JP7313449B2 - SUBSTRATE PROCESSING APPARATUS, NOZZLE INSPECTION METHOD, AND STORAGE MEDIUM - Google Patents

Description

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

Japanese Unexamined Patent Application Publication No. 2002-200001 discloses a configuration for imaging an ejection opening portion of a liquid nozzle that supplies a processing liquid in a substrate processing apparatus and determining abnormality according to the state of foreign matter.

JP 2015-153913 A

The present disclosure provides a technology capable of more appropriately evaluating the state of adhering matter in the vicinity of the ejection port of a nozzle.

A substrate processing apparatus according to an aspect of the present disclosure includes: a liquid nozzle that ejects a processing liquid from an ejection port onto a substrate below; an imaging unit that captures an image of the entire periphery of the vicinity of the ejection port of the liquid nozzle; and a control unit. ,

Advantageous Effects of Invention According to the present disclosure, it is possible to more appropriately evaluate the state of adhering matter in the vicinity of the discharge port of a nozzle.

1 is a perspective view of a coating and developing system according to one exemplary embodiment; FIG. FIG. 2 is a diagram showing an example of a sectional view taken along line II-II of FIG. 1; FIG. 3 is a diagram showing an example of a cross-sectional view taken along line III-III of FIG. 2; It is an example of sectional drawing which shows a substrate processing apparatus. It is a figure which shows an example of the hardware constitutions of a substrate processing apparatus. It is a figure which shows the structural example of an imaging part. It is a figure which shows the structural example of an imaging part. It is a figure which shows the structural example of an imaging part. It is a flowchart which shows an example of the board|substrate inspection method by a substrate processing apparatus. It is a flowchart which shows an example of the board|substrate inspection method by a substrate processing apparatus. It is a figure which shows an example of the image used by a board|substrate inspection method. It is a figure which shows an example of the image used by a board|substrate inspection method. It is a flowchart which shows an example of the board|substrate inspection method by a substrate processing apparatus. It is a figure which shows an example of the image used by a board|substrate inspection method. It is a figure which shows an example of the image used by a board|substrate inspection method. It is a figure which shows an example of the image used by a board|substrate inspection method. FIG. 5 is a flow diagram showing an example of a procedure for selecting a substrate cleaning method;

Various exemplary embodiments are described below.

In one exemplary embodiment, a substrate processing apparatus includes: a liquid nozzle that ejects a processing liquid from an ejection port onto a substrate below; an imaging unit that captures an image of the entire periphery of the liquid nozzle in the vicinity of the ejection port; perform evaluation control;

According to the above-described substrate processing apparatus, the state of adherence of matter adhering to the ejection port of the liquid nozzle is evaluated based on the inspection image obtained by imaging the entire periphery in the vicinity of the ejection port of the liquid nozzle. In this way, the adhesion state of the adhering matter is evaluated based on the image obtained by capturing the entire circumference of the vicinity of the discharge port of the liquid nozzle, so the possibility of operating the liquid nozzle with the adhering matter attached can be reduced. Therefore, it is possible to more appropriately evaluate the state of adhering matter in the vicinity of the discharge port of the nozzle.

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

As described above, by configuring the control unit to determine the operation to be performed with respect to the liquid nozzle based on the evaluation result, it is possible to take appropriate measures according to the evaluation result, and to take appropriate measures in consideration of the abnormality of the liquid nozzle.

Further, in the evaluation control, the control unit may estimate an area of the deposit attached to the liquid nozzle from the inspection image, evaluate the state of attachment of the deposit to the ejection port of the liquid nozzle based on the pixel values of the estimated area, and determine whether or not there is an abnormality in the liquid nozzle based on the evaluation result in the determination control.

As described above, the state of adherence of adherents to the discharge ports of the liquid nozzles is evaluated based on the pixel values of the areas in which the adherents are imaged in the inspection image, and the presence or absence of an abnormality in the liquid nozzles is determined based on the evaluation results. With such a configuration, the presence or absence of abnormality can be evaluated substantially according to the amount of adhering matter, and the adherence state of the adhering matter can be evaluated more appropriately.

In the evaluation control, the control unit may estimate whether the substance adhering to the liquid nozzle is liquid or solid based on the outer shape or size of the imaged region of the substance adhering to the liquid nozzle estimated from the inspection image.

As described above, by estimating from the inspection image whether the adhering matter adhering to the liquid nozzle is liquid or solid, it is possible to evaluate how firmly the adhering matter is adhering in the vicinity of the discharge port of the liquid nozzle, and to more appropriately evaluate the adhering state.

In the evaluation control, the control unit may estimate a position where the adhering matter adheres to the liquid nozzle based on the inspection image.

As described above, by estimating the attachment position of the adhering matter, it is possible to more accurately evaluate how much the adhering matter affects the processing using the nozzle.

In the determination control, when it is determined that there is an abnormality in the liquid nozzle, the control section may select a cleaning method for the liquid nozzle based on the evaluation result.

As described above, by adopting a configuration in which the cleaning method for the liquid nozzle is selected based on the evaluation result of the evaluation control, it is possible to perform appropriate cleaning according to the adhesion state of the adhering matter, so that the adhering portion can be preferably removed from the nozzle.

In one exemplary embodiment, a nozzle inspection method relates to a substrate processing apparatus having a liquid nozzle that ejects a processing liquid from an ejection opening onto a substrate below, wherein an inspection image obtained by imaging the entire periphery of the vicinity of the ejection opening of the liquid nozzle is obtained, and the state of adhesion of matter adhering to the ejection opening of the liquid nozzle is evaluated from the inspection image of the entire periphery of the vicinity of the ejection opening of the liquid nozzle.

According to the above-described nozzle inspection method, the state of adherence of deposits to the discharge port of the liquid nozzle is evaluated based on an image obtained by capturing the entire circumference of the vicinity of the discharge port of the liquid nozzle, and the possibility of operating the liquid nozzle with the deposit adhered can be reduced. Therefore, it is possible to more appropriately evaluate the state of adhering matter in the vicinity of the discharge port of the nozzle.

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 are described in detail below with reference to the drawings. In addition, suppose that the same code|symbol is attached|subjected to the part which is the same or equivalent in each drawing. Hereinafter, in order to clarify the positional relationship, the X-axis, the Y-axis, and the Z-axis that are orthogonal to each other are defined as necessary, and the Z-axis positive direction is defined as the vertically upward direction.

