CN114269481A

CN114269481A - Substrate processing apparatus, nozzle inspection method, and storage medium

Info

Publication number: CN114269481A
Application number: CN202080055978.1A
Authority: CN
Inventors: 滨田佳志; 只友浩贵; 桾本裕一朗; 羽山隆史
Original assignee: Tokyo Electron Ltd
Current assignee: Tokyo Electron Ltd
Priority date: 2019-08-13
Filing date: 2020-08-04
Publication date: 2022-04-01
Also published as: TW202120198A; KR20220044319A; WO2021029274A1; JPWO2021029274A1; JP2023133329A; JP7313449B2

Abstract

The substrate processing apparatus of the present invention comprises: a liquid nozzle for discharging the processing liquid to the substrate below from the discharge port; an imaging unit that images the entire circumference of the vicinity of the discharge opening of the liquid nozzle; and a control unit that executes: an image acquisition control that acquires an inspection image of the entire circumference in the vicinity of the discharge port of the liquid nozzle, the inspection image being captured by the imaging unit; and an evaluation control for evaluating the adhesion state of the adhering substance on the discharge opening of the liquid nozzle based on the inspection image of the entire circumference in the vicinity of the discharge opening of the liquid nozzle.

Description

Substrate processing apparatus, nozzle inspection method, and storage medium

Technical Field

The invention relates to a substrate processing apparatus, a nozzle inspection method, and a storage medium.

Background

Patent document 1 discloses the following technique: in a substrate processing apparatus, a discharge port portion of a liquid nozzle for supplying a processing liquid is imaged, and an abnormality is determined based on a state of a foreign substance.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2015-153913

Disclosure of Invention

Technical problem to be solved by the invention

The invention provides a technique capable of more appropriately evaluating the adhesion state of an adherent in the vicinity of a discharge port of a nozzle.

Technical solution for solving technical problem

A substrate processing apparatus according to an embodiment of the present invention includes: a liquid nozzle for discharging the processing liquid to the substrate below from the discharge port; an imaging unit that images the entire circumference of the liquid nozzle in the vicinity of the discharge port; and a control unit that executes: an image acquisition control unit that acquires an inspection image of the entire circumference around the discharge port of the liquid nozzle, the inspection image being captured by the imaging unit; and an evaluation control for evaluating the adhesion state of the adhering substance to the discharge opening of the liquid nozzle based on the inspection image of the entire circumference in the vicinity of the discharge opening of the liquid nozzle.

Effects of the invention

According to the present invention, the adhesion state of the adhering substance in the vicinity of the discharge port of the nozzle can be evaluated more appropriately.

Drawings

Fig. 1 is a perspective view showing a coating and developing system according to an exemplary embodiment.

FIG. 2 is a sectional view taken along line II-II of FIG. 1.

FIG. 3 is a sectional view taken along line III-III of FIG. 2.

Fig. 4 is a cross-sectional view showing an example of a substrate processing apparatus.

Fig. 5 is a diagram showing an example of a hardware configuration of the substrate processing apparatus.

Fig. 6 is a diagram showing a configuration example of the imaging unit.

Fig. 7 is a diagram showing a configuration example of the imaging unit.

Fig. 8 is a diagram showing a configuration example of the imaging unit.

Fig. 9 is a flowchart showing an example of a substrate inspection method performed by the substrate processing apparatus.

Fig. 10 is a flowchart showing an example of a substrate inspection method performed by the substrate processing apparatus.

Fig. 11 is a diagram showing an example of an image used in the substrate inspection method.

Fig. 12 is a diagram showing an example of an image used in the substrate inspection method.

Fig. 13 is a flowchart showing an example of a substrate inspection method performed by the substrate processing apparatus.

Fig. 14 is a diagram showing an example of an image used in the substrate inspection method.

Fig. 15 is a diagram showing an example of an image used in the substrate inspection method.

Fig. 16 is a diagram showing an example of an image used in the substrate inspection method.

Fig. 17 is a flowchart showing an example of a flow related to selection of a substrate cleaning method.

Detailed Description

Various exemplary embodiments will be described below.

In one exemplary embodiment, a substrate processing apparatus includes: a liquid nozzle for discharging the processing liquid to the substrate below from the discharge port; an imaging unit that images the entire circumference of the liquid nozzle in the vicinity of the discharge port; and a control unit that executes: an image acquisition control unit that acquires an inspection image of the entire circumference around the discharge port of the liquid nozzle, the inspection image being captured by the imaging unit; and an evaluation control for evaluating the adhesion state of the adhering substance to the discharge opening of the liquid nozzle based on the inspection image of the entire circumference in the vicinity of the discharge opening of the liquid nozzle.

According to the substrate processing apparatus described above, the adhesion state of the adhering substance to the discharge port of the liquid nozzle is evaluated based on the inspection image obtained by imaging the entire circumference in the vicinity of the discharge port of the liquid nozzle. In this way, the evaluation of the adhesion state of the adhering substance is performed based on the image obtained by imaging the entire circumference in the vicinity of the discharge port of the liquid nozzle, and therefore, the possibility of the liquid nozzle operating in a state where the adhering substance is adhered can be reduced. Therefore, the adhesion state of the adhering substance in the vicinity of the discharge port of the nozzle can be evaluated more appropriately.

The control unit may further execute determination control for determining an operation to be executed on the liquid nozzle based on an evaluation result in the evaluation control.

As described above, by adopting a configuration in which the control unit determines the operation to be performed on the liquid nozzle based on the evaluation result, it is possible to perform appropriate treatment in accordance with the evaluation result, and appropriate treatment can be performed in consideration of abnormality of the liquid nozzle and the like.

In the evaluation control, the control unit may estimate an area where an attached matter is attached to the liquid nozzle from the inspection image, evaluate an attachment state of the attached matter to the discharge port of the liquid nozzle based on a pixel value of the estimated area, and determine whether or not there is an abnormality in the liquid nozzle based on the evaluation result.

As described above, the attachment state of the attached matter to the discharge port of the liquid nozzle may be evaluated based on the pixel value of the region where the attached matter is captured in the inspection image, and whether or not there is an abnormality in the liquid nozzle may be determined based on the result of the evaluation. With such a configuration, it is possible to evaluate whether or not there is an abnormality substantially based on the amount of adhesion of the adhering matter, and it is possible to evaluate the adhesion state of the adhering matter more appropriately.

The control unit may be configured to estimate whether the adhering substance adhering to the liquid nozzle is a liquid or a solid based on an outline or a size of a region in which the adhering substance adhering to the liquid nozzle is captured, which is estimated from the inspection image, in the evaluation control.

As described above, by estimating whether the adhering substance adhering to the liquid nozzle estimated from the inspection image is a liquid or a solid, it is possible to estimate how strongly the adhering substance adheres to the vicinity of the discharge port of the liquid nozzle, and the like, and it is possible to estimate the adhesion state more appropriately.

The control unit may be configured to estimate an attachment position of an attached substance to the liquid nozzle based on the inspection image in the evaluation control.

As described above, by estimating the adhesion position of the adhering substance, it is possible to evaluate with higher accuracy how much the adhering substance affects the treatment using the nozzle.

In the determination control, the control unit may be configured to select a cleaning method of the liquid nozzle based on the evaluation result when it is determined that there is an abnormality in the liquid nozzle.

As described above, by adopting the configuration in which the cleaning method of the liquid nozzle is selected based on the evaluation result in the evaluation control, appropriate cleaning can be performed in accordance with the adhesion state of the adhering substance, and therefore the adhering portion can be appropriately removed from the nozzle.

In one exemplary embodiment, a nozzle inspection method for a substrate processing apparatus having a liquid nozzle for discharging a processing liquid from a discharge port to a substrate located below the substrate acquires an inspection image obtained by imaging the entire circumference of the liquid nozzle in the vicinity of the discharge port, and evaluates the adhesion state of an adhering substance to the discharge port of the liquid nozzle based on the inspection image of the entire circumference of the liquid nozzle in the vicinity of the discharge port.

