas.

In the above-described embodiment, the gas curtain is always formed from the viewpoint of effectively suppressing the partial pressure of the oxidizing gas inside the pod. However, from the viewpoint of reducing the amount of purge gas used and reducing the cost, it is preferable to minimize the formation of the gas curtain. Here, in inserting and removing the wafer from the pod, it can be said that it is only necessary to reduce the partial pressure of the oxidizing gas inside the pod when the pod is closed. The purging method in this case will be described below. FIG. 5A is a flowchart showing the operation of removing the lid 4 from the pod 2 and starting the insertion / removal of the wafer 1. FIG. 5B is an operation of attaching the lid 4 to the pod 2 after the insertion / removal of the wafer 1 with respect to the pod 2 is completed. It is a flowchart which shows.

As shown in FIG. 5A, the placement of the pod 2 in step 1, the engagement between the lid 4 and the door 6 by the movement of the movable plate 54 described later in step 2, and the lid 4 from the pod 2 by the door 6 in step 3. Wafer mapping in the pod 2 is performed by a mapping mechanism (not shown) that is performed at the same time as the separation operation and the movement to the retracted position after taking the retracted posture of the door 6 in step 4. In step 5, the stop at the retracted position of the door 6 is detected by a door lower end sensor (not shown). In step 6, the supply of purge gas from the purge nozzle 21 is started according to the detection result. By the end of the series of operations, it is confirmed that the so-called loading operation of the pod 2 is completed, and the wafer 1 is taken out and inserted from the pod 2. The supply of the purge gas started in step 6 is continued throughout the insertion / removal operation of the wafer 1.

FIG. 5B shows the so-called unload operation of the pod 2. First, in step 11, the insertion / removal operation of the wafer 1 is completed, and an instruction to start the unloading operation is issued. In the present embodiment, the supply of the purge gas is temporarily stopped in step 12 in order to suppress the generation of particles and the like due to the purge gas being sprayed on the moving configuration of the door and the like. Subsequently, the ascending operation of the door 6 in step 13 is performed, and it is detected in step 14 that the door 6 has reached the ascending end (the position in which the door 6 takes the retracted posture after rotation). In step 15, the supply of the purge gas from the purge nozzle 21 and the supply of the curtain gas from the curtain nozzle 12 are started at the same time according to the detection result. As described above, the curtain gas abuts on the lid 4 and its flow direction is directed to the inside of the pod 2, and both the purge gas and the curtain gas are supplied to the inside of the pod.

This state is maintained until it is detected in step 16 that the predetermined time has elapsed. After a lapse of a predetermined time, the supply of these gases is stopped in step 17, and in the following step 18, the operation of attaching the lid 4 to the pod 2 by the door 6 is performed. After the lid 4 is fixed to the pod body 2a, the movable plate 54 is retracted in step 19, and the end of the so-called unloading operation of the pod 2 is confirmed in step 20. In the above unloading operation, just before the lid is closed, only the purge gas originally supplied from the purge nozzle is used for purging, but the curtain gas (the same gas as the purge gas) is additionally supplied from the curtain nozzle. Nozzle. Therefore, it is possible to supply a large amount of purge gas, which was not possible with the conventional configuration, in a short time, and it is possible to effectively suppress the partial pressure of the oxidizing gas inside the pod and close the pod.

In the above embodiment, the curtain nozzle 12 has a rectangular parallelepiped shape and gas ejection holes are provided in the entire lower surface thereof. However, the shape, arrangement, number, etc. of the ejection holes are the flow rate of the supplied gas and the number of the ejection holes. It is desirable that the lid 4 and the opening 10 be appropriately changed according to the distance between the upper sides of the lid 4 and the opening 10 in the retracted posture described later. In this case, it is preferable to appropriately change the shape, arrangement, etc. of the opening 21b for gas ejection in the purge nozzle 21 as well. Further, although the door 6 is supposed to substantially close the opening 10, it may be configured to completely close the opening 10.

Here, when a gas flow such as purge gas is present, the gas existing around the flow is also involved to some extent by the flow, and the purity of the gas is gradually lowered from the peripheral portion. In view of such a phenomenon, in the above-described embodiment, the forming range of the nozzle opening 12b for forming the gas curtain provided in the curtain nozzle 12 is stopped by the door 6 rotating from the closed position of the opening 10. It is set to be wider on the microspace 52 side than the rectangular area formed between the upper side of the opening 10 and the upper side of the lid 4 held by the door 6 in the retracted posture. As a result, even when gas is entrained from the downflow in which the gas curtain is formed in the minute space 52, the curtain gas containing the entrained gas is between the opening 10 and the lid 4. It is supposed to suppress the flow.