[Operation of Coating/Developing Device]
First, an overview of the configuration of the coating/developing apparatus 1 shown in FIGS. 1 to 3 will be described. The coating/developing apparatus 1 applies a resist material to the surface Wa of the wafer (substrate) W to form a resist film before the exposure process by the exposure apparatus E1. The coating/developing apparatus 1 develops the resist film formed on the front surface Wa of the wafer W after the exposure process by the exposure apparatus E1. In this embodiment, the wafer W has a disc shape, but it may have a circular shape with a part cut away, or a wafer having a shape other than a circular shape such as a polygon may be used.

As shown in FIGS. 1 and 2, the coating/developing apparatus 1 includes a carrier block S1, a processing block S2, an interface block S3, a control unit CU functioning as control means for the coating/developing apparatus 1, and a display unit D capable of displaying the results of processing by the control unit CU. In this embodiment, the carrier block S1, processing block S2, interface block S3 and exposure apparatus E1 are arranged in series in this order.

The carrier block S1 has a carrier station 12 and a loading/unloading section 13, as shown in FIGS. A 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 loading and unloading the wafer W on one side surface 11a. The carrier 11 is detachably installed on the carrier station 12 so that the side surface 11a faces the loading/unloading section 13 side.

The loading/unloading section 13 has opening/closing doors 13a respectively corresponding to the plurality of carriers 11 on the carrier station 12, as shown in FIGS. When the opening/closing door on the side surface 11a and the opening/closing door 13a of the loading/unloading section 13 are opened at the same time, the inside of the carrier 11 and the inside of the loading/unloading section 13 communicate with each other. As shown in FIGS. 2 and 3, the carry-in/carry-out section 13 incorporates a transfer arm A1. The delivery arm A1 takes out the wafer W from the carrier 11 and delivers it to the processing block S2. The transfer arm A1 receives the wafer W from the processing block S2 and returns it into the carrier 11. FIG.

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

As shown in FIG. 2, the BCT block 14 incorporates 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 an antireflection film. The heating/cooling unit heats the wafer W using, for example, a hot plate, and then cools the wafer W using, for example, a cooling plate. Thus, the lower antireflection film is formed on the surface Wa of the wafer W. As shown in FIG.

As shown in FIG. 2, the COT block 15 incorporates a coating unit (not shown), a heating/cooling unit (not shown), and a transfer arm A3 for transferring the wafer W to these units. The coating unit applies a chemical solution (resist material) for forming a resist film onto the lower antireflection film. The heating/cooling unit heats the wafer W using, for example, a hot plate, and then cools the wafer W using, for example, a cooling plate. Thus, a resist film is formed on the lower antireflection film of the wafer W. As shown in FIG. The resist material may be positive or negative.

As shown in FIG. 2, the TCT block 16 incorporates 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 applies a chemical solution for forming an antireflection film onto the resist film. The heating/cooling unit heats the wafer W using, for example, a hot plate, and then cools the wafer W using, for example, a cooling plate. Thus, an upper antireflection film is formed on the resist film of the wafer W. As shown in FIG.

The DEV block 17, as shown in FIGS. 2 and 3, has a plurality of developing processing units (substrate processing apparatuses) U1 and a plurality of heating/cooling units (thermal processing section) U2. Further, the DEV block 17 incorporates a transfer arm A5 for transferring the wafer W to these units, and a transfer arm A6 for transferring the wafer W between the front and rear of the processing block S2 without passing through these units.

The development processing unit U1 develops the exposed resist film, as will be described later. The heating/cooling unit U2 heats the resist film on the wafer W, for example, by heating the wafer W with a hot plate. The heating/cooling unit U2 cools the heated wafer W using, for example, a cooling plate. The heating/cooling unit U2 performs heat treatments such as post-exposure baking (PEB) and post-baking (PB). PEB is a process of heating the resist film before development. PB is a process of heating the resist film after the development process.

As shown in FIGS. 1 to 3, a shelf unit U10 is provided on the carrier block S1 side of the processing block S2. Shelf unit U10 has a plurality of cells C30 to C38. The cells C30 to C38 are arranged vertically (Z-axis direction) between the DEV block 17 and the TCT block 16 . A lifting arm A7 is provided near the shelf unit U10. Elevating arm A7 carries wafer W between cells C30 to C38.

A shelf unit U11 is provided on the interface block S3 side of the processing block 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 in the vertical direction (Z-axis direction).

The interface block S3 is located between the processing block S2 and the exposure apparatus E1 and is connected to the processing block S2 and the exposure apparatus E1, respectively, as shown in FIGS. The interface block S3 incorporates a transfer arm A8, as shown in FIGS. Transfer arm A8 transfers wafer W from shelf unit U11 of processing block S2 to 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 the control device]
The control unit CU is composed of one or more control computers. For example, controller 100 has circuit 120 shown in FIG. Circuitry 120 includes one or more processors 121 , memory 122 , storage 123 and input/output ports 124 . The storage 123 has 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 procedure, which will be described later. The storage medium may be a removable medium such as a non-volatile semiconductor memory, a magnetic disk and an optical disk. The memory 122 temporarily stores the program loaded from the storage medium of the storage 123 and the calculation result by the processor 121 . The processor 121 cooperates with the memory 122 to execute the programs, thereby configuring each functional module described above. The input/output port 124 inputs/outputs electric signals to/from a member to be controlled according to a command from the processor 121 .

Note that the hardware configuration of the control unit CU is not necessarily limited to configuring each functional module by a program. For example, each functional module of the control device 100 may be composed of a dedicated logic circuit or an ASIC (Application Specific Integrated Circuit) integrated with this.

Further, the control unit CU has a storage unit CU1 and a control unit CU2, as shown in FIG. The storage unit CU1 stores a program for operating each part of the coating/developing apparatus 1 and each part of the exposure apparatus E1. Although the details will be described later, the storage unit CU1 also stores various types of data (for example, foreign object size data and foreign object position data) and captured images captured by the imaging unit 26 . The storage unit CU1 is, for example, a semiconductor memory, an optical recording disk, a magnetic recording disk, or a magneto-optical recording disk. The program may also be included in an external storage device separate from the storage unit CU1, or an intangible medium such as a propagated signal. The program may be installed in the storage unit CU1 from these other media and stored in the storage unit CU1. The control unit CU2 controls the operation of each unit of the coating/developing apparatus 1 and each unit of the exposure apparatus E1 based on the program read from the storage unit CU1.

The control unit CU is connected to the display unit D, and may cause the display unit D to display a processing condition setting screen, the processing progress of the wafer W by the coating/developing apparatus 1, the processing result, and the like. The coating/developing apparatus 1 may further have an input section (not shown) through which the operator can input processing conditions. In this case, the control unit CU may operate each unit of the coating/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 input units include a mouse, touch panel, pen tablet, and keyboard.

