Process liquid feed nozzle and process liquid feeder, and method for washing nozzle

[0001] [Technical field to which the invention belongs] The present invention relates to a treatment liquid supply nozzle for supplying a treatment liquid on a substrate such as a semiconductor wafer, a treatment liquid supply device, and a nozzle cleaning method, and supplies, for example, a coating liquid for forming an interlayer insulating film on a wafer surface. The present invention relates to a treatment liquid supply nozzle, a treatment liquid supply device, and a nozzle cleaning method. [0002] [Conventional technology] In the process of a semiconductor device, an interlayer insulating film is formed by, for example, an SOD (Spin On Dielectric) system. In this SOD system, a coating material is spin-coated on a semiconductor wafer (hereinafter referred to as a wafer) and subjected to physical treatment such as heating or chemical treatment to form an interlayer insulating film. For example, when forming an interlayer insulating film of a siloxane-based polymer or an organic polymer, a material diluted with an organic solvent is discharged onto a wafer and coated with a spin coater. Next, heat treatment or the like is carried out step by step in an environment according to the purpose. Further, depending on the material, it is necessary to add a chemical treatment such as an ammonia atmosphere treatment or a solvent replacement treatment after coating. [0003] As described above, in the step of supplying the treatment liquid onto the wafer, for example, the spin coating method is used as in the technique of applying the resist liquid on the wafer. In such a spin coating method, for example, a wafer is placed on a spin chuck in a cup and rotated, and a coating liquid is supplied from a processing liquid supply nozzle to the center of rotation of the wafer to uniformly spread the entire surface of the wafer. The treatment liquid supply nozzle of the treatment liquid supply device used in such a spin coating step has, for example, a discharge port for discharging the treatment liquid toward the wafer surface at the lower end thereof, and the upper end thereof is gripped by a moving mechanism. There is. The processing liquid supply nozzle is configured to move between the center of rotation of the wafer in the cup and the drain cup arranged outside the cup by this moving mechanism. [0004] By the way, when the treatment liquid is supplied to the wafer surface, the treatment liquid remains and adheres to the tip of the treatment liquid supply nozzle, and the treatment liquid adhered to the tip of the treatment liquid supply nozzle is a liquid that concentrates with the passage of time. Alternatively, it changes to a solidified product. These concentrated liquids and coagulated products fall on the wafer while the processing liquid is being supplied to the wafer, which causes uneven coating and film thickness fluctuation. [0005] In order to solve this problem, the applicant of the present application proposes a treatment liquid supply nozzle and a treatment liquid supply device in Japanese Patent Application Laid-Open No. 2001-38272 (Patent Document 1). The proposed treatment liquid supply nozzle and treatment liquid supply device will be described with reference to FIG. 7. In FIG. 7, reference numeral 51 is a treatment liquid supply nozzle 51 for discharging a coating liquid (treatment liquid) forming an insulating film on the wafer surface, and the treatment liquid supply nozzle 51 is fixed to the nozzle holder 50. There is. Further, the processing liquid supply nozzle 51 is composed of a large-diameter pipe 52 and a small-diameter pipe 54 inserted and arranged inside the large-diameter pipe 52. The discharge port 55 at the tip of the small diameter pipe 54 is configured to protrude downward from the discharge port 53 formed at the tip of the large diameter pipe 52. Further, a holding member 60 for holding the small diameter pipe 54 with respect to the large diameter pipe 52 is provided between the large diameter pipe 52 and the small diameter pipe 54 in the vicinity of the discharge port 53. The holding member 60 fixes the small diameter pipe 54 to the large diameter pipe 52 as described above, but is provided with a plurality of holes (not shown) so as not to obstruct the flow of the cleaning liquid described later. .. [0006] On the other hand, reference numeral 56 in the drawing is a tank for storing the coating liquid (treatment liquid) to be coated on the wafer, so that the coating liquid in the tank 56 is supplied to the small diameter tube 54 via the pump 57. It is configured. Further, reference numeral 58 in the figure is a tank 58 for storing a cleaning liquid for