JP2015173148A - substrate processing apparatus and substrate processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processing apparatus and a substrate processing method, which can precisely detect discharge of a process liquid from a nozzle regardless of a type of a substrate to be a processing target.SOLUTION: A substrate processing method comprises the steps of: imaging an imaging area including a tip of a top face process liquid nozzle 30 which reciprocates between a processing position above a substrate W held by a spin chuck 20 and a standby position outside a processing cup 40, by a camera 70 before the top face process liquid nozzle 30 moving to the processing position discharges the process liquid to acquire a discharge reference image; and subsequently, comparing a plurality of monitoring target images sequentially, which are acquired by imaging the imaging area in series by the camera 70 with the discharge reference image to determine discharge of the process liquid from the top face process liquid nozzle 30. Since every time a substrate W to be a new processing target is processed, the discharge reference image is acquired, discharge of the process liquid can be precisely detected by removing the influence of a substrate surface which is caught in both of the monitoring target image and the discharge reference image as back grounds.

Description

  The present invention relates to a substrate processing apparatus and a substrate for performing predetermined processing by discharging a processing liquid from a nozzle onto a thin plate-like precision electronic substrate (hereinafter simply referred to as “substrate”) such as a semiconductor wafer or a glass substrate for a liquid crystal display device. It relates to the processing method.

  Conventionally, in a manufacturing process of a semiconductor device or the like, substrate processing such as cleaning processing or resist coating processing is performed by supplying various processing solutions such as pure water, a photoresist solution, and an etching solution to the substrate. As an apparatus for performing a liquid processing using these processing liquids, a substrate processing apparatus that discharges a processing liquid from a nozzle onto the surface of the substrate while rotating the substrate in a horizontal posture is widely used.

  In such a substrate processing apparatus, it is confirmed whether or not the processing liquid is being discharged from the nozzle by checking the output of the flow meter or the operation of the pump. As a technique, for example, Patent Document 1 proposes that an imaging unit such as a CCD camera is provided to directly monitor the discharge of the processing liquid from the nozzle.

JP 11-329936 A

  However, when the processing liquid ejection from the nozzle is directly monitored by the imaging unit, the background at the time of imaging varies depending on the type of substrate to be processed. That is, in general, various films such as a resist film and an insulating film are formed on the surface of the substrate to form a pattern. The reflectivity of the substrate surface varies greatly depending on the type of film and the pattern formed, and as a result, the background at the time of imaging varies depending on the type of substrate to be processed. For this reason, depending on the type of film deposited on the surface and the pattern formed, the noise of the image captured by the imaging means becomes large, and the discharge of the processing liquid from the nozzle cannot be accurately detected. Has occurred.

  The present invention has been made in view of the above problems, and provides a substrate processing apparatus and a substrate processing method capable of reliably detecting discharge of a processing liquid from a nozzle regardless of the type of a substrate to be processed. The purpose is to do.

  In order to solve the above-mentioned problem, the invention of claim 1 is a substrate processing apparatus, comprising a substrate holding part for holding a substrate, a cup surrounding the periphery of the substrate holding part, a nozzle for discharging a processing liquid, A drive unit that moves the nozzle between a processing position above the substrate held by the substrate holding unit and a standby position outside the cup, and an imaging region that includes the tip of the nozzle at the processing position The first reference image acquired by the imaging unit imaging the imaging region before the nozzle moved to the processing position discharges the processing liquid and the monitoring acquired by imaging the imaging region thereafter A determination unit that compares the target image and determines discharge of the processing liquid from the nozzle, and the imaging unit holds the substrate to be processed by the substrate holding unit, and the nozzle performs the processing. Move to position And obtaining a first reference image for each that.

  According to a second aspect of the present invention, in the substrate processing apparatus according to the first aspect of the invention, the imaging unit is held by the substrate holding unit from the tip of the nozzle among images acquired by imaging the imaging region. A storage unit configured to store a determination region set including a part up to the substrate, wherein the determination unit has a difference between the first reference image and the monitoring target image in the determination region equal to or greater than a predetermined threshold value; For example, it is determined that the processing liquid is discharged from the nozzle.

  The substrate processing apparatus according to a second aspect of the present invention is the substrate processing apparatus according to the second aspect of the present invention, wherein the imaging unit is configured to hold the substrate to be newly processed by the substrate holding unit, and the nozzle is moved from the standby position. The imaging area is continuously imaged at a predetermined interval from the start of movement toward the processing position, and the determination unit has a constant difference between consecutive images acquired by the imaging unit continuously imaging the imaging area. If it is less than the value, it is determined that the movement of the nozzle is stopped.

  According to a fourth aspect of the present invention, in the substrate processing apparatus according to the third aspect of the present invention, the determination unit determines that the movement of the nozzle is stopped in the images continuously acquired by the imaging unit. The image at is a first reference image.

  According to a fifth aspect of the present invention, in the substrate processing apparatus according to the fourth aspect of the present invention, the determination unit includes a plurality of monitoring target images acquired continuously by the imaging unit after determining the movement stop of the nozzle. The processing liquid discharge from the nozzle is determined by sequentially comparing with the first reference image.

  Further, the invention according to claim 6 is the substrate processing apparatus according to claim 5, wherein the determination unit normalizes the area of the determination region and compares the first reference image with the monitoring target image. Features.

  According to a seventh aspect of the present invention, in the substrate processing apparatus according to the sixth aspect of the invention, the determination unit has a moving average of differences between the first reference image and a predetermined number of monitoring target images equal to or greater than a predetermined threshold value. If there is, it is determined that the processing liquid is discharged from the nozzle.

  The invention according to claim 8 is the substrate processing apparatus according to any one of claims 4 to 7, wherein the determination unit is configured to capture the image when the nozzle is accurately positioned at the processing position. The unit compares the second reference image acquired by imaging the imaging region with the first reference image, and determines a position abnormality of the nozzle at the processing position.

  According to a ninth aspect of the present invention, in the substrate processing apparatus according to the eighth aspect of the present invention, the determination unit is configured such that the difference between the nozzle coordinates in the second reference image and the first reference image is equal to or greater than a predetermined threshold. It is determined that the position of the nozzle is abnormal.

  According to a tenth aspect of the present invention, in the substrate processing apparatus according to the eighth aspect of the present invention, the determination unit determines the first reference image and the monitoring target image based on a comparison result between the second reference image and the first reference image. The position of the determination region in is moved.

  Further, the invention of claim 11 is a substrate processing method, wherein a holding step of holding a substrate to be newly processed in the substrate holding portion, and a substrate to be newly processed is held in the substrate holding portion. A nozzle moving step of moving a nozzle for discharging a processing liquid from a standby position outside a cup surrounding the periphery of the substrate holding unit toward a processing position above the substrate held by the substrate holding unit; An imaging step in which an imaging region including the tip of the nozzle at the processing position is imaged by the imaging unit, and the imaging unit images and acquires the imaging region before the nozzle that has moved to the processing position discharges the processing liquid. A discharge determination step of comparing a first reference image and a monitoring target image acquired by imaging the imaging region thereafter to determine treatment liquid discharge from the nozzle. The nozzle while holding the substrate to the substrate holder becomes the new processing target and acquiring a first reference image for each moving in the processing position.

  The invention according to claim 12 is the substrate processing method according to claim 11, wherein the imaging unit is held by the substrate holding unit from the tip of the nozzle among images acquired by imaging the imaging region. The method further includes a step of presetting a determination region including a part leading up to the substrate, and in the ejection determination step, the nozzle is used if a difference in the determination region between the first reference image and the monitoring target image is equal to or greater than a predetermined threshold value. From the above, it is determined that the processing liquid is discharged.

  The invention of claim 13 is the substrate processing method according to the invention of claim 12, in the imaging step, the substrate holding unit holds a substrate to be newly processed, and the nozzle is moved from the standby position to the nozzle. If the imaging region is continuously captured at a predetermined interval from the start of movement toward the processing position, and the difference between successive images acquired by continuously capturing the imaging region by the imaging unit is equal to or less than a certain value The method further includes a stop determination step for determining that the movement of the nozzle has stopped.

  The invention according to claim 14 is the substrate processing method according to claim 13, wherein an image at a time when it is determined that the movement of the nozzle is stopped among images continuously acquired by the imaging unit. The first reference image is used.

  Further, the invention of claim 15 is the substrate processing method according to claim 14, wherein, in the discharge determination step, a plurality of images acquired continuously by the imaging unit after it is determined that the movement of the nozzle has stopped. The monitoring target image and the first reference image are sequentially compared to determine treatment liquid ejection from the nozzle.

  According to a sixteenth aspect of the present invention, in the substrate processing method according to the fifteenth aspect of the present invention, in the ejection determination step, the first reference image and the monitoring target image are compared by normalizing with an area of the determination region. It is characterized by.

  According to a seventeenth aspect of the present invention, in the substrate processing method according to the sixteenth aspect of the present invention, in the ejection determination step, a moving average of differences between the first reference image and a predetermined number of monitoring target images is a predetermined threshold value or more. Then, it is determined that the processing liquid is discharged from the nozzle.