[Operation of Coating/Developing Device]
Next, an overview of the operation of the coating/developing apparatus 1 will be described. First, carrier 11 is installed in carrier station 12 . At this time, one side surface 11 a of the carrier 11 faces the opening/closing door 13 a of the loading/unloading section 13 . Subsequently, both the opening/closing door of the carrier 11 and the opening/closing door 13a of the loading/unloading section 13 are opened, and the transfer arm A1 takes out the wafer W from the carrier 11 and sequentially transports it to one of the cells of the shelf unit U10 of the processing block S2.

After the wafer W is transferred by the delivery arm A1 to any cell of the shelf unit U10, the wafer W is transferred to the cell C33 corresponding to the BCT block 14 by the elevating arm A7. The wafer W transferred to the cell C33 is transferred to each unit in the BCT block 14 by the transfer arm A2. A lower anti-reflection film is formed on the surface Wa of the wafer W while the wafer W is being transferred within the BCT block 14 by the transfer arm A2.

Wafer W on which the lower antireflection film is formed is transferred to cell C34 above cell C33 by transfer arm A2. The wafer W transferred to the cell C34 is transferred to the cell C35 corresponding to the COT block 15 by the elevating arm A7. The wafer W transferred to the cell C35 is transferred to each unit in the COT block 15 by the transfer arm A3. A resist film is formed on the lower anti-reflection film while the wafer W is being transferred within the COT block 15 by the transfer arm A3.

The wafer W on which the resist film is formed is transferred to the cell C36 above the cell C35 by the transfer arm A3. The wafer W transferred to the cell C36 is transferred to the cell C37 corresponding to the TCT block 16 by the elevating arm A7. The wafer W transferred to the cell C37 is transferred to each unit in the TCT block 16 by the transfer arm A4. While the wafer W is transported within the TCT block 16 by the transport arm A4, an upper antireflection film is formed on the resist film.

Wafer W on which the upper antireflection film is formed is transferred to cell C38 above cell C37 by transfer arm A4. The wafer W transferred to the cell C38 is transferred to the cell C32 by the lifting arm A7, and then transferred to the cell C42 of the shelf unit U11 by the transfer arm A6. The wafer W transported to the cell C42 is transferred to the exposure apparatus E1 by the transfer arm A8 of the interface block S3, and exposure processing of the resist film is performed in the exposure apparatus E1. Wafers W that have undergone exposure processing are transferred to cells C40 and C41 below cell C42 by transfer arm A8.

The wafers W transported to the cells C40 and C41 are transported to each unit in the DEV block 17 by the transport arm A5, and developed. Thereby, a resist pattern (concavo-convex pattern) is formed on the surface Wa of the wafer W. As shown in FIG. The wafer W on which the resist pattern is formed is transferred to the cells C30 and C31 corresponding to the DEV block 17 in the shelf unit U10 by the transfer arm A5. The wafers W transferred to the cells C30 and C31 are transferred by the elevating arm A7 to a cell accessible by the transfer arm A1, and returned into the carrier 11 by the transfer arm A1.

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

[Development processing unit (substrate processing apparatus)]
Next, the development processing unit (substrate processing apparatus) U1 will be described in more detail. The development processing unit U1 sequentially executes a discharge process for discharging the processing liquid onto the front surface Wa of the wafer W for each of the plurality of wafers W one by one. The development processing unit U1 includes a rotation holding section 20, an elevating device 22, and a processing liquid supply section 24, as shown in FIG.

The rotary holding unit 20 has a main body 20a containing a power source such as an electric motor, a rotary shaft 20b extending vertically upward from the main body 20a, and a chuck 20c provided at the tip of the rotary shaft 20b. The body portion 20a rotates the rotating shaft 20b and the chuck 20c by a power source. The chuck 20c supports the central portion of the wafer W and holds the wafer W substantially horizontally, for example, by suction. That is, the rotation holding unit 20 rotates the wafer W about a central axis (vertical axis) perpendicular to the front surface Wa of the wafer W, with the attitude of the wafer W being substantially horizontal. As shown in FIG. 4, the rotation holding unit 20 rotates the wafer W clockwise, for example, when viewed from above.

The lifting device 22 is attached to the rotation holding part 20 and lifts the rotation holding part 20 up and down. Specifically, the lifting device 22 lifts and lowers the rotary holding unit 20 (chuck 20c) between a raised position (transfer position) for transferring the wafer W between the transfer arm A5 and the chuck 20c and a lowered position (developing position) for liquid processing.

A cup 30 is provided around the rotation holding portion 20 . When the wafer W rotates, the processing liquid supplied to the surface Wa of the wafer W is shaken off and dropped, and the cup 30 functions as a container for receiving the dropped processing liquid. The cup 30 has an annular bottom plate 31 that surrounds the rotation holding part 20, a cylindrical outer wall 32 that projects vertically upward from the outer edge of the bottom plate 31, and a cylindrical inner wall 33 that projects vertically upward from the inner edge of the bottom plate 31.

The entire outer wall 32 is located outside the wafer W held by the chuck 20c. The upper end 32a of the outer wall 32 is located above the wafer W held by the rotation holding part 20 in the lowered position. A portion of the outer wall 32 on the side of the upper end 32a forms an inclined wall portion 32b that is inclined inward as it goes upward. The entire inner wall 33 is located inside the peripheral edge of the wafer W held by the chuck 20c. An upper end 33a of the inner wall 33 is located below the wafer W held by the rotation holding part 20 in the lowered position.

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

An umbrella-shaped portion 37 is provided on the inner wall 33 to protrude outward from the partition wall 34 . The processing liquid that has been shaken off and dropped from the wafer W is guided between the outer wall 32 and the partition wall 34 and discharged from the liquid discharge hole 31a. A gas or the like generated from the processing liquid enters between the partition wall 34 and the inner wall 33 and is discharged from the gas discharge hole 31b.

The upper part of the space surrounded by the inner wall 33 is closed by a partition plate 38 . A body portion 20 a of the rotation holding portion 20 is positioned below the partition plate 38 . The chuck 20 c is positioned above the partition plate 38 . The rotary shaft 20b is inserted through a through hole formed in the center of the partition plate 38. As shown in FIG.