According to the nozzle inspection method described above, the evaluation of the adhesion state of the adhering substance to the discharge port of the liquid nozzle is performed based on the image obtained by imaging the entire circumference in the vicinity of the discharge port of the liquid nozzle, and the possibility that the liquid nozzle operates in a state where the adhering substance adheres can be reduced. Therefore, the adhesion state of the adhering substance in the vicinity of the discharge port of the nozzle can be evaluated more appropriately.

In one exemplary embodiment, a computer-readable storage medium stores a program for causing an apparatus to execute the nozzle inspection method described above.

Various exemplary embodiments will be described in detail below with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals. Hereinafter, in order to clarify the positional relationship, an X axis, a Y axis, and a Z axis orthogonal to each other are defined as necessary, and the positive Z axis direction is set to the vertical upward direction.

[ operation of coating and developing apparatus ]

First, an outline of the structure of the coating and developing apparatus 1 shown in fig. 1 to 3 will be described. The coating and developing apparatus 1 performs a process of coating a resist material on the front side Wa of the wafer (substrate) W to form a resist film, prior to the exposure process by the exposure apparatus E1. The coating and developing apparatus 1 performs a developing process of a resist film formed on the front side Wa of the wafer W after the exposure process by the exposure apparatus E1. In the present embodiment, the wafer W has a disc shape, but a shape in which a part of a circle is cut off may be used, and a wafer having a shape other than a circle such as a polygon may be used.

As shown in fig. 1 and 2, the coating and developing apparatus 1 includes: carrier block S1; processing block S2; interface block S3; a control unit CU functioning as a control unit of the coating and developing apparatus 1; and a display unit D capable of displaying the processing result of the control unit CU. In this embodiment, the carrier block S1, the processing block S2, the interface block S3, and the exposure device E1 are sequentially arranged in series.

As shown in fig. 1 and 3, the carrier block S1 has the carrier station 12 and the carry-in/out section 13. The carrier station 12 supports a plurality of carriers 11. The carrier 11 accommodates a plurality of wafers W in a sealed state. The carrier 11 has an opening/closing door (not shown) for allowing the wafer W to enter and exit on the side of the one side surface 11 a. The carrier 11 is detachably provided on the carrier station 12 such that the side surface 11a faces the loading/unloading section 13.

As shown in fig. 1 to 3, the feeding and discharging unit 13 includes opening and closing doors 13a corresponding to the plurality of carriers 11 in the carrier station 12. When the opening/closing door of the side surface 11a and the opening/closing door 13a of the feeding/discharging unit 13 are opened at the same time, the inside of the carriage 11 communicates with the inside of the feeding/discharging unit 13. As shown in fig. 2 and 3, the feeding and discharging unit 13 incorporates a cross arm a 1. The transfer arm A1 takes the wafer W from the carrier 11 and transfers it to the processing block S2. Transfer arm A1 receives wafers W from processing block S2 and returns them to carrier 11.

As shown in fig. 1-3, processing tile S2 is adjacent to carrier tile S1 and is connected to carrier tile S1. As shown in fig. 1 and 2, the process block S2 has a lower layer antireflection film formation (BCT) block 14, a resist film formation (COT) block 15, an upper layer antireflection film formation (TCT) block 16, and a development process (DEV) block 17. The DEV block 17, the BCT block 14, the COT block 15, and the TCT block 16 are arranged in this order from the bottom surface side.

As shown in fig. 2, the BCT block 14 includes a coating unit (not shown), a heating/cooling unit (not shown), and a transfer arm a2 for transferring the wafer W to these units. The coating unit coats the front surface Wa of the wafer W with a chemical solution for forming the antireflection film. The heating and cooling unit heats the wafer W with a hot plate, for example, and then cools the wafer W with a cooling plate, for example. In this way, the lower antireflection film is formed on the front surface Wa of the wafer W.

As shown in fig. 2, the COT block 15 incorporates a coating unit (not shown), a heating and cooling unit (not shown), and a transfer arm a3 for transferring the wafer W to these units. The coating unit coats a chemical solution (resist material) for forming a resist film on the lower anti-reflection film. The heating and cooling unit heats the wafer W with a hot plate, for example, and then cools the wafer W with a cooling plate, for example. Thus, a resist film is formed on the lower anti-reflection film of the wafer W. The resist material may be either positive or negative.

As shown in fig. 2, the TCT block 16 includes a coating unit (not shown), a heating/cooling unit (not shown), and a transfer arm a4 for transferring the wafer W to these units. The coating unit coats a chemical solution for forming the antireflection film on the resist film. The heating and cooling unit heats the wafer W with a hot plate, for example, and then cools the wafer W with a cooling plate, for example. In this way, the upper antireflection film is formed on the resist film of the wafer W.

As shown in fig. 2 and 3, the DEV block 17 has a plurality of developing process units (substrate processing apparatuses) U1 and a plurality of heating and cooling units (heat treatment sections) U2. Further, the DEV block 17 incorporates a transfer arm a5 that transfers the wafers W to the units and a transfer arm a6 that transfers the wafers W between the front and rear of the process block S2 without passing through the units.

The developing process unit U1 performs a developing process of the exposed resist film as described later. The heating and cooling unit U2 heats the resist film on the wafer W by heating the wafer W with a hot plate, for example. The heating and cooling unit U2 cools the heated wafer W by, for example, a cooling plate. The heating and cooling unit U2 performs heating processes such as Post Exposure Bake (PEB) and Post Bake (PB). PEB is a process of heating the resist film before the development process. PB is a process of heating the resist film after the development process.

As shown in fig. 1 to 3, a shelf unit U10 is provided at the side of the carrier block S1 in the processing block S2. The shelf unit U10 has a plurality of cells C30-C38. The cells C30 to C38 are arranged in a vertical direction (Z-axis direction) between the DEV block 17 and the TCT block 16. A lift arm a7 is provided near the shelving unit U10. The lift arm A7 transfers the wafer W between the cells C30 to C38.

A shelf unit U11 is provided at the interface block S3 side among the processing blocks S2. The shelf unit U11 has a plurality of cells C40-C42. The cells C40 to C42 are arranged adjacent to the DEV block 17 and arranged in the vertical direction (Z-axis direction).

As shown in fig. 1 to 3, the interface block S3 is located between the processing block S2 and the exposure device E1, and is connected to the processing block S2 and the exposure device E1, respectively. As shown in fig. 2 and 3, interface block S3 has interface arm a8 built into it. The transfer arm A8 transfers the wafers W from the shelf unit U11 of the process block S2 to the exposure apparatus E1. The transfer arm A8 receives the wafer W from the exposure apparatus E1 and returns the wafer W to the shelf unit U11.

[ operation of control device ]

The control unit CU is formed by one or more control computers. For example, the control device 100 has a circuit 120 shown in fig. 5. The circuit 120 has one or more processors 121, a memory 122, a storage 123, and an input-output port 124. The memory 123 includes a computer-readable storage medium such as a hard disk. The storage medium stores a program for causing the control unit CU to execute a process flow described later. The storage medium may be a removable medium such as a nonvolatile semiconductor memory, a magnetic disk, and an optical disk. The memory 122 temporarily stores the program loaded from the storage medium of the memory 123 and the operation result of the processor 121. The processor 121 cooperates with the memory 122 to execute the programs, thereby constituting the functional blocks. The input/output port 124 inputs and outputs an electric signal to and from a component to be controlled in accordance with an instruction from the processor 121.

The hardware configuration of the control unit CU is not necessarily limited to the configuration of each functional block by a program. For example, each functional block of the control device 100 may be formed of a dedicated logic Circuit or an ASIC (Application Specific Integrated Circuit) that integrates these circuits.

As shown in fig. 1, the control unit CU includes a storage unit CU1 and a control unit CU 2. The storage unit CU1 stores programs for operating the respective units of the coating and developing apparatus 1 and the respective units of the exposure apparatus E1. The storage unit CU1 also stores various data (for example, size data of a foreign object and position data of a foreign object) and the imaging unit 26, which will be described in detail later. The storage unit CU1 is, for example, a semiconductor memory, an optical recording disk, a magnetic recording disk, or an optical magnetic recording disk. The program may be contained in an external memory separate from the storage unit CU1 or an intangible medium such as a propagation signal. The program may be installed from these other media to the storage unit CU1, and the storage unit CU1 may store the program. The control unit CU2 controls the operations of each unit of the coating and developing apparatus 1 and each unit of the exposure apparatus E1 based on the program read from the storage unit CU 1.