  The invention according to claim 18 is the substrate processing method according to any one of claims 14 to 17, wherein the imaging section is in the imaging area when the nozzle is accurately positioned at the processing position. The method further includes a position determination step of comparing the second reference image acquired by imaging the first reference image and the first reference image to determine a position abnormality of the nozzle at the processing position.

  According to a nineteenth aspect of the present invention, in the substrate processing method according to the eighteenth aspect of the present invention, in the position determining step, a difference in coordinates of the nozzles in the second reference image and the first reference image is not less than a predetermined threshold value. For example, it is determined that the position of the nozzle is abnormal.

  According to a twentieth aspect of the present invention, in the substrate processing method according to the eighteenth aspect of the present invention, in the ejection determination step, the first reference image and the monitoring target are based on a comparison result between the second reference image and the first reference image. The position of the determination area in the image is moved.

  According to the first to tenth aspects of the present invention, the first reference image acquired by the imaging unit imaging the imaging region before the nozzle that has moved to the processing position ejects the processing liquid and the imaging region thereafter are imaged. Each time the nozzle is moved to the processing position with the substrate holding unit holding a new substrate to be processed. Therefore, the surface of the same substrate is included as the background in both the first reference image and the monitoring target image, and the influence of the reflectance of the substrate surface is eliminated. Regardless, it is possible to reliably detect the discharge of the processing liquid from the nozzle.

  In particular, according to the second aspect of the present invention, since the determination region including a part from the tip of the nozzle to the substrate held by the substrate holding part is set, the influence of the image reflected on the substrate surface, etc. And the first reference image can be compared with the monitoring target image.

  In particular, according to the invention of claim 3, since the movement of the nozzle is stopped if the difference between successive images acquired by the imaging unit continuously imaging the imaging region is equal to or less than a predetermined value, the movement of the nozzle is stopped. Can be automatically determined.

  In particular, according to the invention of claim 6, since the first reference image and the monitoring target image are compared by normalizing with the area of the determination region, the threshold value can be constant regardless of the size of the determination region. .

  In particular, according to the seventh aspect of the invention, if the moving average of the difference between the first reference image and the predetermined number of monitoring target images is equal to or greater than a predetermined threshold value, it is determined that the processing liquid is being discharged from the nozzle. In addition, the influence of noise during imaging can be reduced.

  In particular, according to the eighth aspect of the invention, the second reference image obtained by the imaging unit capturing an image of the imaging region when the nozzle is accurately positioned at the processing position is compared with the first reference image to compare the nozzle. In order to determine the position abnormality at the processing position, the nozzle position abnormality can be determined in addition to the discharge of the processing liquid.

  In particular, according to the invention of claim 10, since the position of the determination region in the first reference image and the monitoring target image is moved based on the comparison result between the second reference image and the first reference image, the stop position of the nozzle is set. Even if the proper processing position is slightly deviated, the determination area is set accurately.

  According to the eleventh to twentieth aspects of the present invention, the imaging unit captures the first reference image acquired by imaging the imaging region before the nozzle that has moved to the processing position discharges the processing liquid, and then the imaging region. Each time the nozzle is moved to the processing position with the substrate holding unit holding a new substrate to be processed. Therefore, the surface of the same substrate is included as the background in both the first reference image and the monitoring target image, and the influence of the reflectance of the substrate surface is eliminated. Regardless, it is possible to reliably detect the discharge of the processing liquid from the nozzle.

  In particular, according to the twelfth aspect of the present invention, since the determination region including a part from the tip of the nozzle to the substrate held by the substrate holding portion is set in advance, the influence of the image reflected on the substrate surface is set. The first reference image and the monitoring target image can be compared with each other.

  In particular, according to the invention of claim 13, since the movement of the nozzle is stopped if the difference between successive images acquired by the imaging unit continuously imaging the imaging region is equal to or smaller than a certain value, the movement of the nozzle is stopped. Can be automatically determined.

  In particular, according to the invention of claim 16, since the first reference image and the monitoring target image are compared by normalizing with the area of the determination region, the threshold value can be constant regardless of the size of the determination region. .

  In particular, according to the seventeenth aspect of the present invention, if the moving average of the difference between the first reference image and the predetermined number of monitoring target images is equal to or greater than a predetermined threshold value, it is determined that the processing liquid is discharged from the nozzle. In addition, the influence of noise during imaging can be reduced.

  In particular, according to the invention of claim 18, the nozzle unit compares the second reference image acquired by the imaging unit imaging the imaging region with the first reference image when the nozzle is accurately positioned at the processing position. In order to determine the position abnormality at the processing position, the nozzle position abnormality can be determined in addition to the discharge of the processing liquid.

  In particular, according to the twentieth aspect, since the position of the determination region in the first reference image and the monitoring target image is moved based on the comparison result between the second reference image and the first reference image, the stop position of the nozzle is set. Even if the proper processing position is slightly deviated, the determination area is set accurately.

It is a figure which shows the whole structure of the substrate processing apparatus which concerns on this invention. It is a top view of a washing processing unit. It is a longitudinal cross-sectional view of a washing | cleaning processing unit. It is a figure which shows the positional relationship of a camera and an upper surface process liquid nozzle. It is a block diagram of a camera and a control part. It is a flowchart which shows the procedure of the determination process by a determination part. It is a flowchart which shows the procedure of the determination process by a determination part. It is a figure which shows an example of the image obtained by imaging the imaging area containing the front-end | tip of the upper surface process liquid nozzle in a process position. It is a figure which shows the movement of the upper surface process liquid nozzle in an imaging region. It is a figure which shows a discharge reference | standard image and the monitoring object image. It is a figure which shows the comparison with the sum total of a difference, and a threshold value. It is a figure which shows typically an example of the algorithm of a process liquid discharge determination. It is a figure which shows typically the other example of the algorithm of a process liquid discharge determination.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration of a substrate processing apparatus 100 according to the present invention. The substrate processing apparatus 100 is a single wafer processing apparatus that processes substrates W for semiconductor use one by one, and performs a drying process after performing a cleaning process using a chemical solution and pure water on a circular silicon substrate W. Do. Typical chemicals include SC1 solution (ammonia water, hydrogen peroxide solution, water mixture), SC2 solution (hydrochloric acid, hydrogen peroxide solution, water mixture), DHF solution (diluted hydrofluoric acid), and the like. Used. In this specification, the chemical solution and the pure water are collectively referred to as “treatment solution”. It should be noted that not only the cleaning process but also a coating liquid such as a photoresist liquid for the film forming process, a chemical liquid for removing unnecessary films, a chemical liquid for etching, and the like are included in the “processing liquid” of the present invention.

  The substrate processing apparatus 100 includes an indexer 102, a plurality of cleaning processing units 1, and a main transfer robot 103. The indexer 102 has a function of loading an unprocessed substrate W received from outside the apparatus into the apparatus and unloading the processed substrate W after the cleaning process. The indexer 102 includes a plurality of carriers and a transfer robot (all not shown). As the carrier, a known FOUP (front opening unified pod) or SMIF (Standard Mechanical Interface Face) pod that stores the substrate W in a sealed space, or an OC (open cassette) that exposes the storage substrate W to the outside air can be used. . The transfer robot transfers the substrate W between the carrier and the main transfer robot 103.

  In the substrate processing apparatus 100, twelve cleaning processing units 1 are arranged. The detailed arrangement configuration is such that four towers in which three cleaning processing units 1 are stacked are arranged so as to surround the main transfer robot 103. In other words, four cleaning processing units 1 arranged around the main transfer robot 103 are stacked in three stages, and FIG. 1 shows one of them. The number of cleaning processing units 1 mounted on the substrate processing apparatus 100 is not limited to 12, and may be 8 or 4, for example.

  The main transfer robot 103 is installed at the center of four towers in which the cleaning processing units 1 are stacked. The main transfer robot 103 carries the unprocessed substrate W received from the indexer 102 into each cleaning processing unit 1 and unloads the processed substrate W from each cleaning processing unit 1 and passes it to the indexer 102.

  Next, the cleaning processing unit 1 will be described. Hereinafter, one of the twelve cleaning processing units 1 mounted on the substrate processing apparatus 100 will be described, but the same applies to the other cleaning processing units 1. FIG. 2 is a plan view of the cleaning processing unit 1. FIG. 3 is a longitudinal sectional view of the cleaning processing unit 1. FIG. 2 shows a state where the substrate W is not held on the spin chuck 20, and FIG. 3 shows a state where the substrate W is held on the spin chuck 20.

  In the chamber 10, the cleaning processing unit 1 performs processing on a spin chuck 20 that holds the substrate W as a main element in a horizontal posture (a normal line is a posture along the vertical direction), and an upper surface of the substrate W held on the spin chuck 20. Three upper surface processing liquid nozzles 30, 60, 65 for supplying liquid, a processing cup 40 surrounding the periphery of the spin chuck 20, and a camera 70 that images the space above the spin chuck 20 are provided. A partition plate 15 is provided around the processing cup 40 in the chamber 10 to partition the inner space of the chamber 10 up and down.