The processing liquid supply unit 24 includes a processing liquid supply source 24a, a head unit 24c, a moving body 24d, and an imaging unit 26, as shown in FIG. The supply source 24a has a processing liquid storage container, a pump, a valve, and the like. 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 portion 24c is connected to the supply source 24a via the supply pipe 24b. The head portion 24c is positioned above the surface Wa of the wafer W when the processing liquid is supplied. A liquid nozzle N provided in the head portion 24c opens downward toward the front surface Wa of the wafer W. As shown in FIG. Accordingly, the head unit 24c ejects the processing liquid supplied from the supply source 24a from the liquid nozzle N onto the surface Wa of the wafer W in response to the control signal from the control unit CU.

24 d of moving bodies are connected to the head part 24c via the arm 24e. The movable body 24d receives a control signal from the control unit CU and moves horizontally (eg, in the X-axis direction) on a guide rail (not shown). As a result, the head unit 24c moves horizontally along the radial direction of the wafer W above the wafer W in the lowered position and on a straight line perpendicular to the central axis of the wafer W in the ejection process of ejecting the processing liquid from the ejection port Na of the liquid nozzle N onto the surface Wa of the wafer W. The moving body 24d raises and lowers the arm 24e upon receiving a control signal from the control unit CU. As a result, the head portion 24c moves vertically and approaches or separates from the front surface Wa of the wafer W. As shown in FIG.

The imaging section 26 is provided near the tip of the head section 24c as shown in FIG. 4, and moves together with the head section 24c. The imaging unit 26 images the discharge port Na portion of the liquid nozzle N. As shown in FIG. A captured image captured by the imaging unit 26 is transmitted to the control unit CU2 of the control unit CU. The control unit CU2 performs image processing on the received captured image to obtain information regarding the presence or absence of deposits near the discharge port Na of the liquid nozzle N, the amount of deposits, and the like. Examples of the deposits in the present embodiment include droplets, solids (solidified/crystallized processing liquid, foreign matter), and the like. The control unit CU2 performs an abnormality determination regarding the liquid nozzle N based on the result of the adhering matter in the vicinity of the discharge port Na of the liquid nozzle N, and cleans the liquid nozzle N when there is an abnormality. In addition, if the abnormality persists, measures to be taken in the event of an abnormality (for example, issuing an alarm, notifying an abnormality, etc.) will be implemented.

The imaging unit 26 is configured to be capable of imaging the entire periphery of the vicinity of the discharge port Na of the liquid nozzle N. As shown in FIG. The vicinity of the ejection opening Na of the liquid nozzle N is a region where the processing liquid ejected from the ejection opening Na may adhere. The area to which the processing liquid adheres can be changed according to the ejection speed (discharge amount per unit time) of the processing liquid, the rotational speed of the wafer W, and the like. Therefore, the place where the processing liquid may adhere during normal operation can be treated as the vicinity of the discharge port Na. Specifically, for example, it is about 0.5 mm to several mm from the lower end of the ejection port Na.

When the processing liquid is ejected from the ejection port Na, if the processing liquid adheres to the lower end portion or the peripheral edge of the ejection port Na and remains there, when the processing liquid is subsequently ejected again, the deposits may flow toward the wafer W together with the processing liquid in the initial stage of ejection. When the amount of the processing liquid supplied to the wafer W is large, the processing liquid in the initial stage of ejection is discharged from the wafer W, so the deposits are also discharged from the wafer W. FIG. However, when the supply amount of the processing liquid is small, the processing liquid in the initial stage of ejection also remains on the wafer W, so that the adherents remain on the wafer W as well. In such a case, the adhering matter may become a foreign substance on the wafer W and affect the processing accuracy of the substrate. From the above point of view, the imaging unit 26 images the entire periphery of the liquid nozzle N in the vicinity of the ejection port Na. Note that the image capturing unit 26 may be capable of capturing an image of the adhering matter on the entire circumference near the ejection port Na. Therefore, the image acquired by the imaging unit 26 should include an image of the entire periphery at least in a part near the ejection port Na. In addition, the image obtained by capturing the entire periphery near the discharge port Na of the liquid nozzle N may not be captured simultaneously, and may be a combination of a plurality of images captured with a slight time difference. As described above, the deposits adhering to the vicinity of the ejection port Na are mainly derived from the processing liquid ejected from the liquid nozzle N, and the state thereof may change after a certain amount of time due to drying, moisture absorption, or the like. In the imaging unit 26, a plurality of images are captured with a time difference (for example, several seconds to several minutes) that does not cause the change in the state of the adhering matter, thereby obtaining an image of the entire circumference.

Although FIG. 4 schematically shows the imaging unit 26, the configuration of the imaging unit 26 for imaging the entire circumference is not particularly limited. 6 to 8 are diagrams illustrating configuration examples of the imaging unit 26. FIG.

FIG. 6A shows a configuration in which an imaging unit 26 is composed of a plurality of cameras 27 and captures an image of the entire periphery of the liquid nozzle N in the vicinity of the discharge port Na. Although FIG. 6A shows an example in which three cameras 27 are arranged, the number of imaging units 26 is not particularly limited. By arranging the plurality of imaging units 26 so as to be able to capture images of the entire periphery near the ejection opening Na from different directions, an image of the entire periphery near the ejection opening Na of the liquid nozzle N can be obtained. When arranging the three cameras 27, for example, the three cameras 27 can be evenly arranged in the circumferential direction so that, in plan view, a line connecting the adjacent camera 27 and the discharge port Na of the liquid nozzle N and a line connecting the own camera and the discharge port Na form an angle of 120°. Thereby, the three cameras 27 can be configured to uniformly image the entire periphery in the vicinity of the discharge port Na. Although the plurality of cameras 27 may be arranged on the same horizontal plane (XY plane), for example, they may be arranged at different height positions in the vertical direction (Z-axis direction). The camera 27 may be provided, for example, in the treatment liquid supply section 24 or may be attached to the outer wall 32 of the cup 30 or the like. That is, there is no particular limitation as to which position (member) the camera 27 is attached to in the developing processing unit U1.

FIG. 6B shows a state in which the imaging section 26 is configured with one camera 27 and one mirror 28 . In such a configuration, the camera 27 captures an image of the vicinity of the discharge port Na of the liquid nozzle N reflected on the mirror 28 . For example, the mirror 28 is arranged below the outlet Na (in the negative direction of the Z-axis) as shown in FIG. On the other hand, the camera 27 is arranged so as to face the reflecting surface of the mirror 28 . As a result, the camera 27 can capture an image of the vicinity of the ejection port Na reflected by the mirror 28 . In addition, by adopting the configuration using the mirror 28, it is possible to image the vicinity of the ejection port Na on the blind spot side from the camera 27, and an image of the entire periphery in the vicinity of the ejection port Na of the liquid nozzle N can be obtained. Note that the arrangement of the camera 27 and the mirror 28 can be changed as appropriate.