cleaning the vicinity of the tip of the small diameter pipe 54, and the cleaning liquid (treatment liquid) in the tank 58 via the pump 59 is a large diameter pipe 52. It is configured to be supplied to. [0007] In the processing liquid supply device configured in this way, the coating liquid in the tank 56 is supplied to the small diameter pipe 54 by the pump 57, and is applied to the wafer surface from the discharge port 55. After the coating is completed, the treatment liquid supply nozzle 51 moves on the drain cup (not shown) with the movement of the nozzle holder 50, and discharges the coating liquid (treatment liquid) remaining in the small diameter pipe 54 into the drain cup. .. Here, as described above, the coating liquid remains and adheres to the periphery of the tip of the small-diameter tube 54, particularly to the outer peripheral surface of the tip. Therefore, the cleaning liquid in the tank 58 is supplied to the large-diameter pipe 52 by the pump 59, and the cleaning liquid is made to crawl down on the outer peripheral surface of the small-diameter pipe 54. By the flow of this cleaning liquid, the coating liquid (treatment liquid) adhering to the outer peripheral surface of the tip portion of the small diameter tube 54 is washed away and washed. [0008] [Patent Document 1] Japanese Unexamined Patent Publication No. 2001-38272 (Page 5, right column, line 29 to page 6, left column, line 2, Fig. 7) [0009] [Problems to be Solved by the Invention] As described above, in the treatment liquid supply device described in Japanese Patent Application Laid-Open No. 2001-38272, the tip of the small-diameter pipe 54 is cleaned, and the cleaning liquid is supplied into the large-diameter pipe 52 to supply the cleaning liquid to the tip of the small-diameter pipe 54. This is done by letting the cleaning liquid crawl on the outer peripheral surface and let it flow down. At this time, there is a technical problem that the cleaning liquid flows down a part of the outer peripheral surface of the small diameter pipe 54 and does not flow down evenly on the entire outer peripheral surface of the small diameter pipe 54. More specifically, when the cleaning liquid comes into contact with the outer peripheral surface of the small-diameter pipe 54 and a stream of cleaning liquid is formed on the outer peripheral surface, the subsequently supplied cleaning liquid flows down one line on the outer peripheral surface. To do. As a result, there is a technical problem that the entire outer peripheral surface of the small-diameter pipe 54 does not flow down evenly, a portion is not cleaned with the cleaning liquid, and the coating liquid (treatment liquid) remains in such a portion. As described above, the coating liquid remaining on the tip (outer peripheral surface) of the small-diameter pipe 54 cannot be completely cleaned, and the coating unevenness and the film thickness fluctuate due to the treatment liquid adhering to the treatment liquid supply nozzle described above. Etc. could not be suppressed. [0010] The present invention has been made to solve the above-mentioned technical problems, and it is possible to evenly clean the entire outer peripheral surface of the nozzle when cleaning the treatment liquid supply nozzle, and the treatment liquid remaining on the outer peripheral surface of the nozzle can be cleaned. It is an object of the present invention to provide a treatment liquid supply nozzle, a treatment liquid supply device, and a nozzle cleaning method that can be washed away. [0011] [Means for solving problems] The treatment liquid supply nozzle made to achieve the above object is formed to have a diameter larger than that of a nozzle having a first discharge port for discharging the treatment liquid and a first discharge port of the nozzle, and the nozzle is formed. A nozzle holder having a second discharge port that can be inserted, and a space formed between the inner peripheral surface of the nozzle holder and the outer peripheral surface of the nozzle and connected to the second discharge port, at least to which a cleaning liquid is supplied. The processing liquid supply nozzle provided, the nozzle holder or the nozzle is configured to be movable up and down, the first discharge port of the nozzle protrudes from the second discharge port, and the treatment liquid is provided from the first discharge port. It is characterized in that the nozzle is housed in the nozzle holder and the nozzle is washed with the cleaning liquid, and a spiral groove is formed on the inner surface of the nozzle holder.<u style="single">There is.