The control unit CU may be connected to the display unit D, and may display a screen for setting the processing conditions, the process of the wafer W by the coating and developing apparatus 1, the processing results, and the like on the display unit D. The coating and developing apparatus 1 may further include an input unit (not shown) through which an operator can input process conditions. In this case, the control unit CU may operate each unit of the coating and developing apparatus 1 and each unit of the exposure apparatus E1 according to the conditions input to the control unit CU through the input unit. Examples of the input unit include a mouse, a touch panel, a tablet, and a keyboard.

[ operation of coating and developing apparatus ]

Next, an outline of the operation of the coating and developing apparatus 1 will be described. First, the carrier 11 is set to the carrier station 12. At this time, one side surface 11a of the carriage 11 faces the opening/closing door 13a of the feeding/discharging unit 13. Subsequently, the open/close door of the carrier 11 and the open/close door 13a of the carry-in/out section 13 are opened together, and the wafers W in the carrier 11 are taken out by the transfer arm a1 and sequentially transferred to any of the shelf units U10 of the process block S2.

After the wafers W are transferred to any one of the shelf units U10 by the transfer arm a1, the wafers W are sequentially transferred to the cell C33 corresponding to the BCT block 14 by the lift arm a 7. The wafer W transferred to the cell C33 is transferred to each cell in the BCT block 14 by the transfer arm a 2. In the process of transferring the wafer W into the BCT block 14 by the transfer arm a2, the lower antireflection film is formed on the front side Wa of the wafer W.

The wafer W having the lower antireflection film formed thereon is transferred to the cell C34 above the cell C33 by the transfer arm a 2. The wafer W transferred to the cell C34 is transferred to the cell C35 corresponding to the COT block 15 by the lift arm a 7. The wafer W transferred to the cell C35 is transferred to each cell in the COT block 15 by the transfer arm A3. In the process of conveying the wafer W into the COT block 15 by the conveying arm a3, a resist film is formed on the lower antireflection film.

The wafer W on which the resist film is formed is transferred to the cell C36 above the cell C35 by the transfer arm a 3. The wafer W transferred to the cell C36 is transferred to the cell C37 corresponding to the TCT block 16 by the lift arm a 7. The wafer W transferred to the cell C37 is transferred to each cell in the TCT block 16 by the transfer arm A4. In the process of transporting the wafer W into the TCT block 16 by the transport arm a4, an upper antireflection film is formed on the resist film.

The wafer W having the upper antireflection film formed thereon was transferred to the cell C38 above the cell C37 by the transfer arm a 4. The wafer W transferred to the cell C38 is transferred to the cell C32 by the lift arm a7, and then transferred to the cell C42 of the rack unit U11 by the transfer arm a 6. The wafer W transferred to the cell C42 is transferred to the exposure apparatus E1 by the transfer arm a8 of the interface block S3, and the exposure process of the resist film is performed in the exposure apparatus E1. The wafer W subjected to the exposure process is transferred by the transfer arm A8 to the cells C40 and C41 below the cell C42.

The wafers W transferred to the cells C40 and C41 are transferred to the respective cells in the DEV block 17 by the transfer arm a5, and are subjected to the developing process. Thereby, a resist pattern (concave-convex pattern) is formed on the front side Wa of the wafer W. The wafer W formed with the resist pattern is transferred by the transfer arm a5 to the cells C30, C31 corresponding to the DEV block 17 in the shelf unit U10. The wafer W transferred to the cells C30 and C31 is transferred by the lift arm a7 to a cell accessible by the transfer arm a1, and is returned to the carrier 11 by the transfer arm a 1.

The configuration and operation of the coating and developing apparatus 1 described above are merely examples. The coating and developing apparatus 1 may include a liquid processing unit such as a coating unit and a developing unit, a pre-processing unit and a post-processing unit such as a heating and cooling unit, and a conveying device. That is, the number, kind, layout, and the like of these respective cells can be changed as appropriate.

[ developing processing Unit (substrate processing apparatus) ]

Next, the development processing unit (substrate processing apparatus) U1 is described in further detail. The developing process unit U1 performs a process of discharging the processing liquid onto the front side Wa of the wafers W one by one for the plurality of wafers W. As shown in fig. 4, the developing process unit U1 includes a rotary holding portion 20, a lifting device 22, and a process liquid supply portion 24.

The spin holding portion 20 includes a main body portion 20a having a power source such as an electric motor built therein, a rotation shaft 20b extending vertically upward from the main body portion 20a, and a chuck 20c provided at a distal end portion of the rotation shaft 20 b. The main body 20a rotates the rotary shaft 20b and the chuck 20c by a power source. The chuck 20c supports the center portion of the wafer W, and holds the wafer W substantially horizontally by suction, for example. That is, the rotary holding unit 20 rotates the wafer W around a central axis (vertical axis) perpendicular to the front surface Wa of the wafer W in a state where the posture of the wafer W is substantially horizontal. As shown in fig. 4, the rotary holding portion 20 rotates the wafer W, for example, clockwise when viewed from above.

The lifting device 22 is attached to the rotation holding portion 20 and lifts the rotation holding portion 20. Specifically, the lifting device 22 lifts and lowers the rotary holder 20 (chuck 20c) between a raised position (delivery position) for delivering and receiving the wafer W between the transfer arm a5 and the chuck 20c and a lowered position (development position) for performing the liquid processing.

A cup 30 is provided around the rotation holding portion 20. When the wafer W rotates, the processing liquid supplied to the front side Wa of the wafer W is thrown around and falls, but the cup 30 functions as a container for receiving the falling processing liquid. The cup body 30 includes: an annular bottom plate 31 surrounding the rotation holding portion 20; a cylindrical outer wall 32 projecting vertically upward from the outer edge of the bottom plate 31; and a cylindrical inner wall 33 projecting vertically upward from the inner edge of the bottom plate 31.

The entire portion of the outer wall 32 is located outside the wafer W held by the chuck 20 c. The upper end 32a of the outer wall 32 is located above the wafer W held by the rotation holding portion 20 at the lowered position. The portion of the outer wall 32 on the upper end 32a side becomes an inclined wall portion 32b inclined inward as going upward. The entire inner wall 33 is located inward of the peripheral edge of the wafer W held by the chuck 20 c. The upper end 33a of the inner wall 33 is located below the wafer W held by the rotation holding portion 20 located at the lowered position.

A partition wall 34 that protrudes vertically upward from the upper surface of the bottom plate 31 is provided between the inner wall 33 and the outer wall 32. That is, the partition wall 34 surrounds the inner wall 33. A liquid discharge hole 31a is formed in a portion between the outer wall 32 and the partition wall 34 in the bottom plate 31. The drain pipe 35 is connected to the liquid discharge hole 31 a. A gas discharge hole 31b is formed in a portion between the partition wall 34 and the inner wall 33 in the bottom plate 31. The gas discharge hole 31b is connected to the exhaust pipe 36.

The inner wall 33 is provided with an umbrella portion 37 extending outward beyond the partition wall 34. The processing liquid thrown outward from the wafer W and dropped is guided between the outer wall 32 and the partition wall 34, and is discharged from the liquid discharge hole 31 a. Gas generated from the processing liquid or the like enters between the partition wall 34 and the inner wall 33, and the gas is discharged from the gas discharge holes 31 b.

The upper part of the space surrounded by the inner wall 33 is closed by a partition plate 38. The main body portion 20a of the rotary holding portion 20 is located below the partition plate 38. The chuck 20c is located above the partition plate 38. The rotary shaft 20b is inserted into a through hole formed in the center of the partition plate 38.