  The chamber 10 includes a side wall 11 along the vertical direction, a ceiling wall 12 that closes an upper side of a space surrounded by the side wall 11, and a floor wall 13 that closes a lower side. A space surrounded by the side wall 11, the ceiling wall 12, and the floor wall 13 is a processing space for the substrate W. A part of the side wall 11 of the chamber 10 is provided with a loading / unloading port for the main transfer robot 103 to load / unload the substrate W with respect to the chamber 10 and a shutter for opening / closing the loading / unloading port (both shown). (Omitted).

  A fan filter unit (FFU) 14 for further purifying the air in the clean room in which the substrate processing apparatus 100 is installed and supplying it to the processing space in the chamber 10 is attached to the ceiling wall 12 of the chamber 10. . The fan filter unit 14 includes a fan and a filter (for example, a HEPA filter) for taking in air in the clean room and sending it out into the chamber 10, and forms a downflow of clean air in the processing space in the chamber 10. In order to disperse the clean air supplied from the fan filter unit 14 uniformly, a punching plate having a large number of blowing holes may be provided directly below the ceiling wall 12.

  The spin chuck 20 includes a disk-shaped spin base 21 fixed in a horizontal posture at the upper end of a rotating shaft 24 extending along the vertical direction. A spin motor 22 that rotates the rotating shaft 24 is provided below the spin base 21. The spin motor 22 rotates the spin base 21 in the horizontal plane via the rotation shaft 24. Further, a cylindrical cover member 23 is provided so as to surround the periphery of the spin motor 22 and the rotating shaft 24.

  The outer diameter of the disk-shaped spin base 21 is slightly larger than the diameter of the circular substrate W held by the spin chuck 20. Therefore, the spin base 21 has a holding surface 21a that faces the entire lower surface of the substrate W to be held.

  A plurality (four in this embodiment) of chuck pins 26 are erected on the peripheral edge of the holding surface 21 a of the spin base 21. The plurality of chuck pins 26 are evenly spaced along the circumference corresponding to the outer circumference of the circular substrate W (if there are four chuck pins 26 as in this embodiment, the chuck pins 26 are spaced at 90 ° intervals. ) Is arranged. The plurality of chuck pins 26 are driven in conjunction with a link mechanism (not shown) housed in the spin base 21. The spin chuck 20 holds each of the plurality of chuck pins 26 in contact with the outer peripheral end of the substrate W to hold the substrate W, so that the substrate W is placed in a horizontal posture close to the holding surface 21 a above the spin base 21. Can be held (see FIG. 3), and each of the plurality of chuck pins 26 can be separated from the outer peripheral end of the substrate W to release the grip.

  The cover member 23 covering the spin motor 22 has a lower end fixed to the floor wall 13 of the chamber 10 and an upper end reaching just below the spin base 21. At the upper end portion of the cover member 23, a hook-like member 25 is provided that protrudes almost horizontally outward from the cover member 23 and further bends and extends downward. The spin motor 22 rotates the rotary shaft 24 in a state where the spin chuck 20 holds the substrate W by gripping by the plurality of chuck pins 26, thereby rotating around the rotation axis CX along the vertical direction passing through the center of the substrate W. The substrate W can be rotated. The driving of the spin motor 22 is controlled by the control unit 9.

  The upper surface treatment liquid nozzle 30 is configured by attaching a discharge head 31 to the tip of a nozzle arm 32. The proximal end side of the nozzle arm 32 is fixedly connected to the nozzle base 33. The nozzle base 33 can be rotated around an axis along the vertical direction by a motor (not shown). By rotating the nozzle base 33, the upper surface processing liquid nozzle 30 is located between the processing position above the spin chuck 20 and the standby position outside the processing cup 40, as indicated by an arrow AR34 in FIG. Move in an arc along the horizontal direction. The upper surface treatment liquid nozzle 30 is configured to be supplied with a plurality of kinds of treatment liquids (including at least pure water). The processing liquid discharged from the discharge head 31 of the upper surface processing liquid nozzle 30 at the processing position is deposited on the upper surface of the substrate W held by the spin chuck 20. Further, the upper surface treatment liquid nozzle 30 can be swung above the holding surface 21 a of the spin base 21 by the rotation of the nozzle base 33.

  Further, in the cleaning processing unit 1 of this embodiment, two upper surface processing liquid nozzles 60 and 65 are provided in addition to the upper surface processing liquid nozzle 30 described above. The upper surface treatment liquid nozzles 60 and 65 of the present embodiment have the same configuration as the upper surface treatment liquid nozzle 30 described above. That is, the upper surface treatment liquid nozzle 60 is configured by attaching a discharge head to the tip of a nozzle arm 62, and a spin base 20 as shown by an arrow AR64 by a nozzle base 63 connected to the base end side of the nozzle arm 62. Between the processing position above and the standby position outside the processing cup 40 moves in an arc. Similarly, the upper surface treatment liquid nozzle 65 is configured by attaching a discharge head to the tip of a nozzle arm 67, and a nozzle base 68 connected to the base end side of the nozzle arm 67 as shown by an arrow AR69. It moves in a circular arc shape between the processing position above 20 and the standby position outside the processing cup 40. A plurality of kinds of processing liquids including at least pure water are also supplied to the upper surface processing liquid nozzles 60 and 65, and the processing liquid is applied to the upper surface of the substrate W held by the spin chuck 20 at the processing position. Discharge. At least one of the upper surface treatment liquid nozzles 60 and 65 mixes a cleaning liquid such as pure water and a pressurized gas to generate droplets, and jets a mixed fluid of the droplets and gas onto the substrate W. A two-fluid nozzle may be used. Further, the number of nozzles provided in the cleaning processing unit 1 is not limited to three, and may be one or more.

  On the other hand, a lower surface treatment liquid nozzle 28 is provided along the vertical direction so as to pass through the inside of the rotation shaft 24. The upper end opening of the lower surface treatment liquid nozzle 28 is formed at a position facing the lower surface center of the substrate W held by the spin chuck 20. A plurality of types of processing liquids are also supplied to the lower surface processing liquid nozzle 28. The processing liquid discharged from the lower surface processing liquid nozzle 28 is deposited on the lower surface of the substrate W held by the spin chuck 20.

  The processing cup 40 surrounding the spin chuck 20 includes an inner cup 41, an intermediate cup 42, and an outer cup 43 that can be moved up and down independently of each other. The inner cup 41 surrounds the periphery of the spin chuck 20 and has a shape that is substantially rotationally symmetric with respect to the rotation axis CX that passes through the center of the substrate W held by the spin chuck 20. The inner cup 41 includes an annular bottom 44 in plan view, a cylindrical inner wall 45 rising upward from the inner periphery of the bottom 44, a cylindrical outer wall 46 rising upward from the outer periphery of the bottom 44, and an inner wall The first guide portion 47 that rises from between the portion 45 and the outer wall portion 46 and extends obliquely upward in the center side (in the direction approaching the rotation axis CX of the substrate W held by the spin chuck 20) while drawing a smooth arc at the upper end portion. And a cylindrical middle wall portion 48 that rises upward from between the first guide portion 47 and the outer wall portion 46.

  The inner wall portion 45 is formed in such a length as to be accommodated with an appropriate gap between the cover member 23 and the bowl-shaped member 25 in a state where the inner cup 41 is raised most. The middle wall portion 48 is accommodated with a suitable gap between a second guide portion 52 (described later) of the middle cup 42 and the processing liquid separation wall 53 in a state where the inner cup 41 and the middle cup 42 are closest to each other. It is formed in such a length.

  The first guide portion 47 has an upper end portion 47b extending obliquely upward in the center side (in the direction approaching the rotation axis CX of the substrate W) while drawing a smooth arc. Further, a space between the inner wall portion 45 and the first guide portion 47 is a disposal groove 49 for collecting and discarding the used processing liquid. A space between the first guide portion 47 and the middle wall portion 48 is an annular inner collection groove 50 for collecting and collecting used processing liquid. Further, a space between the middle wall portion 48 and the outer wall portion 46 is an annular outer collection groove 51 for collecting and collecting different types of processing liquids from the inner collection groove 50.

  The waste groove 49 is connected to an exhaust liquid mechanism (not shown) for discharging the processing liquid collected in the waste groove 49 and forcibly exhausting the inside of the waste groove 49. For example, four exhaust fluid mechanisms are provided at equal intervals along the circumferential direction of the discard groove 49. The inner recovery groove 50 and the outer recovery groove 51 have a recovery mechanism for recovering the processing liquid collected in the inner recovery groove 50 and the outer recovery groove 51, respectively, in a recovery tank provided outside the substrate processing apparatus 1. (Both not shown) are connected. The bottoms of the inner recovery groove 50 and the outer recovery groove 51 are inclined by a slight angle with respect to the horizontal direction, and the recovery mechanism is connected to the lowest position. Thereby, the processing liquid that has flowed into the inner recovery groove 50 and the outer recovery groove 51 is smoothly recovered.

  The middle cup 42 surrounds the periphery of the spin chuck 20 and has a shape that is substantially rotationally symmetric with respect to the rotation axis CX passing through the center of the substrate W held by the spin chuck 20. The inner cup 42 is integrally provided with a second guide portion 52 and a cylindrical processing liquid separation wall 53 connected to the second guide portion 52.