</u><u style="single">in this way,</u>When cleaning the nozzle, the entire nozzle is covered with the nozzle holder, and the cleaning liquid is allowed to flow in the space formed between the outer peripheral surface of the nozzle and the inner peripheral surface of the nozzle holder, so that the outer peripheral surface of the nozzle, particularly the tip of the nozzle, can be evenly cleaned. .. Further, when the spiral groove is formed on the inner surface of the nozzle holder, the cleaning liquid flows down as a rotating flow, the cleaning effect of the outer peripheral surface of the nozzle is increased, and the nozzle cleaning can be performed more effectively.<u style="single">To.</u>[0012] Here, it is desirable to supply a cleaning liquid and a gas into the space to clean the outer peripheral surface of the tip of the nozzle while the entire nozzle is housed in the nozzle holder. In this way, when the cleaning liquid and gas are supplied, the gas is mixed in the cleaning liquid, and in addition to the cleaning effect of the cleaning liquid itself, the cleaning effect of gas bubbles can be obtained, and the gas adheres to the entire outer peripheral surface of the nozzle more reliably. The treated liquid can be washed. [0013] Further, it is desirable to supply gas into the space and dry the outer peripheral surface of the nozzle while the entire nozzle is housed in the nozzle holder. [0014] Further, the processing liquid supply device made to achieve the above object is formed with a nozzle provided with a first discharge port for discharging the processing liquid and a diameter larger than that of the first discharge port of the nozzle. A space formed between a nozzle holder having a second discharge port through which a nozzle can be inserted and an inner peripheral surface of the nozzle holder and an outer peripheral surface of the nozzle and connected to the second discharge port, at least to which a cleaning liquid is supplied. The nozzle holder or the nozzle is configured to be movable up and down, the first discharge port of the nozzle protrudes from the second discharge port, and the processing liquid is discharged from the first discharge port. A treatment liquid supply device including a treatment liquid supply nozzle configured such that the entire nozzle is housed in the nozzle holder and the nozzle is washed with the cleaning liquid, and the first discharge port of the nozzle. A treatment liquid supply means for supplying the treatment liquid to the nozzle holder and a cleaning liquid supply means for supplying the cleaning liquid into the space are provided, and a spiral groove is formed on the inner surface of the nozzle holder.<u style="single">There is.</u><u style="single">in this way,</u>When cleaning the nozzle, the entire nozzle is housed in the nozzle holder, and the cleaning liquid is allowed to flow in the space formed between the outer peripheral surface of the nozzle and the inner peripheral surface of the nozzle holder, so that the outer peripheral surface of the nozzle can be cleaned evenly and more reliably. .. Further, when the spiral groove is formed on the inner surface of the nozzle holder, the cleaning liquid flows down as a rotating flow, the cleaning effect of the outer peripheral surface of the nozzle is increased, and the nozzle cleaning can be performed more effectively.<u style="single">it can.</u>[0015] Here, it is desirable to provide a gas supply means for supplying gas into the space. Since the gas supply means is provided in this way, gas can be supplied to the space together with the cleaning liquid at the time of cleaning, and the cleaning effect can be improved. Further, by supplying gas to the space after cleaning, the drying of the outer peripheral surface of the nozzle can be accelerated. [0017] Further, the nozzle cleaning method used to achieve the above object is a nozzle cleaning method for cleaning the treatment liquid adhering to the outer peripheral surface of the treatment liquid supply nozzle that discharges and supplies the treatment liquid. By supplying and storing the cleaning liquid in the step of accommodating the nozzle and the space formed between the outer peripheral surface of the nozzle and the inner peripheral surface of the nozzle holder, the treatment liquid adhering to the outer peripheral surface of the nozzle is cleaned and the cleaning liquid is cleaned. At least includes the step of discharging from the discharge port.<u style="single">, A spiral groove is formed on the inner surface of the nozzle holder, and the cleaning liquid is discharged from the discharge port while swirling the outer peripheral surface of the nozzle along the spiral groove.