FIG. 6(c) shows a state in which the imaging section 26 is configured by one camera 27. As shown in FIG. The camera 27 is arranged directly below the discharge port Na of the liquid nozzle N (Z-axis negative direction). With such a configuration, the camera 27 can image the entire periphery of the lower end of the discharge port Na of the liquid nozzle N at once. That is, even in the case of the configuration shown in FIG. 6C, it is possible to image the entire periphery in the vicinity of the ejection port Na. In addition, in the case where the liquid nozzle N shown in FIG. 6 and the like has a shape in which the tip tapers toward the ejection port Na, it can be said that the camera 27 shown in FIG. Alternatively, as shown in FIG. 6C, the camera 27 may be arranged directly below the ejection port Na, and a mirror 28 may be used to allow the camera 27 to capture an image of the side surface of the liquid nozzle N in the vicinity of the ejection port Na.

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 portion 24c and the mirror 28 is arranged below the liquid nozzle N. FIG. The height position of the arm 24e is not limited to the configuration shown in FIG. 4, and can be changed as appropriate by changing the configuration of other members such as changing the configuration of the head portion 24c. Further, instead of the mirror 28, a substrate (bare wafer) with a flat surface held by the chuck 20c may be used. In this case, the camera 27 captures an image of the vicinity of the discharge port Na of the liquid nozzle N reflected on the bare wafer.

8 shows another example of the arrangement of the camera 27 and the mirror 28, in which the camera 27 is attached to the arm 24e connected to the head part 24c and the mirror 28 is arranged around the liquid nozzle N. FIG. FIG. 8(a) is a side view of the above configuration, and FIG. 8(b) is a view schematically showing the positional relationship among the liquid nozzle N, the camera 27 and the mirror 28 when viewed from above. The example shown in FIG. 8 has the same mounting position of the camera 27 as the example shown in FIG. 7, but the arrangement of the mirror 28 is different. Specifically, the mirror 28 is arranged so that the outer wall of the side surface of the liquid nozzle N, which is a blind spot with respect to the camera 27, is reflected on the mirror 28. As shown in FIG. 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 reflected on the mirror 28 . With such a configuration, the camera 27 can capture an image of the entire circumference of the side surface of the liquid nozzle N in one image capturing.

As described above, the configuration of the imaging unit 26 is not particularly limited, and various configurations can be applied. The configuration examples shown above may be combined. Also, a camera 27 having a moving mechanism capable of changing the position of the liquid nozzle N may be used as the imaging section 26 . When the camera 27 is arranged near the ejection port 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.

[Nozzle inspection method]
Next, referring to FIGS. 9 to 16, a procedure for inspecting the ejection port Na of the liquid nozzle N in the development processing unit U1 will be described. FIG. 9 is a flowchart for explaining a series of procedures related to the inspection method. 10 and 13 are flow charts for explaining the procedure for image processing and adhesion state evaluation, and FIGS.

First, the control unit CU2 of the control unit CU executes step S01. In step S01, a reference image for evaluating the state of deposits in the vicinity of the discharge port Na of the liquid nozzle N is obtained. This reference image is an image of the vicinity of the ejection port Na of the liquid nozzle N in a state where no deposit is attached, and corresponds to the image of the entire periphery of the vicinity of the ejection port Na of the liquid nozzle N acquired during inspection. The control unit CU2 controls the imaging unit 26 to obtain a reference image of the vicinity of the discharge port Na of the liquid nozzle N. FIG. The acquired reference image may be configured to be stored in the storage unit CU1.

Next, control unit CU2 executes step S02. In step S02, the control unit CU2 acquires an inspection image related to the entire periphery near the discharge port Na of the liquid nozzle N (image acquisition control). An inspection image is an image to be subjected to an evaluation or the like relating to adhering matter. The control unit CU2 controls the imaging unit 26 to obtain an inspection image of the vicinity of the discharge port Na of the liquid nozzle N. FIG. The timing of executing step S02 may be a preset timing (for example, after the processing of wafers W in lot units is completed). Further, the step S02 may be executed based on the evaluation result of the wafer W or the like after processing in the developing processing unit U1. In the case where a plurality of images are combined to obtain an image of the entire periphery near the ejection port Na of the liquid nozzle N, a configuration may be adopted in which a series of the plurality of images are treated as one inspection image. The acquired inspection image may be configured to be stored in the storage unit CU1.

Next, control unit CU2 executes step S03. In step S03, the control unit CU2 uses the reference image acquired in step S01 and the inspection image acquired in step S02 to perform image processing related to the evaluation of adhering matter (evaluation control). Next, control unit CU2 executes step S04. In step S04, based on the image that has been processed in step S03, the state of adherence of the adhering matter is evaluated (evaluation control). The above steps S03 and S04 will be described later.

Next, control unit CU2 executes step S05. In step S05, as a result of the adhesion state evaluation in step S04, it is determined whether or not there is an abnormality in the liquid nozzle N (determination control). Determining whether or not there is an abnormality at this stage means determining whether or not the wafer W can be processed using the liquid nozzle N as it is. Therefore, if it is determined that there is no abnormality, it is determined that there is no operation to be performed for the liquid nozzle N based on the inspection result of the liquid nozzle N, and the series of processes is terminated.

When it is determined that there is an abnormality in step S05, control unit CU2 executes step S06. In step S06, if it is determined that there is an abnormality in this determination, it is determined whether it is necessary to perform an operation to be performed on the liquid nozzle N, such as a forced stop (abnormal stop) based on the abnormality of the apparatus (determination control). If it is determined that there is an abnormality, it will be the case that it is detected that there is an adhering substance in the vicinity of the discharge port Na of the liquid nozzle N. In such a case, the vicinity of the discharge port Na of the normal liquid nozzle N is washed. However, if it is necessary to take some action other than cleaning the nozzles, such as when it is determined that there is a repeated abnormality, for example, it is determined that an abnormal stop is necessary. In this case, control unit CU2 executes step S07. That is, in step S07, the control unit CU2 forcibly stops the substrate processing in the development processing unit U1. In addition, although FIG. 8 describes the case of judging whether or not an abnormal stop is necessary and performing an abnormal stop, it is also possible to adopt a configuration in which only an alarm notification is performed instead of an abnormal stop. Further, in step S06, it may be configured to determine which of abnormal stop and warning notification is to be performed.