As shown in fig. 4, the processing liquid supply unit 24 includes a supply source 24a of the processing liquid, a head 24c, a moving body 24d, and an imaging unit 26. The supply source 24a includes a storage container, a pump, a valve, and the like for the processing liquid. The processing liquid is, for example, a cleaning liquid (rinse liquid) or a developing liquid. The cleaning liquid is, for example, pure Water or DIW (Deionized Water). The head 24c is connected to the supply source 24a via a supply pipe 24 b. The head 24c is positioned above the front surface Wa of the wafer W when the processing liquid is supplied. The liquid nozzle N provided in the head 24c is opened downward so as to face the front surface Wa of the wafer W. Therefore, the head 24c receives a control signal from the control unit CU, and discharges the processing liquid supplied from the supply source 24a from the liquid nozzle N to the front surface Wa of the wafer W.

The moving body 24d is connected to the head 24c via an arm 24 e. The moving body 24d receives a control signal from the control unit CU and moves on a guide rail (not shown) in a horizontal direction (for example, the X-axis direction). Thus, in the discharging process of discharging the processing liquid from the discharge port Na of the liquid nozzle N toward the front side Wa of the wafer W, the head portion 24c moves horizontally in the radial direction of the wafer W on a straight line which is above the wafer W at the lowered position and which is orthogonal to the central axis of the wafer W. The moving body 24d receives a control signal from the control unit CU, and moves the arm 24e up and down. Thereby, the head 24c moves in the vertical direction to approach or separate from the front side Wa of the wafer W.

As shown in fig. 4, the imaging unit 26 is provided near the distal end of the head 24c and moves together with the head 24 c. The imaging unit 26 images the discharge port Na portion of the liquid nozzle N. The captured image captured by the imaging unit 26 is sent to the control unit CU2 of the control device CU. The control unit CU2 performs image processing on the received captured image, and acquires information such as the presence or absence of an attached matter near the discharge opening Na of the liquid nozzle N and the amount of the attached matter. The adherent substance in the present embodiment may be, for example, a liquid droplet or a solid substance (a substance obtained by solidifying or crystallizing a treatment liquid, a foreign substance), or the like. The control unit CU2 determines an abnormality of the liquid nozzle N based on the result of the deposit near the discharge port Na of the liquid nozzle N, and performs cleaning of the liquid nozzle N in the case of the abnormality. In addition, measures for abnormality (for example, issuing an alarm, notifying an abnormality, and the like) are performed when an abnormality persists.

The imaging unit 26 is configured to be able to image the vicinity of the discharge opening Na of the liquid nozzle N over the entire circumference thereof. The vicinity of the discharge port Na of the liquid nozzle N is a region to which the processing liquid discharged from the discharge port Na can adhere. The region where the processing liquid adheres can be changed according to the discharge rate (discharge amount per unit time) of the processing liquid, the rotation speed of the wafer W, and the like. Therefore, a portion to which the treatment liquid can adhere during normal operation can be treated as the vicinity of the release port Na. Specifically, for example, the thickness is about 0.5mm to several mm from the lower end of the release opening Na.

When the processing liquid is discharged from the discharge port Na, if the processing liquid remains attached to the lower end portion of the discharge port Na or the peripheral edge thereof, the attached matter may flow toward the wafer W together with the processing liquid at the initial stage of discharge when the processing liquid is discharged again thereafter. When the supply amount of the processing liquid to the wafer W is large, the processing liquid in the initial stage of release is discharged from the wafer W, and therefore the deposits are also discharged from the wafer W. However, when the supply amount of the processing liquid is small, the processing liquid in the initial stage of the release may remain on the wafer W, and the deposits may remain on the wafer W. In such a case, the deposit may become a foreign substance on the wafer W, which may affect the processing accuracy of the substrate. From the above-described viewpoint, the imaging unit 26 images the entire circumference of the liquid nozzle N in the vicinity of the discharge port Na. The imaging unit 26 may be configured to image the deposits around the entire periphery in the vicinity of the discharge opening Na. Therefore, the image acquired by the imaging unit 26 may include an image of the entire circumference at least in a part near the discharge opening Na. The images taken around the entire circumference in the vicinity of the discharge port Na of the image pickup liquid nozzle N may not be taken at the same time, or may be combined from a plurality of images taken with a slight time difference. As described above, the deposits adhering to the vicinity of the discharge port Na mainly originate from the treatment liquid discharged from the liquid nozzle N, and after a certain time has elapsed, the state thereof may change due to drying, moisture absorption, or the like. The imaging unit 26 may be configured to: the images of the entire week are acquired by capturing a plurality of images with a time difference (for example, several seconds to several minutes) of such a degree that the state of the attached matter does not change.

In fig. 4, the imaging unit 26 is schematically illustrated, but the configuration of the imaging unit 26 for imaging the entire circumference is not particularly limited. Fig. 6 to 8 are diagrams illustrating a configuration example of the imaging unit 26.

Fig. 6 (a) shows a configuration in which the imaging unit 26 is constituted by a plurality of cameras 27 and the entire periphery of the vicinity of the discharge opening Na of the liquid nozzle N is imaged. Fig. 6 (a) shows an example in which 3 cameras 27 are arranged, but the number of imaging units 26 is not particularly limited. By arranging the plurality of imaging units 26 so that the entire periphery in the vicinity of the discharge port Na can be imaged from different directions, it is possible to acquire an image about the entire periphery in the vicinity of the discharge port Na of the liquid nozzle N. When 3 cameras 27 are arranged, for example, in a plan view, the 3 cameras 27 can be arranged uniformly in the circumferential direction such that the angle formed by the line connecting the adjacent cameras 27 and the discharge port Na of the liquid nozzle N and the line connecting the own camera and the discharge port Na is 120 °. This allows the entire circumference around the discharge opening Na to be uniformly photographed by the 3 cameras 27. The plurality of cameras 27 may be arranged on the same horizontal plane (XY plane), but may be arranged at different height positions in the vertical direction (Z axis direction), for example. The camera 27 may be provided on the treatment liquid supply unit 24, or may be attached to the outer wall 32 of the cup member 30. That is, the position (component) of the developing process unit U1 where the camera 27 is attached is not particularly limited.

Fig. 6 (b) shows a state where the imaging unit 26 is constituted by 1 camera 27 and 1 mirror 28. In the case of such a configuration, the camera 27 captures an image of the vicinity of the discharge opening Na of the liquid nozzle N in the mirror 28. The mirror 28 is disposed below the discharge opening Na (in the negative Z-axis direction), for example, as shown in fig. 6 (b), and the angle of the reflecting surface thereof is adjusted in accordance with the position of the camera 27. On the other hand, the camera 27 is disposed opposite to the reflection surface of the mirror 28. Thus, the camera 27 can capture an image of the vicinity of the discharge opening Na reflected by the mirror 28. Further, by adopting the configuration using the reflecting mirror 28, the vicinity of the discharge port Na on the side of the blind spot can be photographed from the camera 27, and an image of the entire circumference in the vicinity of the discharge port Na of the liquid nozzle N can be acquired. In addition, the arrangement of the camera 27 and the mirror 28 can be changed as appropriate.

Fig. 6 (c) shows a state where the imaging unit 26 is constituted by 1 camera 27. The camera 27 is disposed just below the discharge port Na of the liquid nozzle N (in the Z-axis negative direction). In the case of such a configuration, the camera 27 can photograph the entire circumference of the lower end of the discharge port Na of the liquid nozzle N at one time. That is, even in the case of the configuration shown in fig. 6 (c), imaging can be performed around the entire circumference in the vicinity of the discharge opening Na. In the case of a shape in which the tip becomes thinner as it goes to the discharge port Na as in the liquid nozzle N shown in fig. 6 and the like, the camera 27 shown in fig. 6 (c) can photograph not only the lower end of the discharge port Na but also an inclined portion above it. As shown in fig. 6 (c), the camera 27 may be disposed directly below the discharge port Na, and an image of the side surface of the liquid nozzle N near the discharge port Na may be captured by the camera 27 using the mirror 28.