</u>It is characterized by that. In this way, since the cleaning liquid is supplied and stored in the space formed between the outer peripheral surface of the nozzle and the inner peripheral surface of the nozzle holder, the treatment liquid adhering to the outer peripheral surface of the nozzle can be more reliably cleaned. In particular, the treatment liquid adhering to the end face of the nozzle tip can also be cleaned. [0018]<u style="single">in particular,</u>A spiral groove is formed on the inner surface of the nozzle holder, and the cleaning liquid is discharged from the discharge port while swirling the outer peripheral surface of the nozzle along the spiral groove.<u style="single">Therefore, the cleaning liquid flows down as a rotating flow, the cleaning effect of the outer peripheral surface of the nozzle is increased, and the nozzle cleaning can be performed more effectively.</u> Further, when supplying the cleaning liquid to the space formed between the outer peripheral surface of the nozzle and the inner peripheral surface of the nozzle holder, it is desirable to supply gas to the space to clean the treatment liquid adhering to the outer peripheral surface of the nozzle. ..<u style="single">In addition</u>After the step of cleaning the treatment liquid adhering to the outer peripheral surface of the nozzle with the cleaning liquid, the cleaning liquid adhering to the outer peripheral surface of the nozzle is removed by supplying gas to the space between the outer peripheral surface of the nozzle and the inner peripheral surface of the nozzle holder. It is desirable to dry it. [0019] BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the treatment liquid supply nozzle, the treatment liquid supply device, and the nozzle cleaning method according to the present invention will be described based on one embodiment shown in FIGS. 1 to 3. Note that FIG. 1 is a plan view showing a schematic configuration of an SOD coating processing unit (processing liquid supply device) in the SOD system described above, and FIG. 2 is a schematic view of a main part of the processing liquid supply device and a processing liquid supply nozzle. It is sectional drawing which shows the structure, and FIG. 3 is a sectional view which shows the cleaning state of the processing liquid supply nozzle. [0020] In this SOD coating processing unit (treatment liquid supply device) A, an annular cup CP is arranged at the center of the bottom of the unit, and a spin chuck is arranged inside the annular cup CP. The spin chuck is configured to rotate by the rotational driving force of the driving motor while the wafer W is fixedly held by vacuum suction. The treatment liquid supply nozzle B is detachably attached to the tip of the nozzle scan arm 81 by the nozzle standby portion 80 arranged on the outside of the cup CP, and is set as a predetermined coating liquid (treatment liquid) above the spin chuck. ) It is designed to be transferred to the discharge position. The nozzle scan arm 81 is attached to the upper end of a vertical support member 83 that can move horizontally on a guide rail 82 laid on the bottom plate of the unit in one direction (Y direction), and is mounted by a Y direction drive mechanism (not shown). It is designed to move in the Y direction integrally with the vertical support member 83. [0021] [0021] The nozzle scan arm 81 can also be moved in the X direction perpendicular to the Y direction in order to selectively attach the processing liquid supply nozzle B at the nozzle standby unit 80, and is also moved in the X direction by an X direction drive mechanism (not shown). It is designed to do. [0022] Further, the discharge port of the treatment liquid supply nozzle B is inserted into the mouth 80a of the solvent atmosphere chamber by the nozzle standby unit 80, and is exposed to the atmosphere of the solvent inside, so that the treatment liquid at the tip of the nozzle does not solidify or deteriorate. There is. Further, a plurality of treatment liquid supply nozzles B are provided, and these nozzles can be used properly according to the type of treatment liquid. [0023] Further, a drain cup 84 is provided between the cup CP and the nozzle standby portion 90, and at this position, the treatment liquid supply nozzle B is washed before or after the treatment liquid is supplied to the wafer W. It has become like. This cleaning will be described later. [0024] Further, on the guide rail 82, not only the vertical support member 83 that supports the nozzle scan arm 81 described above, but also the vertical support member 86 that supports the rinse nozzle scan arm 85 and can move in the Y direction is provided. A rinse nozzle 87 for side rinsing is attached to the tip of the rinse nozzle scan arm 85. The rinse nozzle scan arm 85 and the rinse nozzle 87 are placed on the nozzle standby position (solid line position) set on the side of the cup CP