If it is determined in step S06 that the abnormal stop is not necessary, the 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 development processing unit U1 and performs processing related to cleaning the liquid nozzle N. FIG. It should be noted that the cleaning method of the liquid nozzle N in step S08 may be changed based on the evaluation result of the adhesion state. This point will be described later.

[Specific procedure from image processing to abnormality determination]
Next, specific procedures for determining whether there is an abnormality in the vicinity of the discharge port Na of the liquid nozzle N will be described with reference to FIGS. 10 to 12. FIG. The procedure described here is one of the specific procedures of steps S03 to S06 in FIG.

First, the control unit CU2 executes step S11. In step S11, the control unit CU2 calculates a difference between the reference image and the inspection image held in the storage unit CU1. By calculating the difference, it is possible to grasp how much each pixel in the inspection image changes from the reference image from the luminance value. Changes in the inspection image with respect to the reference image, ie, portions where the brightness value is different from 0, are considered to be affected by adhesion of deposits. That is, by performing processing for creating an image related to the difference, it is possible to estimate the area of the adhering matter.

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

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

A specific example will be described with reference to FIG. FIG. 11 shows an example of an image of the vicinity of the discharge port Na of the liquid nozzle N captured obliquely downward. In FIG. 11, an image with a total of 307,200 pixels of 480 vertical pixels×640 horizontal pixels is used. FIG. 11A corresponds to a reference image in the vicinity of the ejection port Na of the liquid nozzle N. FIG. On the other hand, FIG. 11(b) is an image corresponding to the inspection image, and is an image showing a state in which there is almost no adhering matter. FIG. 11(c) shows the result of calculating the difference between these two images. The image shown in FIG. 11C is a monochrome image in which the difference in luminance value (pixel value) of each pixel of the two images is shown at the position corresponding to each pixel. If the reference image and the inspection image are color images, the difference between the luminance values may be calculated after each of them is grayscaled. In the case of a color image, FIG. 11(c) shows the luminance value (0 to 255) of each pixel as a gray scale, and the higher the luminance value, the whiter the image. For reference, FIG. 11(c) shows a state in which the brightness of the entire image has been adjusted. Note that when the reference image and the inspection image are color images, a method of calculating the pixel value of each pixel by a method different from grayscaling may be used.

As in the inspection image shown in FIG. 11(b), if the inspection image is an image obtained by imaging a state in which there is almost no adhering matter, as shown in FIG. In the example shown in FIG. 11C, the average luminance value is 2.95. On the other hand, FIG. 11D is an image corresponding to a different inspection image from FIG. When the difference between these two images is calculated, as shown in FIG. 11(e), there are pixels having a certain luminance value (appearing white) in the area where the deposit is thought to be attached. In this case, the average value of luminance values increases. In the example shown in FIG. 11E, the average luminance value is 2.95. In this way, the average value of the luminance values of the difference image using the reference image changes depending on the adherence state of the adhering matter. Therefore, when this average value is larger than a predetermined threshold value, it can be determined that there is an abnormality by determining that there is an adhering substance in the vicinity of the discharge port Na of the liquid nozzle N. For reference, FIG. 11E shows a state in which the brightness of the entire image is adjusted.

A specific example different from FIG. 11 will be described with reference to FIG. FIG. 12 shows an example of an image of the vicinity of the ejection port Na of the liquid nozzle N captured from directly below the ejection port Na. In FIG. 12, an image with a total of 307,200 pixels of 640 vertical pixels×480 horizontal pixels is used. FIG. 12A corresponds to a reference image in the vicinity of the ejection port Na of the liquid nozzle N. FIG. On the other hand, FIG. 12B is an image showing a state in which deposits are present near the tip of the ejection port Na of the liquid nozzle N. FIG. FIG. 12(c) shows the result of calculating the difference between these two images. FIG. 12(c) is an image showing the result of calculating the luminance value of the difference using the same method as in FIGS. 11(c) and 11(e). FIG. 12(c) also shows a state in which the brightness of the entire image has been adjusted. As shown in FIG. 12(c), pixels having a certain luminance value (appearing white) are present in the area where the deposit is thought to be attached. In this case as well, the average value of the luminance values of all pixels is expected to be somewhat large. Therefore, when the average value is larger than a predetermined threshold value, it is possible to determine that there is an abnormality by determining that there is an adhering substance in the vicinity of the discharge port Na of the liquid nozzle N.

In addition, in the difference image shown in FIG. 12C, the images of the deposits adhering to the inner wall side and the outer wall side of the ejection port Na of the liquid nozzle N can be distinguished. That is, in the area corresponding to the end surface of the lower end of the ejection port Na, both the reference image and the inspection image have approximately the same brightness, so the brightness of the difference image is 0 or close to 0. On the other hand, inside the inner wall surface and outside the outer wall surface, as shown in FIG. Therefore, as shown in FIG. 12(c), regions with large luminance values can be seen in each region in the differential image as well.

In the case of the example shown in FIG. 12, deposits on the inner wall and deposits on the outer wall can be distinguished as described above. Therefore, when evaluating deposits near the discharge port Na of the liquid nozzle N using such an image, the evaluation can be performed by distinguishing between deposits on the inner wall side and deposits on the outer wall side. Further, as in the example shown in FIG. 12, when the resolution of the image obtained by capturing the vicinity of the discharge port Na of the liquid nozzle N is high, the characteristics of the adhering substances are reflected in the image. Therefore, it is possible to obtain information about the properties of the adhering matter from the inspection image or the differential image and specify the type of the adhering matter.

Therefore, with reference to FIGS. 13 to 16, a specific procedure for determining the presence or absence of an abnormality in the vicinity of the discharge port Na of the liquid nozzle N based on the evaluation of the adhesion position of the adhering matter and the evaluation of the type of the adhering matter will be described. The procedure described here is one of the specific procedures of steps S03 to S06 in FIG.

14 to 16 show specific examples using an image of the lower end of the discharge port Na of the liquid nozzle N as in FIG. However, the same procedure can be performed even when an image of the discharge port Na of the liquid nozzle N described in FIG. 11 is captured obliquely from below as the inspection image. The same procedure can be performed even when an image obtained by imaging the entire circumference of the side surface of the liquid nozzle N in the vicinity of the discharge port Na is used as the 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. For example, depending on the orientation of the liquid nozzle N in the inspection image, the location subject to abnormality determination (side surface, bottom end, etc. of the liquid nozzle N) may change.