Fig. 7 shows an example of the arrangement of the camera 27 and the mirror 28, in which the camera 27 is attached to an arm 24e connected to the head 24c, and the mirror 28 is arranged below the liquid nozzle N. The height position of the arm 24e is not limited to the configuration of fig. 4, and can be changed as appropriate by changing the configuration of other members, for example, by changing the configuration of the head 24 c. Instead of the mirror 28, a substrate (bare wafer) having a flat surface held by the chuck 20c may be used. In this case, the camera 27 is configured to capture an image of the vicinity of the discharge opening Na of the liquid nozzle N on the bare wafer.

Fig. 8 shows another example of the arrangement of the camera 27 and the mirror 28, in which the camera 27 is attached to an arm 24e connected to the head 24c, and the mirror 28 is arranged around the liquid nozzle N. Fig. 8 (a) is a side view of the above-described structure, and fig. 8 (b) is a view schematically showing a positional relationship between the liquid nozzle N, the camera 27, and the mirror 28 when viewed from above. In the example shown in fig. 8, the installation position of the camera 27 is the same as that of the example shown in fig. 7, but the arrangement of the reflecting mirror 28 is different. Specifically, the mirror 28 is disposed so that the outer wall of the side surface of the liquid nozzle N, which forms a blind spot with respect to the camera 27, is reflected on the mirror 28. Therefore, the camera 27 can also take an image of the blind spot by taking an image of the side surface of the liquid nozzle N projected on the mirror 28. With such a configuration, the camera 27 can perform imaging of the entire circumference of the side surface of the liquid nozzle N by one-time imaging.

As described above, the configuration of the imaging unit 26 is not particularly limited, and various configurations can be adopted. The above-described configuration examples may be combined. Further, the camera 27 having a moving mechanism that can change its position with respect to the liquid nozzle N may be used as the image pickup section 26. In addition, when the camera 27 is disposed in the vicinity of the discharge opening Na, the configuration of each part can be appropriately adjusted so that the camera 27 and the mechanism for supporting the camera 27 do not interfere with the operation of each part of the development processing unit U1.

[ method of inspecting nozzle ]

Next, a flow of a method for inspecting the discharge port Na of the liquid nozzle N in the developing process unit U1 will be described with reference to fig. 9 to 16. Fig. 9 is a flowchart illustrating a series of steps of the inspection method. Fig. 10 and 13 are flowcharts illustrating a flow related to image processing and evaluation of adhesion state, and fig. 11, 12, 14 to 16 are diagrams illustrating examples of images used when the above-described flow is performed.

First, the control unit CU2 of the control unit CU executes step S01. In step S01, a reference image for evaluating the state of the attached matter in the vicinity of the discharge opening Na of the liquid nozzle N is acquired. The reference image is an image of the vicinity of the discharge opening Na of the liquid nozzle N in a state where no adhering substance is attached, and corresponds to an image of the entire circumference of the vicinity of the discharge opening Na of the liquid nozzle N acquired at the time of inspection. The control unit CU2 controls the imaging unit 26 to acquire a reference image in the vicinity of the discharge opening Na of the liquid nozzle N. The acquired reference image may be stored in the storage unit CU 1.

Next, the control unit CU2 executes step S02. In step S02, the control unit CU2 acquires an inspection image of the entire circumference in the vicinity of the discharge port Na of the liquid nozzle N (image acquisition control). The inspection image is an image to be evaluated for the attached matter. The control unit CU2 controls the imaging unit 26 to acquire an inspection image of the vicinity of the discharge opening Na of the liquid nozzle N. The timing to execute step S02 may be a preset timing (for example, after the process on the wafers W in the batch unit is finished). Step S02 may be executed based on the result of evaluation of the processed wafer W or the like in the developing unit U1. In addition, when a plurality of images are combined to obtain an image of the entire circumference in the vicinity of the discharge opening Na of the liquid nozzle N, a series of the plurality of images may be processed as one inspection image. The acquired inspection image may be stored in the storage unit CU 1.

Next, the control unit CU2 executes step S03. In step S03, the control unit CU2 performs image processing (evaluation control) related to evaluation of the attached matter using the reference image acquired in step S01 and the inspection image acquired in step S02. Next, the control unit CU2 executes step S04. In step S04, evaluation (evaluation control) is performed on the adhesion state of the adhering matter based on the image processed in step S03. The above-described steps S03 and S04 will be described later.

Next, the control unit CU2 executes step S05. In step S05, it is determined whether or not the liquid nozzle N is abnormal as a result of the evaluation of the adhesion state in step S04 (determination control). The determination of whether or not there is an abnormality at this stage is a determination of whether or not it is appropriate to process the wafer W using the liquid nozzle N as it is. Therefore, when it is determined that there is no abnormality, it is determined that there is no operation to be performed on the liquid nozzle N based on the inspection result of the liquid nozzle N, and a series of processing is ended.

If it is determined in step S05 that there is an abnormality, control unit CU2 executes step S06. In step S06, when it is determined that there is an abnormality in the present determination, it is determined whether or not an operation (determination control) to be performed on the liquid nozzle N is necessary, such as forced stop (abnormal stop) due to an abnormality in the apparatus. When it is determined that there is an abnormality, the adhesion of the deposits near the discharge opening Na of the liquid nozzle N is detected, but in such a case, the vicinity of the discharge opening Na of the liquid nozzle N is usually cleaned to cope with the abnormality. However, for example, when it is determined that some countermeasure other than cleaning of the nozzles is necessary such as repeated abnormality, it is determined that abnormal stop is necessary. In this case, the control unit CU2 executes step S07. That is, in step S07, the control unit CU2 performs forcible stop of the substrate process in the developing process unit U1. In addition, in fig. 8, the case where the determination as to whether or not the abnormal stop is necessary and the abnormal stop are performed has been described, but the abnormal stop may be not performed only by the notification of the alarm. In step S06, it may be determined whether or not to perform any of abnormal stop and alarm notification.

If it is determined in step S06 that the abnormal stop is not necessary, control unit CU2 executes step S08. In step S08, the vicinity of the discharge port Na of the liquid nozzle N is cleaned (determination control/cleaning control). The control unit CU2 controls the developing unit U1 to perform a process related to cleaning of the liquid nozzle N. Further, the method of cleaning the liquid nozzle N in step S08 may be changed based on the evaluation result of the adhesion state. This point will be explained later.

[ detailed procedure from image processing to abnormality judgment ]

Next, a specific flow of determining whether or not there is an abnormality in the vicinity of the discharge port Na of the liquid nozzle N will be described with reference to fig. 10 to 12. The flow described here is one mode of the specific flow of steps S03 to S06 in fig. 9.

First, the control unit CU2 executes step S11. In step S11, the control unit CU2 calculates a difference from the reference image and the inspection image stored in the storage unit CU 1. By calculating the difference, it is possible to grasp, from the luminance value, how much each pixel in the inspection image has changed from the reference image. Most of the portion where the luminance value differs from 0, which is the change of the inspection image from the reference image, is affected by the attachment of the attached matter. That is, by performing processing for creating an image relating to the difference, the region of the attached matter can be estimated.

The control unit CU2 executes step S12. In step S12, the control unit CU2 calculates an average value of the luminance values of the pixels in the difference image. That is, the average value of the luminance values of all pixels included in the difference image is calculated.

The control unit CU2 executes step S13. In step S13, an abnormality determination is made based on the average value of the luminance values calculated in step S12. Specifically, when the average value is equal to or greater than the threshold value, it is determined that an abnormality exists in the vicinity of the discharge port Na of the liquid nozzle N. When it is determined in step S13 that there is an abnormality, the control unit CU2 performs further determination based on the flow shown in fig. 9 and performs control such as abnormal stop and cleaning.