  The second guide portion 52 draws a smooth arc on the outside of the first guide portion 47 of the inner cup 41 from the lower end portion 52a that is coaxial with the lower end portion of the first guide portion 47 and the upper end of the lower end portion 52a. However, it has an upper end 52b that extends obliquely upward in the center side (in the direction approaching the rotation axis CX of the substrate W) and a folded portion 52c that is formed by folding the tip of the upper end 52b downward. The lower end 52 a is accommodated in the inner collection groove 50 with an appropriate gap between the first guide portion 47 and the middle wall portion 48 in a state where the inner cup 41 and the middle cup 42 are closest to each other. The upper end portion 52b is provided so as to overlap the upper end portion 47b of the first guide portion 47 of the inner cup 41 in the vertical direction, and the first guide portion 47 is in a state where the inner cup 41 and the middle cup 42 are closest to each other. And close to the upper end portion 47b with a very small distance. Further, the folded portion 52c formed by folding the tip of the upper end portion 52b downward is in a state where the inner cup 41 and the middle cup 42 are closest to each other, and the folded portion 52c is the tip of the upper end portion 47b of the first guide portion 47. It is the length which overlaps with the horizontal direction.

  Further, the upper end portion 52b of the second guide portion 52 is formed so as to increase in thickness toward the lower side, and the treatment liquid separation wall 53 is provided so as to extend downward from the lower peripheral edge of the upper end portion 52b. It has a cylindrical shape. The processing liquid separation wall 53 is accommodated in the outer collection groove 51 with an appropriate gap between the inner wall portion 48 and the outer cup 43 in a state where the inner cup 41 and the inner cup 42 are closest to each other.

  The outer cup 43 surrounds the periphery of the spin chuck 20 outside the second guide portion 52 of the middle cup 42 and is substantially rotationally symmetric with respect to the rotation axis CX passing through the center of the substrate W held by the spin chuck 20. It has a shape. The outer cup 43 has a function as a third guide part. The outer cup 43 has a lower end portion 43a that is coaxially cylindrical with the lower end portion 52a of the second guide portion 52, and a center side while drawing a smooth arc from the upper end of the lower end portion 43a (in the direction approaching the rotation axis CX of the substrate W). The upper end portion 43b extends obliquely upward, and the folded portion 43c is formed by folding the tip end portion of the upper end portion 43b downward.

  The lower end portion 43a has an outer clearance groove with an appropriate gap between the processing liquid separation wall 53 of the inner cup 42 and the outer wall portion 46 of the inner cup 41 in a state where the inner cup 41 and the outer cup 43 are closest to each other. 51. The upper end portion 43b is provided so as to overlap the second guide portion 52 of the middle cup 42 in the vertical direction, and the upper end portion 52b of the second guide portion 52 is in a state where the middle cup 42 and the outer cup 43 are closest to each other. Close to each other with a very small distance. Further, the folded portion 43 c formed by folding the tip end portion of the upper end portion 43 b downward is in a state where the inner cup 42 and the outer cup 43 are closest to each other, and the folded portion 43 c is the same as the folded portion 52 c of the second guide portion 52. It is formed so as to overlap in the horizontal direction.

  Further, the inner cup 41, the middle cup 42, and the outer cup 43 can be moved up and down independently of each other. That is, each of the inner cup 41, the middle cup 42, and the outer cup 43 is provided with a lifting mechanism (not shown), and is lifted and lowered separately. As such an elevating mechanism, various known mechanisms such as a ball screw mechanism and an air cylinder can be employed.

  The partition plate 15 is provided so as to partition the inner space of the chamber 10 up and down around the processing cup 40. The partition plate 15 may be a single plate-like member surrounding the processing cup 40, or may be a combination of a plurality of plate-like members. Further, the partition plate 15 may be formed with through holes or notches penetrating in the thickness direction, and in this embodiment, the nozzle bases 33, 63, 68 of the upper surface treatment liquid nozzles 30, 60, 65 are provided. A through hole for passing a support shaft for support is formed.

  The outer peripheral end of the partition plate 15 is connected to the side wall 11 of the chamber 10. Further, the edge portion surrounding the processing cup 40 of the partition plate 15 is formed to have a circular shape having a diameter larger than the outer diameter of the outer cup 43. Therefore, the partition plate 15 does not become an obstacle to the raising and lowering of the outer cup 43.

  An exhaust duct 18 is provided in a part of the side wall 11 of the chamber 10 and in the vicinity of the floor wall 13. The exhaust duct 18 is connected in communication with an exhaust mechanism (not shown). Of the clean air supplied from the fan filter unit 14 and flowing down in the chamber 10, the air that has passed between the processing cup 40 and the partition plate 15 is discharged from the exhaust duct 18 to the outside of the apparatus.

  The camera 70 is installed in the chamber 10 and above the partition plate 15. FIG. 4 is a diagram illustrating a positional relationship between the camera 70 and the upper surface treatment liquid nozzle 30. The camera 70 includes, for example, a CCD that is one of solid-state image sensors, and an optical system such as an electronic shutter and a lens. The upper surface processing liquid nozzle 30 has a processing position (dotted line position in FIG. 4) above the substrate W held by the spin chuck 20 and a standby position outside the processing cup 40 (solid line position in FIG. 4) by the nozzle base 33. ). The processing position is a position where the cleaning liquid is discharged from the upper surface processing liquid nozzle 30 onto the upper surface of the substrate W held by the spin chuck 20 to perform a cleaning process. The standby position is a position where the upper surface processing liquid nozzle 30 stops and waits for discharge of the processing liquid when the cleaning process is not performed. A standby pod that accommodates the ejection head 31 of the upper processing liquid nozzle 30 may be provided at the standby position.

  The camera 70 is installed at a position where the imaging field of view includes at least the tip of the upper processing liquid nozzle 30 at the processing position, that is, the vicinity of the ejection head 31. In the present embodiment, as shown in FIG. 4, a camera 70 is installed at a position where the upper processing liquid nozzle 30 at the processing position is photographed from the upper front. Therefore, the camera 70 can image the imaging region including the tip of the upper surface processing liquid nozzle 30 at the processing position. Similarly, the camera 70 can image an imaging region including the tips of the upper surface processing liquid nozzles 60 and 65 at the processing position. When the camera 70 is installed at the position shown in FIGS. 2 and 4, the upper surface processing liquid nozzles 30 and 60 move in the lateral direction within the photographing field of view of the camera 70, and therefore move near the processing position. However, since the upper surface processing liquid nozzle 65 moves in the depth direction within the imaging field of view of the camera 70, there is a possibility that the amount of movement in the vicinity of the processing position cannot be properly imaged. In such a case, a camera dedicated to the upper processing liquid nozzle 65 may be provided separately from the camera 70.

  As shown in FIG. 3, an illumination unit 71 is provided in the chamber 10 and above the partition plate 15. Normally, since the chamber 10 is a dark room, the illumination unit 71 irradiates light to the upper surface processing liquid nozzles 30, 60, 65 near the processing position when the camera 70 performs imaging.

  FIG. 5 is a block diagram of the camera 70 and the control unit 9. The configuration of the control unit 9 provided in the substrate processing apparatus 100 as hardware is the same as that of a general computer. That is, the control unit 9 stores a CPU that performs various arithmetic processes, a ROM that is a read-only memory that stores basic programs, a RAM that is a readable and writable memory that stores various information, control software, data, and the like. It is configured with a magnetic disk to be placed. When the CPU of the control unit 9 executes a predetermined processing program, each operation mechanism of the substrate processing apparatus 100 is controlled by the control unit 9, and processing in the substrate processing apparatus 100 proceeds.

  The determination unit 91 illustrated in FIG. 5 is a function processing unit that is realized in the control unit 9 when the CPU of the control unit 9 executes a predetermined processing program. Although details will be described later, the determination unit 91 performs various determination processes by performing image processing on an image captured by the camera 70. Further, the storage unit 92 in the control unit 9 is configured by the above-described RAM or magnetic disk, and stores data, input values, and the like of an image captured by the camera 70.

  Next, the operation in the substrate processing apparatus 100 having the above configuration will be described. The normal processing procedure of the substrate W in the substrate processing apparatus 100 is as follows. An unprocessed substrate W received by the main transfer robot 103 from the indexer 102 is carried into each cleaning processing unit 1, and the substrate W is cleaned by the cleaning processing unit 1. Then, the main transfer robot 103 carries out the processed substrate W from the cleaning processing unit 1 and returns it to the indexer 102. An outline of a typical cleaning process procedure for the substrate W in each cleaning processing unit 1 is that a chemical solution is supplied to the surface of the substrate W to perform a predetermined chemical processing, and then pure water is supplied to perform a pure water rinsing process. Thereafter, the substrate W is rotated at a high speed to perform a shake-off drying process.