Further, when trying to supply a purge gas such as an inert gas from a purge nozzle or the like, it is conceivable that the purge gas ejected from the nozzle hole entrains the gas existing around the hole, and the purity of the purge gas is lowered due to the mixing of the gas. Further, a further configuration example for carrying out the present invention in consideration of suppressing the entrainment of gas around the nozzle hole will be described below with reference to the drawings. FIG. 6 is a side view showing the main part in an enlarged manner in the same manner as in FIG. 2A. In the figure, the same reference numbers will be added to the configurations showing the same effects as those shown in FIG. 2, and the description thereof will be omitted.

In this embodiment, a curtain cover 23 that covers the upper surface of the upper surface of the curtain nozzle 12 and extends further to the minute space side of the end surface 12c on the minute space 52 side is arranged. The curtain cover 23 has an L-shaped cross section that covers the rectangular parallelepiped curtain nozzle 12, and the vertical surface 23a facing the end surface 12c of the curtain nozzle 12 is an upper body in which the door 6 is in a retracted posture. It is stretched to almost the same height in the vertical direction as the side located at the top of the door. By arranging the curtain cover 23, the surrounding gas (gas controlled only by the particles supplied by the downflow) is not always supplied to the vicinity of the nozzle. In addition, by extending below the vertical surface 23a, the entrainment of downflow in the gas curtain is suppressed. Therefore, it is possible to maintain the purity of the curtain gas from the curtain nozzle 12 to the lid 4 to a higher purity as compared with the configuration of the above embodiment.

FIG. 7 shows a further modification of the form shown in FIG. 6 in the same manner as in FIG. Similar to the form shown in FIG. 6, the same reference numbers will be added to the configurations that exhibit the same effects as the individual configurations, and the description thereof will be omitted. In this embodiment, the length of the side of the curtain nozzle 12 along the driving direction of the pod 2 is shortened so that the nozzle opening 12b is formed in the upper side of the opening 10 with the door 6 in the retracted posture. It is smaller than the rectangular area formed between the upper side of the lid 4 held by the door 6. With this configuration, the thickness of the gas curtain is reduced. As a result, the flow velocity of the curtain gas can be increased without increasing the flow rate of the purge gas used for the curtain gas, and the curtain gas can be supplied to the depth of the pod 2. For example, it is conceivable to send the gas supplied from the purge nozzle to the region on the relatively open side of the pod 2 and send the curtain gas to the inner region to purge the inside of the pod with a small flow rate.

In this case, the necessity of suppressing the entrainment of the ambient atmosphere at the nozzle opening described above and the entrainment of the ambient gas due to the curtain gas flow becomes higher than that of the above-described configuration. Therefore, a space formed between the curtain nozzle 12 and the rectangular region formed between the upper side of the opening 10 (the side surface of the minute space of the wall 11) and the upper side of the lid 4 held by the door 6 is formed. , Need to be effectively covered by the curtain cover 23. In this embodiment, the width of the horizontal plane 23b of the curtain cover 23 (the length from the side connecting with the wall 11 to the opposite side thereof) is substantially equal to the length of the corresponding width of the curtain nozzle 12, and is equal to the vertical plane. An inclined surface 23c is arranged at the connecting portion of the door 6 to reduce the space, and the vertical surface 23a extends downward on the minute space side of the side located at the top of the door 6. By forming the curtain cover 23 in this shape, it is possible to suppress the entrainment of the atmosphere from the downflow in the minute space even when the curtain nozzle 12 is made smaller.

Both the curtain nozzle 12 and the curtain cover 23 described above are the above-mentioned rectangular region and the fan filter unit formed as two sides facing the wall 11 and the lid 4 with respect to the flow direction of the downflow formed in the minute space. It is placed between and. The curtain nozzle 12 and the curtain cover 23 act as inflow prevention members that suppress or prevent the air supplied from the fan filter unit into the minute space from reaching the rectangular region due to the downflow. In order to achieve the purpose, when the inflow prevention member is configured by the curtain nozzle alone, the shape of the curtain nozzle is made larger than the shape of the rectangular region to ensure the effect of covering the rectangular region. Needs. In this case, it is preferable that the nozzle opening forming region is equal to or larger than the rectangular region as described above. When the shape of the curtain nozzle is smaller than the shape of the rectangular region, it is preferable to arrange a curtain cover to cover the rectangular region. Further, as the shape of the curtain cover, it is preferable to further arrange the above-mentioned vertical plane in order to obtain the effect of rectifying both the downflow from the fan filter unit and the gas curtain.