A specific example will be described with reference to fig. 11. Fig. 11 shows an example of an image obtained by imaging the vicinity of the discharge port Na of the liquid nozzle N from a downward inclination direction. In fig. 11, an image of 307200 pixels in total of 480 pixels in vertical direction × 640 pixels in horizontal direction is used. Fig. 11 (a) corresponds to a reference image of the vicinity of the discharge opening Na of the liquid nozzle N. On the other hand, fig. 11 (b) is an image corresponding to the inspection image, and is an image showing a state in which almost no attached matter is present. Fig. 11 (c) shows the result of obtaining such a difference between 2 images. The image shown in fig. 11 (c) is a monochrome image in which the difference in luminance value (pixel value) among the pixels of 2 images is indicated at the position corresponding to each pixel. In the case where the reference image and the inspection image are color images, the difference between the luminance values may be calculated after the gradation. In the case of a color image, fig. 11 (c) shows the luminance values (0 to 255) of the respective pixels as a gray scale, and shows white as the luminance value increases. Fig. 11 (c) shows a state where brightness adjustment is performed on the entire image for reference. In addition, when the reference image and the inspection image are color images, a method of calculating a pixel value of each pixel by a method different from the gradation may be used.

When the image in which the adhering matter is hardly present is the inspection image as in the inspection image shown in fig. 11 (b), the number of pixels having luminance values in the difference image is considerably small as shown in fig. 11 (c), and as a result, the average value of the luminance values becomes small. In the example shown in fig. 11 (c), the average value of the luminance values is 2.95. On the other hand, fig. 11 (d) is an image corresponding to an inspection image different from fig. 11 (b), and is an image showing a state where an attached matter is present in the vicinity of the tip of the discharge port Na of the liquid nozzle N. When the difference between the 2 images is calculated, as shown in fig. 11 (e), a pixel having a luminance value of a certain degree (appearing white) exists in the region where the attached matter is considered to be attached. In this case, the average value of the luminance values becomes large. In the example shown in fig. 11 (e), the average value of the luminance values is 2.95. In this way, the average value of the luminance values of the difference image using the reference image changes according to the adhesion state of the adhering matter. Therefore, when the average value is larger than the predetermined threshold value, it can be determined that the deposit adheres to the vicinity of the discharge port Na of the liquid nozzle N and the abnormality exists. Note that fig. 11 (e) shows a state where brightness adjustment is performed on the entire image for reference.

A specific example different from that of fig. 11 will be described with reference to fig. 12. Fig. 12 shows an example of an image obtained by imaging the vicinity of the discharge port Na of the liquid nozzle N from directly below the discharge port Na. In fig. 12, an image of 307200 pixels in total of 640 pixels in length by 480 pixels in width is used. Fig. 12 (a) corresponds to a reference image of the vicinity of the discharge opening Na of the liquid nozzle N. On the other hand, fig. 12 (b) is an image showing a state where the attached matter is present in the vicinity of the tip of the discharge port Na of the liquid nozzle N. Fig. 12 (c) shows the result of calculating the difference between the 2 images. Fig. 12 (c) is an image showing the result of calculating the difference luminance value by the same method as in fig. 11 (c) and (e). Fig. 12 (c) also shows a state where brightness adjustment of the entire image is performed. As shown in fig. 12 (c), in the region where the attached matter is considered to be attached, there is a pixel having a luminance value of a certain degree (appearing white). In this case, since the average value of the luminance values of all the pixels is considered to be increased to some extent, when the average value is larger than a predetermined threshold value, it is determined that an attached matter is attached to the vicinity of the discharge port Na of the liquid nozzle N and an abnormality is present.

In the difference image shown in fig. 12 (c), the images of the adhering substances adhering to the inner wall side and the outer wall side of the discharge port Na of the liquid nozzle N can be distinguished from each other. That is, in the region corresponding to the end face of the lower end of the discharge opening Na, since both the reference image and the inspection image have the same degree of luminance, the luminance is 0 or close to 0 in the difference image. On the other hand, as shown in fig. 12 (b), the adhered matter in the inspection image is more conspicuous than the reference image, on the inner side of the inner wall surface and on the outer side of the outer wall surface. Therefore, as shown in fig. 12 (c), a region having a large luminance value is observed in each region in the difference image.

In the case of the example shown in fig. 12, as described above, the attachment on the inner wall and the attachment on the outer wall can be distinguished from each other. Therefore, when the evaluation of the deposit near the discharge port Na of the liquid nozzle N is performed using such an image, the deposit on the inner wall side and the deposit on the outer wall side can be distinguished and evaluated. In addition, as in the example shown in fig. 12, when the resolution of an image obtained by imaging the vicinity of the discharge port Na of the liquid nozzle N is high, the characteristics of the adhering matter are reflected in the image. Therefore, the information on the characteristics of the attached matter can be acquired from the inspection image or the difference image, and the type of the attached matter can be specified.

Therefore, a specific flow when determining whether or not there is an abnormality in the vicinity of the discharge port Na of the liquid nozzle N based on the evaluation of the attached matter by distinguishing the attachment position of the attached matter, the evaluation of the type of the attached matter, and the like will be described with reference to fig. 13 to 16. The flow described here is one mode of the specific flow of steps S03 to S06 in fig. 9.

Fig. 14 to 16 show a specific example of an image obtained by imaging the lower end of the discharge port Na of the liquid nozzle N, as in fig. 12. However, the same procedure can be performed also in the case where an image obtained by imaging the discharge port Na of the liquid nozzle N from obliquely below as described in fig. 11 is used as an inspection image. In addition, the same flow can be performed even when an image obtained by imaging the entire circumference of the side surface near the discharge port Na of the liquid nozzle N is used as an inspection image. However, depending on the orientation of the liquid nozzle N in the inspection image, it may be difficult to detect deposits on the lower surface of the discharge port Na of the liquid nozzle N, and depending on the orientation of the liquid nozzle N in the inspection image, a portion to be subjected to abnormality determination (a side surface, a lower end, or the like of the liquid nozzle N) may change.

First, the control unit CU2 executes step S21. In step S21, the control unit CU2 calculates a difference from the reference image and the inspection image stored in the storage unit CU 1. This step is the same as step S11.

Next, the control unit CU2 executes step S22. In step S22, the control unit CU2 estimates the position of the deposit near the discharge opening Na of the liquid nozzle N based on the nozzle shape information near the discharge opening Na of the liquid nozzle N. The nozzle shape information is information for specifying the shape of the liquid nozzle N. In the present embodiment, the outline of the lower end portion of the liquid nozzle N, that is, the outline of the lower end portion, is the nozzle shape information, but information for specifying the shape of the other portion may be the nozzle shape information, for example, depending on the orientation of the liquid nozzle N in the inspection image. That is, the nozzle shape information is information that can specify the shape of the nozzle in a state where no adhering substance is attached.

As shown in fig. 12 (c), in the difference image between the reference image and the inspection image, the contour of the lower end of the discharge port Na of the liquid nozzle N can be specified. That is, as shown in fig. 14 (a), the outline of the lower end of the discharge port Na of the liquid nozzle N, that is, the boundary portion with the inner wall and the boundary portion with the outer wall of the lower end surface can be specified from the differential image. Instead of acquiring the nozzle shape information from the difference image, the storage unit CU1 of the control unit CU may hold corresponding information in advance. The image of the vicinity of the discharge opening Na of the liquid nozzle N captured by the imaging unit 26 is basically determined by the imaging position as described above. Therefore, the nozzle shape information of the discharge opening Na of the liquid nozzle N included in the inspection image is substantially unchanged, and the position of the lower end of the discharge opening Na of the liquid nozzle N in the inspection image may be previously maintained.

When the nozzle shape information is used as described above, it can be estimated whether the region to which the attachments are attached, which is the region having a high luminance value in the difference image, is located on the inner wall side or the outer wall side of the liquid nozzle N. That is, the attachment position of the attached matter can be estimated using the nozzle shape information included in the difference image. In the present embodiment, the estimation of the attachment position of the attached matter at this stage will be described with respect to a case where the attachment position is either the inner wall side or the outer wall side. However, as a more detailed attachment position, for example, it may be configured to estimate in which direction the attachment is present, or a position of a distance from the discharge port Na of the liquid nozzle N, or the like, with reference to the center of the liquid nozzle N. Depending on which side the inspection image is taken from, the attachment position (positional relationship in the vertical direction, radial direction, or the like) that can be estimated from the image may vary.