First, the control unit CU2 executes step S21. At step S21, the control unit CU2 calculates a difference between the reference image and the inspection image held in the storage unit CU1. This procedure is similar to step S11.

Next, the control unit CU2 executes step S22. In step S22, the control unit CU2 estimates the adhering position of the adhering matter in the vicinity of the ejection port Na of the liquid nozzle N based on the nozzle shape information in the vicinity of the ejection port Na of the liquid nozzle N. FIG. The nozzle shape information specifies the shape of the liquid nozzle N. FIG. In this embodiment, the outer shape of the lower end of the liquid nozzle N, that is, the contour of the lower end, is the nozzle shape information. That is, the nozzle shape information is information that can specify the shape of the nozzle in a state where no deposit is attached.
As shown in FIG. 12C, the contour of the lower end of the ejection port Na of the liquid nozzle N can be specified in the difference image between the reference image and the inspection image. That is, as shown in FIG. 14A, the outline of the lower end of the ejection 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. Note that the nozzle shape information may be stored in advance in the storage unit CU1 of the control unit CU instead of being acquired from the difference image. The imaging position of the image near the discharge port Na of the liquid nozzle N captured by the imaging unit 26 is basically determined as described above. Therefore, the position of the lower end of the ejection port Na of the liquid nozzle N in the inspection image is basically unchanged, and the nozzle shape information of the ejection port Na of the liquid nozzle N included in the inspection image can be held in advance.

By using the nozzle shape information as described above, it is possible to estimate whether the area where the attached matter, which is the area with the high luminance value in the difference image, is on the inner wall side or the outer wall side of the liquid nozzle N. That is, it is possible to estimate the adhesion position of the deposit using the nozzle shape information included in the difference image. In the present embodiment, the estimation of the adhering position of the adhering matter at this stage is explained as to whether the adhering position is on the inner wall side or the outer wall side. However, as a more detailed adhesion position, for example, it is possible to estimate in which direction the adhered matter is located with respect to the center of the liquid nozzle N, how far the distance from the discharge port Na of the liquid nozzle N is, and the like. Depending on which direction the inspection image was taken, the adhesion position (positional relationship in the vertical direction, radial direction, etc.) that can be estimated from the image may change.

Next, the control unit CU2 executes step S23. In step S23, the control unit CU2 evaluates the adhered amount of adhered matter from the number of pixels in which the adhered matter is imaged for each adhered position. FIG. 14(b) shows an example of extracting only the region where the image of the image shown in FIG. 12(c) was binarized based on a predetermined threshold value, and then the image of the adhering matter on the outer wall side was taken. Also, FIG. 14(c) shows an example of extracting only a region where the image of the image shown in FIG. 12(c) was binarized based on a predetermined threshold value, and then an image of the attached matter on the inner wall side was taken. In this way, after the binarization process is performed, the number of pixels (the number of pixels) in which the deposits on the outer wall side/inner wall side of the liquid nozzle N are captured can be calculated by extracting the imaged area of the deposits on the outer wall side/inner wall side. For example, in the example shown in FIG. 14B, 12649 pixels can be counted as the number of pixels that captured the attached matter on the outer wall side. Also, in the example shown in FIG. 14C, the number of pixels that captured the attached matter on the inner wall side can be counted as 5426 pixels. In this way, the amount of adhering matter can be evaluated from the number of pixels in which the adhering matter is imaged, that is, the area in which the adhering matter is imaged. The adhesion amount calculated in this manner can be used as information for determining the presence or absence of an abnormality.

Next, the control unit CU2 executes step S24. At step S24, the control unit CU2 evaluates the type of adhering matter. As described above, the types of deposits can be broadly classified into liquids (droplets) and solids (solids). At step S24, the control unit CU2 distinguishes between these two types based on the inspection image or the difference image.

An example of the procedure for identifying the type of adhering matter will be described with reference to FIG. FIG. 15(a) is an inspection image obtained by imaging a state in which liquid droplets adhere to the outer wall side near the discharge port Na of the liquid nozzle N. FIG. FIG. 15(b) is an image obtained by performing binarization processing on the inspection image shown in FIG. 15(a) based on a predetermined threshold value. On the other hand, FIG. 15(c) is an inspection image obtained by imaging a state in which a solid substance adheres to the outer wall side near the discharge port Na of the liquid nozzle N. FIG. FIG. 15(d) is an image obtained by binarizing the inspection image shown in FIG. 15(c) based on a predetermined threshold value.

As can be seen from the comparison between FIG. 15(a) and FIG. 15(c), the appearance of the picked-up image changes depending on whether the droplet adheres or the solid substance adheres. Specifically, when a liquid droplet adheres, the external shape of the adhering substance becomes smooth and the way it shines is uniform, so that the image also has a smooth shape. On the other hand, when a solid substance adheres, fine unevenness may remain on the outer shape of the adhered substance (the shape may naturally differ depending on the solid substance), so that the lighting becomes sparse and the unevenness remains clearly on the image. The above difference can also be grasped in the binarized images shown in FIGS. 15(b) and 15(d). Therefore, it is also possible to determine whether the adhering matter is liquid or solid by estimating the outer shape (unevenness) of the adhering matter using the binarized image obtained by evaluating the adhering amount. It should be noted that the type of adhering matter may be determined directly from the inspection image (images shown in FIGS. 15A and 15C) instead of the binarized image. Further, when estimating the outer shape (unevenness), polar coordinate expansion may be performed.

Further, instead of determining based on the unevenness of the outer shape of the attached matter as described above, for example, determination may be performed based on the size (the number of pixels) of an imaged area of one attached matter. For example, since a droplet does not exist by itself unless it reaches a certain size, it can be estimated that the image of the droplet will have a larger area in which the adhering matter is imaged. On the other hand, a solid substance can exist alone even if it is smaller than a droplet. Based on this, based on the size (the number of pixels) of a continuous area estimated to capture one attached object, it may be determined that a liquid droplet exists in an area larger than a predetermined threshold, and that a solid substance exists in other areas. In this way, the method of determining the type of deposits 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, the image after binarization) is not particularly limited, and various methods can be applied.

Next, the control unit CU2 executes step S25. At step S25, the control unit CU2 determines the presence or absence of an abnormality from the various information obtained at steps S23 and S24. For example, by executing step S23, the control unit CU2 can obtain information about the amount of adhered matter. Further, by executing step S24, the control unit CU2 can obtain information about the type of the adhering matter. These pieces of information can be used to determine the presence or absence of an abnormality.