Next, the FIMS system, which is an actual lid opening / closing system in which the present invention is carried out, and a semiconductor wafer processing apparatus using the system will be described. FIG. 8 is a diagram showing a schematic configuration of a semiconductor wafer processing apparatus 50 corresponding to a so-called mini-environment system. The semiconductor wafer processing apparatus 50 is mainly composed of a load port portion (FIMS system, lid opening / closing device) 51, a transport chamber (microspace) 52, and a processing chamber 59. Each joint is partitioned by a partition 55a and a cover 58a on the load port side and a partition 55b and a cover 58b on the processing chamber side. In the transport chamber 52 of the semiconductor wafer processing apparatus 50, in order to discharge dust and maintain high cleanliness, an air flow (downflow) is flowed from above to below of the transport chamber 52 by a fan filter unit 63 provided above the transport chamber 52. It is occurring. Further, a downflow discharge path is provided on the lower surface of the transport chamber 52. With the above configuration, the dust is always discharged downward.

On the load port portion 51, a pod 2 which is a storage container for a silicon wafer or the like (hereinafter, simply referred to as a wafer) is installed on a mounting table 53. As described above, the inside of the transfer chamber 52 is maintained in high cleanliness for processing the wafer 1, and further, a robot arm 55 capable of actually holding the wafer in the transfer mechanism is provided inside the transfer chamber 52. Has been done. The robot arm 55 transfers the wafer between the inside of the pod 2 and the inside of the processing chamber 59. The processing chamber 59 usually includes various mechanisms for forming a thin film, processing a thin film, etc. on the surface of the wafer, but these configurations are not directly related to the present invention. The description is omitted.

As described above, the pod 2 has a space for accommodating the wafer 1 to be processed, and has a box-shaped main body 2a having an opening on one side thereof, and a lid 4 for sealing the opening. It has. Inside the main body 2a, shelves having a plurality of stages for stacking the wafers 1 in one direction are arranged, and each of the wafers 1 placed therein is housed inside the pod 2 at a constant interval. In the example shown here, the direction in which the wafers 1 are stacked is the vertical direction. An opening 10 and the above-mentioned inflow prevention member are provided on the load port portion 51 side of the transport chamber 52. The opening 10 is arranged at a position facing the opening of the pod 2 when the pod 2 is arranged on the load port portion 51 so as to be close to the opening 10. The main configurations of the curtain nozzle 12, the door 6, and the like according to the present invention are omitted here from the viewpoint of being described in the above embodiment and facilitating the understanding of the drawings. ..

9A and 9B show an enlarged side sectional view of the door 6 and the door opening / closing mechanism 60 in the device and a front view of the door 6 and the door opening / closing mechanism 60 as viewed from the side of the transport chamber 52, respectively. FIG. 9C shows an outline of the side cross section of the state in which the lid 4 is removed from the pod 2 using the door opening / closing mechanism 60. A fixing member 46 is attached to the door 6, and the door 6 is rotatably connected to one end of the door arm 6a via the fixing member 46. The other end of the door arm 6a is rotatably supported with respect to the tip of the rod 37, which is a part of the air-driven cylinder 57, via the pivot 40.

A through hole is provided between the one end and the other end of the door arm 42. A fulcrum 61 is configured by a pin (not shown) penetrating the hole and the hole of the fixing member 39 fixed to the support member 60 of the movable portion 56 that raises and lowers the structure for opening and closing the door such as the door arm 42. There is. Therefore, the door arm 42 can rotate about the fulcrum 61 according to the expansion and contraction of the rod 37 driven by the cylinder 57. The fulcrum 61 of the door arm 42 is fixed to a support member 60 provided on the movable portion 56 that can be raised and lowered.