Next, the control unit CU2 executes step S23. In step S23, the control unit CU2 evaluates the amount of adhering substance based on the number of pixels of the adhering substance photographed at each adhering position. Fig. 14 (b) shows an example in which only a region that is considered to capture an adhering substance on the outer wall side is extracted after binarization processing is performed on the image shown in fig. 12 (c) with reference to a predetermined threshold value. Fig. 14 (c) shows an example in which only a region that is considered to have been imaged with an adherent on the inner wall side is extracted after binarization processing is performed on the image shown in fig. 12 (c) with reference to a predetermined threshold value. In this way, by extracting the region where the deposits on the outer wall side/inner wall side are captured after the binarization processing, the number of pixels (the number of pixels) of the captured deposits on the outer wall side/inner wall side of the liquid nozzle N can be calculated. For example, in the example shown in fig. 14 (b), the number of pixels on which the attached object is imaged on the outer wall side can be 12649 pixels. In the example shown in fig. 14 (c), the number of pixels on which the attached matter is imaged on the inner wall side can be 5426 pixels. In this way, the amount of adhesion of the adhering substance can be evaluated based on the number of pixels that are imaged for the adhering substance, i.e., the area that is imaged for the adhering substance. The adhesion amount thus calculated can be used as information for determining whether or not there is an abnormality.

Next, the control unit CU2 executes step S24. In step S24, control unit CU2 evaluates the type of adhering matter. As described above, the types of the adhering substances are roughly classified into liquid (liquid droplets) and solid (solid substance). In step S24, the control unit CU2 distinguishes the 2 categories based on the inspection image or the difference image.

An example of a flow for identifying the type of the attached matter will be described with reference to fig. 15. Fig. 15 (a) is an inspection image obtained by imaging a state in which liquid droplets are attached to the outer wall side near the discharge port Na of the liquid nozzle N. Fig. 15 (b) is an image obtained by binarizing the inspection image shown in fig. 15 (a) with reference to a predetermined threshold value. On the other hand, fig. 15 (c) is an inspection image obtained by imaging a state in which a solid material is attached to the outer wall side in the vicinity of the discharge port Na of the liquid nozzle N. Fig. 15 (d) is an image obtained by binarizing the inspection image shown in fig. 15 (c) with reference to a predetermined threshold value.

As can be seen from comparison between fig. 15 (a) and 15 (c), the appearance of the captured image changes between the case where the liquid droplets are deposited and the case where the solid matter is deposited. Specifically, when a droplet is deposited, the profile of the deposited material is gentle, and the light emission pattern is uniform, so that the shape of the deposited material is gentle in the image. On the other hand, when a solid matter adheres, minute irregularities may remain on the outer shape of the adhered matter (naturally, the shape may vary depending on the solid matter), so that light scattering becomes sparse, and irregularities clearly remain even on an image. The above-described difference can be grasped in the binarized images shown in fig. 15 (b) and 15 (d). Therefore, the appearance (unevenness) of the attached matter can be estimated using the binarized image in which the attached matter amount is evaluated, and it can be determined whether the attached matter is liquid or solid. The type of the adhering matter may be determined directly from the inspection image (images shown in fig. 15 (a) and (c)) instead of the binarized image. In addition, when the outer shape (unevenness) is estimated, polar coordinate development may be performed.

Instead of performing the determination based on the irregularities of the external shape of the attached matter as described above, the determination may be performed based on the size (number of pixels) of the region where 1 attached matter is imaged, for example. For example, if the droplet has no certain size, the droplet does not exist alone, and therefore it can be estimated that the area where the attached matter is captured in the image in which the droplet is captured becomes large to some extent. On the other hand, the solid may be smaller than the liquid droplet, or may exist alone. In this case, it may be determined that a droplet is present in a region larger than a predetermined threshold value and a solid object is present in the other region based on the size (number of pixels) of the region estimated to be continuous in which 1 attached object is captured. As described above, the method of determining the type of the deposit in the vicinity of the discharge port Na of the liquid nozzle N from the inspection image or an image processed from the inspection image (for example, binarized image) is not particularly limited, and various methods can be applied.

Next, the control unit CU2 executes step S25. In step S25, the control unit CU2 determines whether or not there is an abnormality based on the various information obtained in steps S23 and S24. For example, by executing step S23, information on the amount of adhering matter can be obtained in control unit CU 2. Further, by executing step S24, the control unit CU2 can obtain information about the type of the attached matter. The use of this information can be employed to determine whether an abnormality exists.

The criterion for determining whether or not there is an abnormality based on the amount of adhering matter may simply be the number of pixels of the pixel where the adhering matter is captured, but is not limited to this. For example, whether or not there is an abnormality may be determined based on the magnitude of the luminance value (pixel value) of the pixel where the attached matter is imaged. In addition, how the attached matter is attached may be included in the criterion for determining whether or not there is an abnormality. Fig. 16 is a diagram illustrating an example of a case in which the "state" in which the attached matter is attached is also considered. In fig. 16, 2 reference lines L1 and L2 for determining whether there is an abnormality are added to the image obtained by extracting the region where the extraneous matter is captured on the outer wall shown in fig. 14 (b). Reference lines L1 and L2 are circles having different distances from the outer wall with respect to the center of the discharge opening Na of the liquid nozzle N. That is, the reference line L1 is a line 100 μm outside the outer wall, and the reference line L2 is a line 50 μm outside the outer wall. The following may be used: the reference lines L1 and L2 are provided in advance, and whether or not there is an abnormality is determined based on the positional relationship between the reference lines L1 and L2 and the pixels where the attached matter is captured. For example, when the attached matter protrudes outward beyond the reference line L1, it can be determined that abnormal stop is necessary. In addition, the following method may be adopted: if the deposit does not protrude outside the reference line L1 but protrudes outside the reference line L2, it is determined that there is an abnormality and a warning is issued. In addition, the following method may be adopted: when the number of adhering objects (the number of pixels of the area where the adhering objects are captured) protruding outward from the reference line L1 or the reference line L2 exceeds a predetermined amount, it is determined that the object is abnormal. In this way, the reference lines L1 and L2 may be used as a reference for determining whether or not there is an abnormality.

Next, the control unit CU2 executes step S26. In step S26, if it is determined from the result of the determination of the abnormality that cleaning of the liquid nozzle N is necessary, the control unit CU2 selects a cleaning method according to the determination result and executes the cleaning.

Fig. 17 shows an example of a flow of determination in the control unit CU2 regarding selection of a specific cleaning method. First, the control unit CU2 executes step S31. In step S31, the control unit CU2 determines whether or not dirt (deposits) is present on the inner wall side near the discharge opening Na of the liquid nozzle N based on the result of the determination of the position of the deposits (step S22). As a result, when determining that the adhering substance is present on the inner wall side, the control unit CU2 executes step S32. That is, as step S32, control unit CU2 performs cleaning of liquid nozzle N in such a manner that the inner wall of liquid nozzle N can be cleaned. In this case, the outer wall can be cleaned together with the cleaning of the inside of the liquid nozzle N. On the other hand, when determining that there is no adhering substance on the inner wall side, the control unit CU2 executes step S33. That is, the control unit CU2 cleans the nozzle tip. The cleaning of the nozzle tip is a method of mainly cleaning the outer wall of the nozzle, and is a method of performing the cleaning of the inner wall with a smaller number of steps. In this way, a method of changing the cleaning method according to the position of the deposit can be adopted. Further, a predetermined cleaning method may be executed when cleaning is necessary, without selecting a cleaning method according to the position where the attached matter is attached (step S26).

In the above embodiment, 2 flows are described with reference to fig. 10 and 13. However, the determination as to whether or not the liquid nozzle N is abnormal may be performed by the control unit CU2 simultaneously executing the flows described in both fig. 10 and 13, or may be performed by only one of them.