and the wafer W mounted on the spin chuck by the Y-direction drive mechanism (not shown). It is designed to translate or move linearly with the rinse liquid discharge position (dotted line position) set directly above the peripheral edge. Then, after the insulating film material is supplied onto the wafer W from the processing liquid supply nozzle B, the solvent is supplied to the peripheral portion of the wafer W surface by the rinse nozzle 87 to dissolve and remove the insulating film material in this portion. As a result, it is possible to prevent the insulating film of the wafer W from coming into contact with somewhere and peeling off to generate dust when the wafer W is being conveyed by the conveying system. [0025] In FIG. 1, the pipes connected to the treatment liquid supply nozzle B and the rinse nozzle 87 are omitted from the figure in order to facilitate the illustration. Also, in FIG. 1, the shutter attached to the opening 89 for the tweezers 88 to enter and exit the station is omitted from the figure. [0026] Further, the SOD coating processing unit (treatment liquid supply device) A will be described with reference to FIG. The main configuration of the treatment liquid supply device A is that the treatment liquid supply device A has a treatment liquid supply nozzle B and a coating liquid supply source 9 that supplies a coating liquid (treatment liquid) to the treatment liquid supply nozzle B. The cleaning liquid supply source 13 that supplies the cleaning liquid when cleaning the treatment liquid supply nozzle B, the gas supply source 12 that supplies the gas when supplying the cleaning liquid or when drying after cleaning, and the treatment liquid supply nozzle B. It is composed of a conveying means such as a nozzle scan arm 81 for moving the gas. [0027] First, the configuration of the processing liquid supply nozzle B will be described. The treatment liquid supply nozzle B has a nozzle 1 having a discharge port for a coating liquid (treatment liquid), a nozzle holder 2 having a through hole 2a through which the nozzle 1 is inserted, and capable of accommodating the nozzle 1, and the nozzle. The holder base 3 that holds the holder 2 so that it can move up and down, the coating liquid supply pipe 4 that supplies the coating liquid (treatment liquid) to the nozzle 1, the nozzle fixing portion 6 that fixes the nozzle 1, and the holder base 3. It is composed of a holding portion 5 that fixes the nozzle fixing portion 6 and is fixed to the nozzle scan arm 81. The nozzle holder 2 is designed so that it can be easily attached and detached, and the nozzle 1 can be easily replaced by removing the nozzle holder 2. [0028] The lower portion of the nozzle 1 is formed in the shape of a circular tube having a small diameter, and a discharge port 1a, which is a first discharge port for discharging the coating liquid, is provided at the tip thereof. Further, the upper portion of the nozzle 1 is formed in a large-diameter cylindrical shape, and a through hole 1b connected to the discharge port 1a is formed in the central portion thereof. Further, a screw portion 1c is formed on the outer peripheral surface of the upper portion of the nozzle 1, and the nozzle 1 is screwed and fixed to the screw portion 6c of the nozzle fixing portion 6. Further, the coating liquid supply pipe 4 is fitted and fixed in the through hole 1b of the nozzle 1, and the coating liquid supplied from the coating liquid supply pipe 4 is led out from the discharge port 1a of the nozzle 1. ing. [0029] The nozzle 1 is made of a Teflon (registered trademark) material, which is a synthetic resin having good heat resistance and chemical resistance. Since the Teflon (registered trademark) material has water repellency, the outer peripheral surface thereof is roughened and made hydrophilic so that the cleaning liquid can easily flow down evenly when cleaning the nozzle 1. This rough surface processing is performed by, for example, a chemical treatment such as UV irradiation or a mechanical treatment such as filing. [0030] The nozzle fixing portion 6 is formed with a through hole 6a through which the coating liquid supply pipe 4 is fitted and fixed. A screw portion 6b is formed on the upper outer peripheral surface of the nozzle fixing portion 6, and is screwed and fixed to the screw portion 5b of the holding portion 5 fixed to the nozzle scan arm 81. As described above, since the nozzle 1 is fixed to the holding portion 5 via the nozzle fixing portion 6, the nozzle 1 does not swing during the spin coating. [0031] Further, as described above, a through hole 2a through which the lower portion (tip portion 1d) of the nozzle 1 is inserted is formed in the central portion of the nozzle holder 2. Further, the