When processing the wafer 1 with these configurations, first, the wafer 1 is arranged on the mounting table 53 so as to be close to the transfer chamber opening 10, and the lid 4 is held by the door 6. An engaging mechanism (not shown) is arranged on the surface of the door 6, and an engaged mechanism (not shown) is arranged on the surface of the lid 4, so that the surfaces of the lid 4 and the door 6 come into contact with each other. By operating these mechanisms in this state, the lid 4 is held by the door 6. Here, when the rod of the cylinder 57 is retracted, the door arm 42 operates so as to be centered on the fulcrum 61 and the door 6 is separated from the opening 10. By this operation, the door 6 rotates together with the lid 4 to remove the lid 4 from the pod 2. The state is shown in Figure 9C. After that, the movable portion 56 is lowered to convey the lid 4 to a predetermined retreat position. Since the migration operation has been described in the above-described embodiment, the description here will be omitted.

In this embodiment, FOUP and FIMS are described, but the application examples of the present invention are not limited to these. The lid opening / closing device according to the present invention is applied to a front-open type container for accommodating a plurality of objects to be held inside and a system for opening and closing the lid of the container to insert / remove the objects to be held from the container. However, it is possible to maintain the partial pressure of the oxidizing atmosphere inside the container at a low pressure. Further, when the gas filling the inside of the container is not an inert gas but a specific gas having desired characteristics, the lid opening / closing system according to the present invention is used to divide the pressure of the specific gas inside the container. It is also possible to maintain a high level.

According to the present invention, when purging the inside of a pod, not only the purge gas can be supplied from the conventional purge nozzle but also the purge gas can be supplied from a direction different from that of the purge nozzle by using a gas curtain. Oxidizing the gas inside the pod by supplying purge gas toward the wafer separately from suppressing the ingress of air into the pod from the microspace side by the gas curtain, and also using the curtain gas for purging when the pod is closed. It is possible to effectively suppress the increase in the partial pressure of the gas. Further, the present invention can be implemented only by adding a curtain nozzle, a purge nozzle, etc. to an existing FIMS system, and can be inexpensively and easily attached to a standardized system.

<figref num="1">It is a perspective view which shows the schematic structure in the main part of the lid opening / closing system which concerns on one Embodiment of this invention.</figref><figref num="2A">FIG. 6 is a diagram showing a schematic configuration of a cut surface perpendicular to a pod opening with respect to a lid opening / closing system according to an embodiment of the present invention shown in FIG. 1, that is, a load port, a pod, a lid for a pod, and a part of an opener. is there.</figref><figref num="2B">It is a figure which shows the state which the opening 10 shown in FIG. 1 is seen from the direction of arrow 2B.</figref><figref num="3">It is a figure explaining the supply direction of the purge gas supplied from a purge nozzle toward the inside of a pod.</figref><figref num="4A">It is a figure which shows one stage of the operation of opening and closing a lid in the lid opening and closing system shown in FIG.</figref><figref num="4B">It is a figure which shows one stage of the operation of opening and closing a lid in the lid opening and closing system shown in FIG.</figref><figref num="4C">FIG. 5 is a diagram showing a state in which the opening 10 is viewed in the same manner as in FIG. 2B in the state shown in FIG. 4B.</figref><figref num="5A">It is a flowchart which shows the operation procedure at the time of loading a pod to the lid opening / closing mechanism which concerns on this invention.</figref><figref num="5B">It is a flowchart which shows the operation procedure at the time of unloading the pod to the lid opening / closing mechanism which concerns on this invention.</figref><figref num="6">It is a figure which shows the further form of the lid opening / closing system which concerns on this invention.</figref><figref num="7">It is a figure which shows the further form of the lid opening / closing system which concerns on this invention.</figref><figref num="8">It is an overall side view which shows the schematic structure of the general semiconductor wafer processing apparatus to which this invention is applied.</figref><figref num="9A">FIG. 5 is an enlarged view of a configuration of a door opening / closing mechanism and its vicinity in the device shown in FIG. 8 and shows a schematic configuration of a state in which this is viewed from the side.</figref><figref num="9B">It is a figure which shows the schematic structure when the structure shown in FIG. 9A is seen from the transport room side.</figref><figref num="9C">FIG. 9A is a diagram showing a state in which the door has the lid removed from the pod in the same manner as in FIG. 9A.</figref>

Code description

1: Wafer, 2: Pod, 4: Lid, 6: Door, 10: Opening, 11: Wall 12: Curtain nozzle, 13: Gas introduction path, 14: Gas curtain, 21: Purge nozzle, 23: Curtain cover, 37 : Rod, 39: Fixing member, 40: Axis, 46: Fixing member, 50: Semiconductor processing device, 51: Load port, 52: Transport chamber (small space), 53: Mounting table, 54: Movable plate, 55: Robot Arm, 57: Cylinder, 60: Door opening / closing mechanism, 61: Support point