  When processing the substrate W in the cleaning processing unit 1, the substrate W is held on the spin chuck 20 and the processing cup 40 moves up and down. When performing the chemical treatment, for example, only the outer cup 43 rises, and the substrate W held by the spin chuck 20 between the upper end portion 43b of the outer cup 43 and the upper end portion 52b of the second guide portion 52 of the middle cup 42 is used. An opening is formed to surround the periphery of the. In this state, the substrate W is rotated together with the spin chuck 20, and a chemical solution is supplied to the upper and lower surfaces of the substrate W from the upper surface processing liquid nozzle 30 and the lower surface processing liquid nozzle 28. The supplied chemical liquid flows along the upper and lower surfaces of the substrate W due to the centrifugal force generated by the rotation of the substrate W, and is eventually scattered from the edge of the substrate W to the side. Thereby, the chemical treatment of the substrate W proceeds. The chemical solution splashed from the edge of the rotating substrate W is received by the upper end portion 43 b of the outer cup 43, flows down along the inner surface of the outer cup 43, and is collected in the outer collection groove 51.

  When performing the pure water rinsing process, for example, all of the inner cup 41, the middle cup 42 and the outer cup 43 are raised, and the periphery of the substrate W held by the spin chuck 20 is the first guide portion 47 of the inner cup 41. Surrounded by. In this state, the substrate W is rotated together with the spin chuck 20, and pure water is supplied to the upper and lower surfaces of the substrate W from the upper surface processing liquid nozzle 30 and the lower surface processing liquid nozzle 28. The supplied pure water flows along the upper and lower surfaces of the substrate W due to the centrifugal force generated by the rotation of the substrate W, and is eventually scattered from the edge of the substrate W to the side. Thereby, the pure water rinse process of the board | substrate W advances. The pure water splashed from the edge of the rotating substrate W flows down the inner wall of the first guide portion 47 and is discharged from the discard groove 49. In the case where pure water is collected by a path different from the chemical solution, the middle cup 42 and the outer cup 43 are raised, and the upper end portion 52b of the second guide portion 52 of the middle cup 42 and the first guide of the inner cup 41 are collected. An opening surrounding the periphery of the substrate W held by the spin chuck 20 may be formed between the upper end portion 47 b of the portion 47.

  Further, when performing the swing-off drying process, all of the inner cup 41, the middle cup 42 and the outer cup 43 are lowered, and the upper end portion 47 b of the first guide portion 47 of the inner cup 41 and the second guide portion 52 of the middle cup 42 are moved. Both the upper end portion 52 b and the upper end portion 43 b of the outer cup 43 are positioned below the substrate W held by the spin chuck 20. In this state, the substrate W is rotated at a high speed together with the spin chuck 20, and water droplets adhering to the substrate W are shaken off by a centrifugal force, and a drying process is performed.

  In the present embodiment, when the processing liquid is discharged from the upper surface processing liquid nozzle 30 onto the upper surface of the substrate W, the determination unit 91 displays the image obtained by photographing the upper surface processing liquid nozzle 30 at the processing position by the camera 70. Performs predetermined image processing to determine whether or not the processing liquid is discharged. Hereinafter, the technique will be described in detail. Here, the processing liquid discharge determination from the upper surface processing liquid nozzle 30 will be described, but the same applies to the other upper surface processing liquid nozzles 60 and 65.

  6 and 7 are flowcharts showing the procedure of the determination process by the determination unit 91. FIG. 6 shows a procedure for preliminary preparation for determination processing, and FIG. 7 shows a determination processing procedure when the substrate W to be processed is carried into the cleaning processing unit 1. 6 is performed prior to the processing process of the substrate W to be actually processed, and may be performed at the time of maintenance work of the substrate processing apparatus 100, for example.

  First, when performing the teaching of the upper surface processing liquid nozzle 30 during maintenance work or the like, the upper surface processing liquid nozzle 30 is moved to the teaching position (step S11). Teaching is an operation for teaching the upper surface processing liquid nozzle 30 to operate properly, and corrects the stop position of the upper surface processing liquid nozzle 30 to an appropriate position (teaching position). Therefore, when the upper surface processing liquid nozzle 30 is moved to the teaching position during teaching, the upper surface processing liquid nozzle 30 is accurately moved to an appropriate processing position. The proper processing position is a position where the required substrate processing is performed if the processing liquid is discharged from the upper surface processing liquid nozzle 30 at the processing position.

  When the upper surface processing liquid nozzle 30 moves to an appropriate processing position, the imaging region including the tip of the upper surface processing liquid nozzle 30 is imaged by the camera 70 (step S12). FIG. 8 is a diagram illustrating an example of an image obtained by imaging the imaging region including the tip of the upper surface processing liquid nozzle 30 at the processing position by the camera 70. The imaging area PA includes the tip of the upper processing liquid nozzle 30 located at the processing position above the substrate W held by the spin chuck 20. Since the substrate W may not be held on the spin chuck 20 during maintenance, the substrate W may not necessarily be included in the imaging area PA.

  Next, a reference pattern is cut out from the image obtained by imaging in step S12 (step S13). At the time of imaging in step S12, the upper surface processing liquid nozzle 30 is accurately positioned at an appropriate processing position by teaching. Therefore, the image obtained by imaging with the camera 70 in step S12 can be a nozzle position reference image (second reference image) indicating an appropriate processing position of the upper surface processing liquid nozzle 30. In step S13, a partial image region including the tip portion of the upper processing liquid nozzle 30 is cut out from the nozzle position reference image as a reference pattern RP as shown in FIG. This cutting may be performed, for example, by manually specifying an area to be the reference pattern RP while viewing the image captured in step S12 during teaching. The extracted reference pattern RP is stored in the storage unit 92 of the control unit 9 together with the coordinates in the image (step S14).

  Subsequently, the worker sets a threshold for determining position abnormality (step S15). The threshold value set here is for use in determining the position abnormality of the upper surface processing liquid nozzle 30 (step S26 in FIG. 7), which will be described later, and in the reference pattern RP of the nozzle position reference image captured in step S12. This is a threshold value for deviation between the nozzle position and the nozzle position in the image specified in step S25. As the threshold value set here is lower, it is determined that the position of the upper surface treatment liquid nozzle 30 is abnormal even if the nozzle position deviation in both images is small. That is, the criterion for judgment becomes strict. The threshold set in step S15 is stored in the storage unit 92.

  Next, the ejection determination area is set in the image obtained by imaging in step S12 (step S16). As illustrated in FIG. 8, the image obtained by the camera 70 imaging the imaging area PA includes the substrate W held by the spin chuck 20 and the cleaning processing unit 1 in addition to the vicinity of the top end of the upper processing liquid nozzle 30. The internal devices are reflected. When determining the processing liquid discharge from the upper surface processing liquid nozzle 30, it is preferable to reduce the influence of the background as much as possible, and in particular, it is necessary to eliminate the influence of the processing liquid image reflected on the surface of the substrate W. . For this reason, in step S <b> 16, the ejection determination area including a part from the tip of the upper surface treatment liquid nozzle 30 to the substrate W held by the spin chuck 20 in the image acquired by the camera 70 imaging the imaging area PA. SP is set. This setting may also be made by manually specifying an area while an operator looks at the image captured in step S12. The set ejection determination area SP is stored in the storage unit 92 of the control unit 9. Note that the ejection determination area SP set here is not the image itself, unlike the reference pattern RP described above, but is an area in the image acquired by the camera 70 imaging the imaging area PA, for example, as shown in FIG. It is represented by coordinate data indicating a quadrangle of the ejection determination area SP.

  Following the setting of the discharge determination area SP, the worker sets a threshold value for discharge determination (step S17). The threshold value set here is for use in determination of processing liquid discharge described later (step S28 in FIG. 7), and is a threshold value of the difference between images before and after discharging the processing liquid imaged by the camera 70. The lower the threshold set here, the easier it is to determine that the processing liquid has been ejected from the upper surface processing liquid nozzle 30 even if the difference is small. The threshold set in step S17 is stored in the storage unit 92.

  As described above, preliminary preparation for the upper surface processing liquid nozzle 30 is performed. The same advance preparation as shown in steps S11 to S17 is performed for the other upper surface processing liquid nozzles 60 and 65 (step S18). Such advance preparation is sufficient if it is performed in advance when teaching is performed, and once it is performed, it is not necessary to perform it again until the teaching position is changed. Note that the preliminary preparation process as described above is not performed for the fixed lower surface treatment liquid nozzle 28.

  Next, a procedure when processing the substrate W to be processed after the advance preparation shown in FIG. 6 is performed will be described with reference to FIG. First, the substrate W to be processed is carried into the cleaning processing unit 1 by the main transfer robot 103 (step S21). The loaded substrate W is held in a horizontal posture by the spin chuck 20. At the same time, the raising and lowering operation is performed so that the processing cup 40 reaches a predetermined height position.

  After the substrate W to be newly processed is held on the spin chuck 20, the upper surface processing liquid nozzle 30 starts to move from the standby position toward the processing position (step S22). The upper processing liquid nozzle 30 is moved by the control unit 9 controlling the nozzle base 33 in accordance with a preset recipe (which describes the processing procedure and conditions of the substrate W). In addition, when the processing liquid discharge from the upper surface processing liquid nozzle 30 for a predetermined time or longer (for example, 5 seconds or longer) is described in the recipe, the control unit 9 starts to move the upper surface processing liquid nozzle 30. The determination unit 91 is instructed to perform the discharge determination at the same timing. The timing at which the control unit 9 issues a discharge determination instruction may not be exactly the same as when the upper surface processing liquid nozzle 30 starts to move, but the determination unit 91 does not stop until the upper surface processing liquid nozzle 30 stops moving. However, it is preferable to carry out with sufficient margin so that the process after step S23 can be performed.