nozzle holder 2 is formed in a bowl shape, and a space S into which the cleaning liquid is introduced is formed between the inner peripheral surface of the nozzle holder 2 and the outer peripheral surface of the nozzle 1. Further, a screw portion 2b is formed on the outer peripheral surface of the nozzle holder 2 and is screwed with the screw portion 3b of the holder base 3. Then, by rotating the nozzle holder 2, the nozzle holder 2 is formed so as to be vertically movable with respect to the holder base 3. The vertical movement of the nozzle holder 2 is performed by the rotational operation of the holder drive unit 11. [0032] The through hole 2a of the nozzle holder 2 functions as a discharge port which is a second discharge port for discharging the cleaning liquid. A gap at a predetermined interval is formed between the outer peripheral surface of the nozzle 1 and the inner peripheral surface of the through hole 2a so that the nozzle holder 2 can move up and down without contacting the nozzle 1. In the state of FIG. 2 in which the coating liquid (treatment liquid) is discharged, the tip portion 1d of the nozzle 1 projects downward from the through hole 2a. On the other hand, in the state of FIG. 3 in which the nozzle 1 is being washed, the nozzle holder 2 moves downward, and the entire nozzle 1 is housed inside the nozzle holder 2 and is covered by the nozzle holder 2. Has been done. [0033] Further, the nozzle holding portion 5 is provided with a cleaning liquid for cleaning the nozzle 1 or N for drying the cleaning liquid.₂A liquid / gas supply port 15 for supplying gas such as gas to the space S is provided. A cleaning liquid supply source 13 which is a cleaning liquid supply means and a gas supply source 12 which is a gas supply means are connected to the liquid / gas supply port 15 via a valve 14. Further, a coating liquid supply source 9 which is a coating liquid supply means is connected to the coating liquid supply pipe 4 via a valve 10. [0034] The nozzle holding portion 5 (screw portion 5a) and the holder base 3 (screw portion 3a) are screwed and fixed via the packing 7. Further, the nozzle holding portion 5 is configured so that the nozzle scan arm 81 is connected and the processing liquid supply nozzle B can be moved between a position on the wafer and a position on a drain cup (not shown) which is a nozzle standby position. ing. [0035] The operation from the discharge of the coating liquid (treatment liquid) to the nozzle cleaning in the treatment liquid supply device A configured as described above will be described. First, when the coating liquid (treatment liquid) for forming the insulating film is discharged from the nozzle 1 onto the wafer, first, as shown in FIG. 2, the discharge port 1a of the nozzle 1 is discharged from the through hole 2a of the nozzle holder 2. Make it in a protruding state. Then, the nozzle scan arm 81 connected to the nozzle holding portion 5 conveys the discharge port 1a of the nozzle 1 so as to be located at a predetermined distance from the wafer W directly above the center of the wafer W. [0036] After that, the wafer W is rotated, then the valve 10 is opened, and the coating liquid is supplied from the coating liquid (treatment liquid) supply source 9 to the coating liquid (treatment liquid) supply pipe 4 by means such as a pump. Then, the coating liquid (treatment liquid) supplied to the coating liquid supply pipe 4 is discharged onto the wafer W from the discharge port 1a of the nozzle 1. At this time, since the wafer W is rotating, the coating liquid (treatment liquid) supplied on the wafer W is stretched and coated on the entire surface of the wafer W by centrifugal force. [0037] When the coating operation on the wafer W is completed, the valve 10 is closed. At this time, the discharge port 1a of the nozzle 1 is in an open state, but since the valve 10 is closed, the coating liquid (treatment liquid) remaining between the valve 10 and the discharge port 1a of the nozzle 1 is on the surface. It does not fall from the discharge port 1a due to tension. Next, the treatment liquid supply nozzle B is conveyed onto a drain cup (not shown) by the nozzle scan arm 81 to which the nozzle holding portion 5 is fixed. Then, the valve 10 is opened again, and the coating liquid remaining between the valve 10 and the discharge port 1a of the nozzle 1 is discharged into the drain cup 84. [0038] Next, the coating liquid (treatment liquid) adhering to the tip 1d of the nozzle 1 is cleaned. The nozzle holder 2 is moved downward by the rotational operation of the holder drive unit 11, and the entire nozzle 1 is housed and covered in the nozzle holder 2 as shown in FIG. Then, the cleaning liquid supply source 13 side is opened in the