[ Effect ]

In accordance with the developing process unit (substrate processing apparatus) U1 and the nozzle inspection method described above, the adhesion state of the adhering substance to the discharge port Na of the liquid nozzle N was evaluated based on the inspection image obtained by imaging the vicinity of the discharge port Na of the liquid nozzle N over the entire circumference. More specifically, the area where the deposits are deposited on the liquid nozzle N is estimated, and the presence or absence of an abnormality is determined based on the result. In this way, evaluation is performed based on an image obtained by imaging the entire circumference in the vicinity of the discharge port Na of the liquid nozzle N, and it is determined whether or not there is an abnormality as one mode. Therefore, the possibility of the liquid nozzle N operating in a state where the deposits are deposited can be reduced, and therefore the deposition state of the deposits in the vicinity of the discharge opening Na of the nozzle can be evaluated more appropriately.

Conventionally, a technique of using an image when evaluating the state of a liquid nozzle for supplying a processing liquid in a substrate processing apparatus has been studied. However, in the case of a configuration in which evaluation is performed using an image obtained by imaging the liquid nozzle from one direction, if an attached matter is attached to a part that cannot be imaged in the image, the attached matter may not be noticed. In such a case, the abnormality determination of the liquid nozzle may be erroneously performed. However, since the amount of the processing liquid supplied to the substrate is large in the past as described above, there is a low possibility that the deposits falling on the surface of the substrate together with the processing liquid in the initial stage of discharge become a problem in the substrate processing. Therefore, even with the above configuration, there is a low possibility of a serious problem.

In contrast, in recent years, in the control of reducing the supply amount of the processing liquid to the substrate compared to the conventional liquid processing, which has been studied, a defect is caused in the liquid processing on the substrate when the deposit is mixed into the processing liquid at the initial stage of the release. Therefore, a technique for detecting the adhesion of the adhering substance to the nozzle with higher accuracy is required. According to the substrate processing apparatus and the nozzle inspection method described above, the evaluation of the adhesion of the adhering substance to the nozzle can be performed with higher accuracy than in the conventional art, and the presence or absence of an abnormality can be determined. Therefore, it is possible to cope with the control of the substrate processing in which the supply amount of the processing liquid is reduced.

Further, as described in the above embodiment, by determining the operation to be performed on the liquid nozzle based on the evaluation result, it is possible to perform appropriate treatment in accordance with the evaluation result, and it is possible to perform appropriate treatment in consideration of the abnormality of the liquid nozzle N and the like.

As described in the above embodiment, the adhesion state of the adhering substance is evaluated based on the pixel value or the number of pixels of the region where the adhering substance is captured in the inspection image, and whether or not there is an abnormality in the liquid nozzle N is determined based on the result. By adopting such a method, whether or not there is an abnormality can be evaluated from the adhesion state of the adhering matter. Therefore, the adhesion state of the adhering matter can be evaluated more appropriately by adopting such a method.

In the above embodiment, it is estimated whether the adhering substance adhering to the liquid nozzle N estimated from the inspection image is a liquid or a solid. By adopting such a method, it is possible to evaluate how strongly the adhering substance adheres to the vicinity of the discharge port Na of the liquid nozzle N, and the adhering state can be evaluated more appropriately.

In the above embodiment, by estimating the adhesion position of the adhering substance based on the inspection image, it is possible to evaluate with higher accuracy how much the adhering substance affects the process using the liquid nozzle N. In particular, depending on which of the inner wall side and the outer wall side of the liquid nozzle N the attached matter is attached to, the risk of the attached matter being discharged together with the processing liquid can also be changed. Therefore, by estimating which of the inner wall side and the outer wall side of the liquid nozzle N the deposit adheres to, the influence of the deposit on the substrate processing can be evaluated more appropriately.

In the above embodiment, the cleaning method of the liquid nozzle N is selected based on the evaluation result in the evaluation control. By adopting such a method, appropriate cleaning can be performed according to the adhesion state of the adhering matter. Therefore, the adhering portion can be appropriately removed from the liquid nozzle N.

While various exemplary embodiments have been described above, the present invention is not limited to the above exemplary embodiments, and various omissions, substitutions, and changes may be made. In addition, elements in different embodiments may be combined to form another embodiment.

For example, in the above-described embodiment, the case where the control unit CU2 of the control device CU performs control related to nozzle check is described. However, the functional units for performing control related to nozzle inspection may be collectively arranged in 1 apparatus, or may be arranged in a plurality of apparatuses in a distributed manner.

In addition, the shape of the liquid nozzle N and the discharge port Na can be appropriately changed. The configuration of the imaging unit 26 can be changed according to the shape of the discharge opening Na. In addition, the image used as the inspection image can be changed according to the shape of the liquid nozzle N.

The method of estimating the area where the attached matter is captured from the inspection image is not limited to the above embodiment. For example, in the above-described embodiment, the evaluation of the deposit on the lower end (lower surface) of the discharge port Na is not described with respect to the image captured directly below the discharge port Na of the liquid nozzle N. On the other hand, for example, the adhering substance at the lower end may be evaluated based on the distribution of the luminance values of the respective pixels in the inspection image. In the above-described embodiment, the case where the abnormality is determined based on the difference image generated using the reference image has been described, but a method not using the difference image may be employed. In addition, a method not using the reference image may be employed.

From the above description, various embodiments of the present invention have been described in the present specification for the purpose of explanation, and it is to be understood that various modifications may be made without departing from the scope and spirit of the present invention. Accordingly, the various embodiments disclosed in this specification are not to be taken in a limiting sense, and the true scope and spirit are given by the appended claims.

Description of the reference numerals

1 … … coating and developing device, 26 … … shooting part, 27 … … camera, 28 … … mirror, CU … … control device, CU1 … … storage part, CU2 … … control part, D … … display part, N … … liquid nozzle, Na … … discharge port, U1 … … developing processing unit (substrate processing device), W … … wafer (substrate), Wa … … front surface.

Claims

1. A substrate processing apparatus, comprising:

a liquid nozzle for discharging the processing liquid to the substrate below from the discharge port;

an imaging unit that images the entire circumference of the liquid nozzle in the vicinity of the discharge port; and

a control part for controlling the operation of the display device,

the control section executes:

an image acquisition control that acquires an inspection image of the entire circumference in the vicinity of the discharge port of the liquid nozzle, the inspection image being captured by the imaging unit; and

and an evaluation control for evaluating an adhesion state of the adhering substance to the discharge opening of the liquid nozzle based on the inspection image of the entire circumference in the vicinity of the discharge opening of the liquid nozzle.

2. The substrate processing apparatus according to claim 1, wherein:

the control unit further executes determination control that determines an operation to be executed on the liquid nozzle based on an evaluation result in the evaluation control.

3. The substrate processing apparatus according to claim 2, wherein:

the control unit estimates an area where an attached matter is attached to the liquid nozzle from the inspection image, and evaluates an attachment state of the attached matter to the discharge port of the liquid nozzle based on a pixel value of the estimated area,

the control unit determines whether or not there is an abnormality in the liquid nozzle based on the evaluation result in the determination control.

4. The substrate processing apparatus according to any one of claims 1 to 3, wherein:

the control unit estimates whether the attached matter attached to the liquid nozzle is a liquid or a solid based on an outline or a size of a region in which the attached matter attached to the liquid nozzle is captured, which is estimated from the inspection image, in the evaluation control.

5. The substrate processing apparatus according to any one of claims 1 to 4, wherein:

the control unit estimates an adhesion position of an adhering substance to the liquid nozzle based on the inspection image in the evaluation control.

6. The substrate processing apparatus according to claim 2, wherein:

the control unit selects a cleaning method of the liquid nozzle based on the evaluation result when it is determined that there is an abnormality in the liquid nozzle in the determination control.

7. A nozzle inspection method characterized by:

the nozzle inspection method is a nozzle inspection method for a substrate processing apparatus having a liquid nozzle for discharging a processing liquid from a discharge port to a substrate below,

the nozzle inspection method comprises:

acquiring an inspection image obtained by imaging the entire circumference of the vicinity of the discharge port of the liquid nozzle,

the adhesion state of the adhering substance to the discharge opening of the liquid nozzle is evaluated based on the inspection image of the entire circumference in the vicinity of the discharge opening of the liquid nozzle.

8. A computer-readable storage medium, characterized in that:

a program for causing an apparatus to execute the nozzle inspection method according to claim 7 is stored.