  The determination unit 91 that has received the discharge determination instruction causes the camera 70 to start continuous imaging (step S23). The camera 70 continuously images the imaging area PA at a constant interval. For example, the camera 70 performs continuous imaging at intervals of 33 milliseconds (30 frames per second). That is, the camera 70 starts moving image shooting from the time when the spin chuck 20 holds a new substrate W to be processed and the upper surface processing liquid nozzle 30 starts moving from the standby position toward the processing position. Note that when the camera 70 starts continuous imaging, it is also the time when the upper surface processing liquid nozzle 30 starts to move from the standby position, and thus the upper surface processing liquid nozzle 30 does not reach the imaging area PA.

  After the camera 70 starts continuous imaging, the determination unit 91 determines stop of the movement of the upper surface processing liquid nozzle 30 (step S24). The movement of the upper surface treatment liquid nozzle 30 itself is performed by the control unit 9 controlling the nozzle base 33 according to the above recipe, and the stop of the movement is also controlled by the control unit 9. The determination unit 91 determines whether or not the upper surface treatment liquid nozzle 30 has stopped moving from a plurality of images acquired by the camera 70 by continuous imaging independently from the control by the control unit 9. Specifically, the determination unit 91 calculates the difference between successive images acquired by the camera 70 by continuously capturing the imaging area PA, and determines whether or not the upper surface treatment liquid nozzle depends on whether the difference is equal to or less than a certain value. The stop of the movement of 30 is determined. The calculation of the difference between successive images is to obtain the sum total of the absolute values of the gradation values of all the pixels in the difference image between one image and the next image among a plurality of images acquired by continuous imaging. It is.

  FIG. 9 is a diagram illustrating movement of the upper surface treatment liquid nozzle 30 in the imaging area PA. When the upper surface processing liquid nozzle 30 is moving in the imaging area PA and the camera 70 continuously images the imaging area PA, the position of the upper surface processing liquid nozzle 30 is different between a certain image and the next image. In the difference between these two images, an image of the treatment liquid nozzle 30 remains. On the other hand, when the camera 70 continuously images the imaging area PA after the upper surface processing liquid nozzle 30 stops moving at the processing position (dotted line position in FIG. 9) in the imaging area PA, an image and the next image are displayed. The position of the upper surface treatment liquid nozzle 30 is the same, and the upper surface treatment liquid nozzle 30 also disappears in the difference between the two images. Therefore, if the sum of gradation values of all pixels in an image of a difference between successive images (difference between a certain image and the next image) acquired by the camera 70 continuously capturing the imaging area PA is less than a certain value. The determination unit 91 determines that the upper surface treatment liquid nozzle 30 has stopped moving. In order to prevent erroneous determination due to noise or the like, for example, the determination unit 91 calculates a difference between a certain image and the next image for five consecutive images (in this case, four differences are calculated), If all the differences are less than or equal to a certain value, it may be determined that the upper surface treatment liquid nozzle 30 has stopped moving.

  Next, the determination unit 91 discharges an image at the time when it is determined in step S24 that the movement of the upper surface processing liquid nozzle 30 has been stopped, from among images continuously acquired by the camera 70. It is specified as a reference image (first reference image) (step S25). The identified ejection reference image is stored in the storage unit 92 of the control unit 9. The ejection reference image obtained in this way is an image obtained by imaging the imaging area PA when the upper surface processing liquid nozzle 30 reaches the processing position and stops. When the upper surface processing liquid nozzle 30 reaches the processing position and stops, the processing liquid is not yet discharged from the upper surface processing liquid nozzle 30. Therefore, the ejection reference image is an image acquired by the camera 70 imaging the imaging area PA before the upper surface processing liquid nozzle 30 moved to the processing position discharges the processing liquid.

  Further, the processes from step S21 to step S25 are processes that are executed each time the substrate W to be newly processed is carried into the cleaning processing unit 1. That is, in the present embodiment, a discharge reference image is acquired each time the spin chuck 20 holds the substrate W to be newly processed that has been carried into the cleaning processing unit 1 and the upper surface processing liquid nozzle 30 moves to the processing position. It is doing.

  Next, the determination unit 91 compares the nozzle position reference image and the discharge reference image to determine a position abnormality in the processing position of the upper surface processing liquid nozzle 30 (step S26). The nozzle position reference image is an image acquired by the camera 70 imaging the imaging area PA when the upper surface processing liquid nozzle 30 is accurately positioned at the processing position during teaching. The ejection reference image is an image acquired by the camera 70 imaging the imaging area PA when the spin chuck 20 holds the substrate W to be processed and the upper surface processing liquid nozzle 30 moves to the processing position and stops. . Therefore, by comparing the nozzle position reference image with the discharge reference image, it can be determined whether or not the upper surface processing liquid nozzle 30 that has moved above the substrate W to be processed has stopped at an appropriate processing position. .

  Specifically, the determination unit 91 compares the reference pattern RP of the nozzle position reference image cut out in step S13 with the partial region image in the discharge reference image corresponding to the reference pattern RP, and compares the images in both images. A difference (positional deviation) in coordinates of the upper surface treatment liquid nozzle 30 is calculated. A known pattern matching technique can be used for this comparison. If the positional deviation of the upper surface processing liquid nozzle 30 calculated by pattern matching is equal to or greater than the threshold value set in step S15, the determination unit 91 determines that the position of the upper surface processing liquid nozzle 30 is abnormal. . When it is determined that the position of the upper surface processing liquid nozzle 30 is abnormal, the control unit 9 performs predetermined abnormality handling processing (for example, warning generation or processing stoppage). On the other hand, when the calculated positional deviation of the upper surface processing liquid nozzle 30 is smaller than the threshold value set in step S <b> 15, the determination unit 91 determines that there is no abnormality in the position of the upper surface processing liquid nozzle 30.

  After the upper surface processing liquid nozzle 30 reaches the processing position and stops, the substrate W is rotated by the control of the control unit 9 and the processing liquid discharge from the upper surface processing liquid nozzle 30 is started. Then, the determination unit 91 determines discharge of the processing liquid from the upper surface processing liquid nozzle 30 based on images continuously captured by the camera 70.

  The determination unit 91 shifts the discharge determination region SP when determining whether to discharge the processing liquid (step S27). The ejection determination area SP is set in step S16 as an area including a part from the tip of the upper surface treatment liquid nozzle 30 to the substrate W in the nozzle position reference image. In step S26 described above, a positional deviation between the position of the upper surface processing liquid nozzle 30 in the nozzle position reference image and the position of the upper surface processing liquid nozzle 30 in the discharge reference image is calculated. In step S27, the determination unit 91 shifts the discharge determination region SP based on the calculation result. That is, the ejection determination area SP is moved by the amount of displacement calculated in step S26.

  Even after it is determined in step S24 that the movement of the upper surface treatment liquid nozzle 30 is stopped, the camera 70 performs continuous imaging of the imaging area PA. That is, the camera 70 starts continuous imaging of the imaging area PA at the same time when the upper surface treatment liquid nozzle 30 starts moving (step S23), and then continues continuous imaging at a constant interval.

  The determination unit 91 includes a discharge reference image acquired by the camera 70 imaging the imaging area PA before the upper surface processing liquid nozzle 30 moved to the processing position discharges the processing liquid, and then the camera 70 images the imaging area PA. Then, the processing liquid ejection from the upper surface processing liquid nozzle 30 is determined by comparing with the acquired monitoring target image (step S28). More specifically, the determination unit 91 sequentially compares the plurality of monitoring target images acquired by the camera 70 after determining the stoppage of the movement of the upper surface processing liquid nozzle 30 and the discharge reference image, and sequentially detects the upper surface processing liquid nozzle. The processing liquid discharge from 30 is determined.

  The monitoring target image is an image acquired by imaging the imaging area PA by the camera 70 after the time when it is determined that the movement of the upper surface processing liquid nozzle 30 has stopped (that is, after the ejection reference image is specified). is there. Even after it is determined that the movement of the upper surface treatment liquid nozzle 30 is stopped, the camera 70 continuously captures the imaging area PA, and thus a plurality of monitoring target images captured at regular intervals are acquired. Then, since the discharge of the processing liquid is started after a lapse of a predetermined time after the upper surface processing liquid nozzle 30 stops moving at the processing position, it is obtained after any one of the plurality of monitoring target images. The discharge of the processing liquid is reflected in the image. The determination unit 91 sequentially compares the plurality of monitoring target images and the discharge reference image to determine the processing liquid discharge from the upper surface processing liquid nozzle 30.