valve 14, and the pump of the cleaning liquid supply source 13 is driven to supply the cleaning liquid from the liquid / gas supply port 15 to the space S. At this time, the cleaning liquid is supplied to the space S between the nozzle 1 and the nozzle holder 2 so as to be stored to some extent. The supplied cleaning liquid flows down into the drain cup 84 from the through hole 2a which is the discharge port of the nozzle holder 2. In this way, cleaning is performed while maintaining the state in which the cleaning liquid is stored in the space S between the nozzle 1 and the nozzle holder 2, and the entire outer peripheral surface of the nozzle 1 is evenly cleaned with the cleaning liquid. The coating liquid adhering to the nozzle 1 is discharged into the drain cup 84 from the through hole 2a of the nozzle holder 2 by the cleaning liquid. [0039] Subsequently, the cleaning liquid remaining on the outer peripheral surface of the nozzle 1 and the inner peripheral surface of the nozzle holder 2 is dried. At the valve 14, the cleaning liquid supply source 13 side is closed and the gas supply source 12 side is opened. As a result, gas sources 12 to N₂Gas is supplied to the liquid / gas supply port 15 and N₂After being supplied to the space S, the gas is discharged to the outside through the through hole 2a of the nozzle holder 2. At this time, high pressure N₂By supplying the gas, the cleaning liquid adhering to the outer peripheral surface of the nozzle 1 and the inner peripheral surface of the nozzle holder 2 can be dried in a short time. Then, after this drying process is performed, the valve 14 is closed and N from the gas supply source 12 is N.₂By stopping the gas supply, a series of operations from the discharge of the coating liquid (treatment liquid) to the nozzle cleaning is completed. [0040] As described above, in the embodiment according to the present invention, when cleaning the nozzle, the entire nozzle 1 is covered with the nozzle cover 2, and the cleaning liquid is stored in the space S between the outer peripheral surface of the nozzle 1 and the inner peripheral surface of the nozzle cover 2. By flowing down, the entire outer peripheral surface of the nozzle 1 can be washed evenly. That is, it is possible to prevent the harmful effect that the coating liquid (treatment liquid) remains without spreading the cleaning liquid, and it is possible to suppress problems such as coating unevenness and film thickness fluctuation. [0041] Further, in the above embodiment, the cleaning liquid is supplied for cleaning, and then the gas is supplied for drying. However, when the cleaning liquid is supplied, the gas may be supplied at the same time. In this way, if the cleaning liquid and gas are supplied at the same time, the gas is mixed in the cleaning liquid, and in addition to the cleaning effect of the cleaning liquid itself, the cleaning effect of gas bubbles can be obtained, and the entire outer peripheral surface of the nozzle 1 can be more reliably obtained. The coating liquid adhering to the water can be washed. [0042] Next, a second embodiment in which the nozzle holder 2 is modified will be described with reference to FIGS. 4 to 6. The members that are the same as or correspond to the members shown in FIGS. 1 to 3 in FIGS. 4 to 6 are designated by the same reference numerals, and detailed description thereof will be omitted. The form shown in FIG. 4 differs from the first embodiment shown in FIG. 2 only in the shape of the nozzle holder. That is, the nozzle holder 20 shown in FIG. 4 has a spiral groove 20b formed on its inner peripheral surface as shown in FIG. The spiral groove 20b is formed so as to start from the inner peripheral surface of the intermediate portion of the nozzle holder 20 and connect to the through hole 20a of the nozzle holder 20, and generate a rotating flow in the cleaning liquid supplied to the space S. As a result, the cleaning liquid evenly flows down the entire outer peripheral surface of the nozzle 1 and cleans the entire outer peripheral surface of the nozzle 1. [0043] Even in the treatment liquid supply device in which the nozzle holder 20 configured in this way is used, the coating liquid (treatment liquid) is discharged in a state where the nozzle 1 protrudes from the nozzle holder 20 as shown in FIG. It is done. When cleaning the nozzle 1, the nozzle holder 20 is moved downward by the holder drive unit 11 as shown in FIG. 6, and the entire nozzle 1 is accommodated and covered by the nozzle holder 2. Then, as in the first embodiment described above, the valve 14 is opened to supply the cleaning liquid from the cleaning liquid supply source 13 to the space S between the outer peripheral surface of the nozzle 1 and the inner