  FIG. 10 is a diagram illustrating a discharge reference image and a monitoring target image. FIG. 10A shows the discharge determination area SP of the discharge reference image, and FIG. 10B shows the discharge determination area SP of the monitoring target image after the discharge of the treatment liquid is started. FIG. 12 is a diagram schematically illustrating an example of an algorithm for determining treatment liquid discharge. The determination unit 91 determines the difference between the gradation value of each pixel in the ejection determination area SP in one of the plurality of monitoring target images and the gradation value of the pixel in the ejection determination area SP in the ejection reference image corresponding to the pixel. Is integrated for all pixels included in the ejection determination area SP. That is, the determination unit 91 calculates the sum of absolute values of differences between the gradation values of the pixels constituting FIG. 10A and the gradation values of the pixels constituting FIG. 10B corresponding to the pixels. calculate. Note that the ejection determination area SP of the ejection reference image and the monitoring target image are both areas shifted in step S27. Therefore, even if the stop position of the upper surface processing liquid nozzle 30 at the processing position is deviated from the teaching position to such an extent that it is not determined that the position is abnormal, the discharge determination region SP is one from the tip of the upper surface processing liquid nozzle 30 to the substrate W. It is accurately set as a region including a part.

  Subsequently, the determination unit 91 compares the sum of the differences calculated as described above with the threshold set in step S17. If the sum of the differences is equal to or greater than the threshold value set in advance in step S <b> 17, the determination unit 91 determines that the processing liquid is being discharged from the upper surface processing liquid nozzle 30. On the other hand, when the sum of the differences is smaller than the threshold value, the determination unit 91 determines that the processing liquid is not discharged from the upper surface processing liquid nozzle 30. The determination unit 91 sequentially performs such comparison for a plurality of monitoring target images acquired by the camera 70 imaging the imaging area PA after the time when it is determined that the movement of the upper surface processing liquid nozzle 30 is stopped.

  FIG. 11 is a diagram illustrating a comparison between the sum of differences and a threshold value. The vertical axis in the figure shows the total sum of the absolute values of the differences in pixel gradation values. The horizontal axis of the figure sequentially shows the numbers of a plurality of monitoring target images acquired after the time point when it is determined that the movement of the upper surface treatment liquid nozzle 30 has stopped. The monitoring target image (up to the tenth monitoring target image in FIG. 11) before the processing liquid is discharged from the upper surface processing liquid nozzle 30 is substantially the same as the discharge reference image shown in FIG. Therefore, the sum of absolute values of differences between the gradation values of the pixels in the ejection determination region SP in the monitoring target image and the gradation values of the pixels in the ejection determination region SP in the ejection reference image corresponding to the pixel is relatively low. , Smaller than the threshold value set in advance in step S17.

  On the other hand, as shown in FIG. 10B, the monitoring target image (the eleventh and subsequent monitoring target images in FIG. 11) after the processing liquid discharge from the upper processing liquid nozzle 30 is started is discharged. An image of the treated liquid is included. Therefore, the sum of the absolute values of the differences between the gradation values of the pixels in the ejection determination region SP in the monitoring target image and the gradation values of the pixels in the ejection determination region SP in the ejection reference image corresponding to the pixel is relatively high. , Larger than the threshold value set in advance in step S17.

  When the state in which it is determined that the processing liquid is being discharged from the upper surface processing liquid nozzle 30 continues for 2 seconds or longer, that is, when the imaging interval is 33 milliseconds, the determination unit 91 processes 60 or more monitoring target images. When it is determined that the liquid is being discharged, it is determined that the processing liquid is stably and reliably discharged from the upper surface processing liquid nozzle 30. On the other hand, even if a predetermined time (for example, 5 seconds) elapses from the time when it is determined that the movement of the upper surface processing liquid nozzle 30 has stopped, the sum of the differences in pixel gradation values does not exceed the threshold value, and the upper surface processing liquid nozzle When it is determined from 30 that the processing liquid is not discharged, it is determined that the processing liquid is abnormally discharged. The determination result of the treatment liquid discharge by the determination unit 91 may be displayed on, for example, a display attached to the control unit 9. Further, when it is determined that the processing liquid discharge from the upper surface processing liquid nozzle 30 is abnormal, the control unit 9 may perform an abnormality handling process such as a process stop.

  The above is the determination process for the upper surface processing liquid nozzle 30. However, when other upper surface processing liquid nozzles 60 and 65 are used, the upper surface processing liquid nozzle 60 is processed in the same procedure as shown in FIG. Alternatively, determination processing for the upper surface processing liquid nozzle 65 can be performed.

  In the present embodiment, the ejection reference image acquired by the camera 70 imaging the imaging area PA before the upper surface processing liquid nozzle 30 moved to the processing position ejects the processing liquid, and then the camera 70 captures the imaging area PA. The processing target liquid ejection from the upper surface processing liquid nozzle 30 is determined by comparing with the monitoring target image acquired by imaging. Then, each time the upper processing liquid nozzle 30 moves to the processing position while the spin chuck 20 holds the substrate W to be newly processed that has been carried into the cleaning processing unit 1, an ejection reference image is acquired.

  The image obtained by the camera 70 imaging the imaging area PA includes the substrate W held by the spin chuck 20 and the equipment in the cleaning processing unit 1 in addition to the vicinity of the tip of the upper processing liquid nozzle 30. ing. In order to eliminate as much as possible the influence of these backgrounds, particularly the influence of the image of the processing liquid reflected on the surface of the substrate W, the discharge determination area SP is set in advance, and the discharge determination area of the discharge reference image and the monitoring target image is set. Comparison with the threshold is performed by the difference in SP.

  However, as shown in FIG. 8, the image of the surface of the substrate W held by the spin chuck 20 cannot be removed from the ejection determination region SP. As described above, various films such as a resist film and an insulating film are formed on the surface of the substrate W to form a pattern. As a result, the surface reflectance varies greatly depending on the type of the substrate W.

  According to the present embodiment, the spin chuck 20 holds the substrate W to be newly processed and acquires the discharge reference image every time the upper surface processing liquid nozzle 30 moves to the processing position. The surface image of the same substrate W is included as the background in both the image and the monitoring target image. Therefore, the difference between the ejection reference image and the monitoring target image is eliminated regardless of the surface reflectance of the substrate W. As a result, regardless of the type of the substrate W to be processed, the discharge of the processing liquid from the upper surface processing liquid nozzle 30 can be reliably determined.

  Further, if the difference between successive images acquired by the camera 70 by continuously capturing the imaging area PA is equal to or less than a certain value, it is determined that the movement of the upper surface processing liquid nozzle 30 has stopped. The movement stop is automatically determined. For this reason, after the upper surface processing liquid nozzle 30 stops moving at the processing position, it is possible to determine whether the processing liquid is discharged from the upper surface processing liquid nozzle 30 by performing imaging with the camera 70 without sending a special trigger signal. it can. As a result, the hardware configuration relating to the processing liquid discharge determination can also be simplified.

  In addition to the determination of the processing liquid discharge, the determination unit 91 also determines a position abnormality when the upper surface processing liquid nozzle 30 moves to the processing position. If the upper surface processing liquid nozzle 30 is displaced from the teaching position and discharges the processing liquid due to an adjustment error during maintenance or a change over time, the expected result cannot be obtained, resulting in processing failure. In the present embodiment, since the position abnormality of the upper surface treatment liquid nozzle 30 is also determined, it is possible to prevent the occurrence of processing failure due to the positional deviation of the upper surface treatment liquid nozzle 30.

  While the embodiments of the present invention have been described above, the present invention can be modified in various ways other than those described above without departing from the spirit of the present invention. For example, in the above-described embodiment, when the determination unit 91 determines the stop of the movement of the upper surface processing liquid nozzle 30, whether the difference between consecutive images acquired by continuous imaging by the camera 70 is a certain value or less. However, the determination is not limited to this, and the determination may be made by comparing each image with the nozzle position reference image. That is, the determination unit 91 performs pattern matching between a plurality of images acquired by the camera 70 by continuously capturing the imaging area PA and the nozzle position reference image acquired during teaching, and the coordinate variation of the upper surface treatment liquid nozzle 30 is constant. When the value is less than or equal to the value, it is determined that the upper surface treatment liquid nozzle 30 has stopped moving. Even in this case, the determination unit 91 performs pattern matching with the nozzle position reference image for, for example, five consecutive images, and the coordinate variation of the upper surface treatment liquid nozzle 30 is stably below a certain value. It is preferable to determine that the upper surface treatment liquid nozzle 30 has stopped moving.

  Further, an algorithm for determining discharge of the processing liquid from the upper surface processing liquid nozzle 30 may be as shown in FIG. The determination unit 91 determines the difference between the gradation value of each pixel in the discharge determination region SP in one of the plurality of monitoring target images and the gradation value of the pixel in the discharge determination region SP in the discharge reference image corresponding to the pixel. The point that the absolute value is integrated for all the pixels included in the ejection determination region SP is the same as in the above embodiment (FIG. 12). In the example illustrated in FIG. 13, the determination unit 91 compares the discharge reference image and the monitoring target image by normalizing the sum of the differences of the pixel gradation values by the area of the discharge determination region SP. That is, the determination unit 91 calculates the total difference per unit area by dividing the total sum of pixel gradation value differences by the area of the ejection determination region SP. Then, the determination unit 91 compares the sum of the differences of the pixel gradation values normalized by the area of the discharge determination region SP and the threshold set in advance in step S17, and discharges the processing liquid from the upper surface processing liquid nozzle 30. Determine. In the above embodiment, if the size of the ejection determination area SP set in step S16 changes, the sum of the differences in pixel gradation values also changes accordingly. As a result, the threshold value set in step S17 must also be changed. I must. In the example shown in FIG. 13, since the sum of the differences in pixel gradation values is normalized by the area of the ejection determination region SP, even if the size of the ejection determination region SP set in step S16 varies. The threshold set in step S17 can be operated without being changed.