peripheral surface of the nozzle holder 2. At this time, the cleaning liquid flows down while maintaining the state of being stored in the space S, but since it flows along the spiral groove formed on the inner peripheral surface of the nozzle holder 2, the flow of the cleaning liquid becomes a rotary flow, which is more effective. The coating liquid adhering to the nozzle 1 can be flushed off. [0044] Further, during the drying process, the cleaning liquid supply source 13 side is closed and the gas supply source 12 side is opened in the valve 14, and the gas supply source 12 to N₂Gas is supplied to the liquid / gas supply port 15. At this time, since the gas flows along the spiral groove formed on the inner peripheral surface of the nozzle holder 2, this gas flow also becomes a rotary flow, and the cleaning liquid is dried more effectively. [0045] Further, also in this embodiment, when the cleaning liquid is supplied, the gas may be supplied at the same time. In this way, when the cleaning liquid and the gas are supplied at the same time, the gas is mixed in the cleaning liquid, and the cleaning effect of the cleaning liquid itself, the effect of the rotating flow of the cleaning liquid, and the cleaning effect of the gas bubbles can be obtained, which is more reliable. The coating liquid (treatment liquid) adhering to the entire outer peripheral surface of the nozzle 1 can be washed. [0046] In the first and second embodiments described above, the nozzle holder 2 (nozzle holder 20) is rotated by the nozzle holder drive unit 11 to move it up and down, and the entire nozzle 1 is the nozzle holder 2 (nozzle holder). It is configured to be housed and covered in 20). However, the present invention is not limited to this, and the nozzle 1 itself may be moved up and down so that the entire nozzle 1 is accommodated and covered by the nozzle holder 2 (nozzle holder 20). Further, in the first and second embodiments described above, the nozzle holder 2 (nozzle holder 20) is configured to be rotated by the nozzle holder drive unit 11, but the nozzle 1 is located in the nozzle standby portion or the drain cup portion. A mechanism for rotating the nozzle may be provided. Further, the nozzle holder 2 (nozzle holder 20) may be manually rotated. [0047] Further, in the first and second embodiments described above, the SOD coating processing unit (treatment liquid supply device) in the SOD system has been described as an example, but the present invention not only forms an interlayer insulating film by the SOD system but also forms an interlayer insulating film. It can be applied to the formation of SOG (Spin On Glass) films and the formation of resist films, polymid films, ferroelectrics, other insulating films and the like. In the above embodiment, the apparatus for processing a semiconductor wafer has been described, but the present invention can also be applied to an apparatus for processing a glass substrate used for an FPD (flat panel display), a mask, or the like. [0048] [Effect of the invention] As is clear from the above description, the treatment liquid supply nozzle and the treatment liquid supply device can evenly clean the entire nozzle outer peripheral surface when cleaning the nozzle outer peripheral surface, and can surely wash away the treatment liquid remaining on the nozzle outer peripheral surface. In addition, a nozzle cleaning method can be obtained. [Simple explanation of drawings] FIG. 1 is a schematic plan view showing a first embodiment according to the present invention. FIG. 2 is a schematic cross-sectional view showing a main part of the first embodiment according to the present invention. FIG. 3 is a schematic cross-sectional view showing a cleaning state of the processing liquid supply nozzle shown in FIG. FIG. 4 is a schematic cross-sectional view showing a second embodiment in which the nozzle holder is deformed. FIG. 5 is a plan view of the nozzle holder shown in FIG. FIG. 6 is a schematic cross-sectional view showing a cleaning state of the processing liquid supply nozzle shown in FIG. FIG. 7 is a cross-sectional view showing a schematic configuration of a conventional processing liquid supply device. [Explanation of symbols] A Processing liquid supply device B Processing liquid supply nozzle S space W wafer 1 nozzle 1a (first) outlet 2 Nozzle holder 2a Through hole (second discharge port) 3 holder base 4 Coating liquid (treatment liquid) supply pipe 5 Nozzle holder 6 Nozzle fixing part 9 Coating liquid (treatment liquid) source 11 Holder drive unit 12 gas source 13 Cleaning liquid source 15 Liquid / gas supply port 20 Nozzle holder 20b spiral groove 80 Nozzle standby part 81 Nozzle scan arm 82 Guide rail 83 Vertical support member 84 drain cup