  Further, in the example of FIG. 13, the determination unit 91 calculates a moving average of differences between the ejection reference image and a predetermined number of monitoring target images, and compares the moving average with a threshold value. That is, for example, the determination unit 91 individually calculates the sum of the differences in pixel gradation values from the discharge reference image for the five latest monitoring target images that are consecutive, and calculates the average value of the sum of the differences. Then, the determination unit 91 determines the discharge of the processing liquid from the upper surface processing liquid nozzle 30 by comparing the average value of the sum of the differences of the pixel gradation values with the threshold value set in advance in step S17. If the moving average of the difference is equal to or greater than the threshold set in step S17, it is determined that the processing liquid is being discharged from the upper surface processing liquid nozzle 30. By using such a moving average, it is possible to alleviate the influence of noise and variations included in a plurality of monitoring target images acquired by continuous imaging by the camera 70, and to perform more reliable ejection determination processing.

  The substrate to be processed by the substrate processing apparatus 100 is not limited to a substrate for semiconductor use, and may be a glass substrate used for a flat panel display such as a substrate for solar cell use or a liquid crystal display device.

  Furthermore, the technique according to the present invention can be applied to any apparatus that performs a predetermined process by discharging a processing liquid from a movable nozzle onto a substrate. For example, in addition to the single wafer cleaning apparatus of the above embodiment, a spin coater that applies a resist solution by discharging a photoresist solution from a nozzle to a rotating substrate, and a substrate on which a film is formed. The technique according to the present invention may be applied to a device that discharges the film removal liquid from the nozzle to the edge of the substrate, or a device that discharges the etching liquid from the nozzle to the surface of the substrate.

DESCRIPTION OF SYMBOLS 1 Cleaning process unit 9 Control part 10 Chamber 20 Spin chuck 30, 60, 65 Upper surface process liquid nozzle 33, 63, 68 Nozzle base 40 Processing cup 70 Camera 71 Illumination part 91 Determination part 92 Storage part 100 Substrate processing apparatus PA Imaging area RP Reference pattern SP Discharge judgment area W Substrate

Claims (20)

A substrate holder for holding the substrate;
A cup surrounding the periphery of the substrate holder;
A nozzle for discharging the treatment liquid;
A drive unit that moves the nozzle between a processing position above the substrate held by the substrate holding unit and a standby position outside the cup;
An imaging unit for imaging an imaging region including a tip of the nozzle at the processing position;
A first reference image acquired by the imaging unit imaging the imaging area before the nozzle that has moved to the processing position discharges the processing liquid, and a monitoring target image acquired by imaging the imaging area thereafter. A determination unit for determining treatment liquid discharge from the nozzle in comparison;
With
The substrate processing apparatus, wherein the imaging unit acquires a first reference image each time the nozzle is moved to the processing position while the substrate holding unit holds a substrate to be newly processed. The substrate processing apparatus according to claim 1,
A storage unit for storing a determination region set including a part from the tip of the nozzle to the substrate held by the substrate holding unit in an image acquired by imaging the imaging region by the imaging unit; In addition,
The substrate processing apparatus, wherein the determination unit determines that the processing liquid is being discharged from the nozzle if a difference in the determination region between the first reference image and the monitoring target image is equal to or greater than a predetermined threshold. The substrate processing apparatus according to claim 2,
The imaging unit holds the imaging region continuously at a predetermined interval from the time when the substrate holding unit holds a substrate to be newly processed and the nozzle starts moving from the standby position toward the processing position. Image
The substrate processing apparatus according to claim 1, wherein the determination unit determines that the movement of the nozzle is stopped if a difference between successive images acquired by the imaging unit continuously imaging the imaging region is equal to or less than a predetermined value. The substrate processing apparatus according to claim 3, wherein
The substrate processing apparatus, wherein the determination unit sets, as a first reference image, an image at a time when it is determined that the movement of the nozzle is stopped among images continuously acquired by the imaging unit. The substrate processing apparatus according to claim 4, wherein
The determination unit sequentially determines a discharge of the processing liquid from the nozzle by sequentially comparing a plurality of monitoring target images acquired by the imaging unit and the first reference image after determining the movement stop of the nozzle. A substrate processing apparatus. The substrate processing apparatus according to claim 5,
The determination unit normalizes the area of the determination region and compares the first reference image with the monitoring target image. The substrate processing apparatus according to claim 6, wherein
The determination unit determines that the processing liquid is discharged from the nozzle if the moving average of the difference between the first reference image and the predetermined number of monitoring target images is equal to or greater than a predetermined threshold value. Processing equipment. In the substrate processing apparatus in any one of Claims 4-7,
The determination unit compares the first reference image with a second reference image acquired by the imaging unit capturing an image of the imaging region when the nozzle is accurately positioned at the processing position. A substrate processing apparatus for determining a position abnormality in the processing position. The substrate processing apparatus according to claim 8, wherein
The substrate processing apparatus, wherein the determination unit determines that the position of the nozzle is abnormal if a difference between the coordinates of the nozzles in the second reference image and the first reference image is equal to or greater than a predetermined threshold. The substrate processing apparatus according to claim 8, wherein
The determination unit moves a position of the determination region in the first reference image and the monitoring target image based on a comparison result between the second reference image and the first reference image. A holding step of holding a substrate to be newly processed in the substrate holding unit;
After a substrate to be newly processed is held by the substrate holding unit, the standby position outside the cup surrounding the periphery of the substrate holding unit is directed to a processing position above the substrate held by the substrate holding unit. A nozzle moving step for moving the nozzle for discharging the processing liquid;
An imaging step of imaging an imaging region including a tip of the nozzle at the processing position by an imaging unit;
A first reference image acquired by the imaging unit imaging the imaging area before the nozzle that has moved to the processing position discharges the processing liquid, and a monitoring target image acquired by imaging the imaging area thereafter. A discharge determination step for determining treatment liquid discharge from the nozzle in comparison;
With
In the imaging step, the substrate holding method holds a substrate to be newly processed, and acquires a first reference image every time the nozzle moves to the processing position. The substrate processing method according to claim 11,
A step of presetting a determination region including a part from the tip of the nozzle to the substrate held by the substrate holding unit in the image acquired by the imaging unit imaging the imaging region;
The substrate processing method according to claim 1, wherein in the discharge determination step, if the difference in the determination region between the first reference image and the monitoring target image is equal to or greater than a predetermined threshold, it is determined that the processing liquid is discharged from the nozzle. The substrate processing method according to claim 12, wherein
In the imaging step, the substrate holding unit holds a substrate to be newly processed and the imaging region is continuously detected at a predetermined interval from the time when the nozzle starts moving from the standby position toward the processing position. Image
A substrate processing method, further comprising: a stop determination step of determining that the movement of the nozzle is stopped if a difference between consecutive images acquired by the image pickup unit continuously imaging the image pickup region is a predetermined value or less. . The substrate processing method according to claim 13,
A substrate processing method, wherein an image at a time when it is determined that the movement of the nozzle is stopped among images continuously acquired by the imaging unit is used as a first reference image. 15. The substrate processing method according to claim 14, wherein
In the ejection determination step, the processing liquid from the nozzle is sequentially compared by comparing a plurality of monitoring target images continuously acquired by the imaging unit and the first reference image after it is determined that the movement of the nozzle is stopped. A substrate processing method characterized by determining ejection. The substrate processing method according to claim 15, wherein
In the ejection determination step, the substrate processing method is characterized in that the first reference image and the monitoring target image are compared by normalizing with the area of the determination region. The substrate processing method according to claim 16, wherein
In the discharge determination step, if the moving average of the difference between the first reference image and the predetermined number of monitoring target images is equal to or greater than a predetermined threshold value, it is determined that the processing liquid is discharged from the nozzle. Substrate processing method. The substrate processing method according to any one of claims 14 to 17,
When the nozzle is accurately positioned at the processing position, the imaging unit compares the second reference image acquired by imaging the imaging region with the first reference image, and the position of the nozzle at the processing position. A substrate processing method, further comprising a position determination step of determining abnormality. The substrate processing method according to claim 18, wherein
The substrate processing method according to claim 1, wherein, in the position determination step, the position of the nozzle is determined to be abnormal if a difference between the nozzle coordinates in the second reference image and the first reference image is equal to or greater than a predetermined threshold. The substrate processing method according to claim 18, wherein
In the ejection determination step, the position of the determination region in the first reference image and the monitoring target image is moved based on a comparison result between the second reference image and the first reference image.

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