The reference for determining the presence or absence of abnormality from the amount of adhering matter may simply be the number of pixels in which the adhering matter is imaged, but is not limited to this configuration. For example, the presence or absence of abnormality may be determined based on the magnitude of the luminance value (pixel value) of the pixel that captured the attached matter. In addition, it is also possible to adopt a configuration in which the manner in which the adhered matter adheres is included in the criteria for determining the presence or absence of an abnormality. FIG. 16 is a diagram illustrating an example of a case where the "state" of adhering matter is also taken into consideration. In FIG. 16, two reference lines L1 and L2 for determining the presence or absence of abnormality are added to the image obtained by extracting the area of the attached matter on the outer wall shown in FIG. 14(b). The reference lines L1 and L2 are circles whose distances from the outer wall are different from each other while the center of the discharge port Na of the liquid nozzle N is used as a reference. That is, the reference line L1 is a line indicating 100 μm outside the outer wall, and the reference line L2 is a line indicating 50 μm outside the outer wall. The reference lines L1 and L2 are provided in advance, and the presence or absence of an abnormality can be determined from the positional relationship between the reference lines L1 and L2 and the pixels that captured the attached matter. For example, it may be determined that an abnormal stop is necessary when the adhering matter protrudes outside the reference line L1. Alternatively, if the adhering matter does not protrude outside the reference line L1 but protrudes outside the reference line L2, it may be determined that there is an abnormality and issue a warning. It is also possible to adopt an aspect in which it is determined that there is an abnormality when the number of pixels in the imaged area of the attached matter protruding outside the reference line L1 or the reference line L2 exceeds a predetermined amount. In this manner, the reference lines L1 and L2 may be used as references for determining whether or not there is an abnormality.

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

FIG. 17 shows an example of the 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 the inner wall near the discharge port Na of the liquid nozzle N is dirty (whether or not there is an adhering matter) based on the result of specifying the position of the adhering matter (step S22). As a result, when it is determined that there is an adhering matter on the inner wall side, the control unit CU2 executes step S32. That is, the control unit CU2 cleans the liquid nozzle N by a method that enables the inner wall of the liquid nozzle N to be cleaned in step S32. In this case, it is possible to adopt a mode in which the cleaning of the inside of the liquid nozzle N and the cleaning of the outer wall are performed. On the other hand, when it is determined that there is no deposit on the inner wall side of the step, the control unit CU2 executes step S33. That is, the control unit CU2 cleans the nozzle tip. Cleaning of the nozzle tip is a method of mainly cleaning the outer wall of the nozzle, and is a method with fewer steps than cleaning of the inner wall. In this manner, the cleaning method may be changed according to the position of the adhering matter. Alternatively, a predetermined cleaning method may be executed when cleaning is required without selecting the cleaning method according to the adhesion position of the adhering matter (step S26).

In the above embodiment, two procedures have been described with reference to FIGS. 10 and 13. FIG. However, regarding the determination of the presence or absence of an abnormality in the liquid nozzle N in particular, the control unit CU2 may perform both of the procedures described with reference to FIGS. 10 and 13 at the same time, or may perform only one of them.

[Action]
According to the developing processing unit (substrate processing apparatus) U1 and the nozzle inspection method described above, the state of adhesion of matter adhering to the ejection port Na of the liquid nozzle N is evaluated based on the inspection image obtained by imaging the entire circumference of the vicinity of the ejection port Na of the liquid nozzle N. Further, more specifically, the imaged area of the adhering matter adhering to the liquid nozzle N is estimated, and the presence or absence of abnormality is determined based on the result. In this way, the evaluation is performed based on the image of the entire circumference of the vicinity of the discharge port Na of the liquid nozzle N, and as one aspect of the evaluation, the presence or absence of an abnormality is determined. Therefore, it is possible to reduce the possibility that the liquid nozzle N operates in a state where the deposit is attached, so that the adhesion state of the deposit near the discharge port Na of the nozzle can be evaluated more appropriately.

Conventionally, it has been considered to use an image when evaluating the state of a liquid nozzle that supplies a processing liquid in a substrate processing apparatus. However, when the configuration is such that evaluation is performed using an image of the liquid nozzle captured from one direction, if the deposit adheres to a location that cannot be captured by the image, the adherence may not be noticed. In such a case, there is a possibility that the abnormality determination of the liquid nozzle is erroneously determined. However, as described above, conventionally, a large amount of the processing liquid is supplied to the substrate, so there is a low possibility that deposits falling on the substrate surface together with the processing liquid in the initial stage of ejection pose a problem in substrate processing. Therefore, even with the above configuration, there was little possibility of causing a serious problem.

On the other hand, in the control of reducing the amount of processing liquid supplied to the substrate compared to conventional liquid processing, which has been studied in recent years, adhering matter mixed with the processing liquid in the initial stage of ejection may cause defects in the liquid processing on the substrate. Therefore, there has been a demand for a configuration for detecting adherence of substances to nozzles with higher accuracy. According to the above-described substrate processing apparatus and nozzle inspection method, it is possible to evaluate adhesion of deposits to nozzles with higher accuracy than in the conventional configuration, and to determine the presence or absence of an abnormality. Therefore, it is possible to cope with control of 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 take appropriate measures according to the evaluation result, and to take appropriate measures in consideration of the abnormality of the liquid nozzle N.

Further, as described in the above embodiment, the adhered state of the adhering matter is evaluated based on the pixel value or the number of pixels of the area where the adhering matter is imaged in the inspection image, and the presence or absence of an abnormality in the liquid nozzle N is determined based on the result. By adopting such a mode, the presence or absence of abnormality can be evaluated according to the adhered state of the adhering matter. Therefore, by adopting such a configuration, it is possible to more appropriately evaluate the adherence state of the adhering matter.

Further, in the above-described embodiment, it is estimated whether the adhering matter adhering to the liquid nozzle N estimated from the inspection image is liquid or solid. By adopting such a configuration, it is possible to evaluate how firmly the deposits are adhered in the vicinity of the discharge port Na of the liquid nozzle N, and to evaluate the adhesion state more appropriately.

In addition, in the above embodiment, by estimating the adhesion position of the adhering matter based on the inspection image, it is possible to more accurately evaluate how much the adhering matter affects the processing using the liquid nozzle N. In particular, depending on whether the deposit is attached to the inner wall side or the outer wall side of the liquid nozzle N, the risk of the deposit being discharged together with the processing liquid may change. Therefore, by having a configuration for estimating on which of the inner wall side and the outer wall side of the liquid nozzle N the adhering matter is attached, the influence of the adhering matter on the substrate processing can be evaluated more appropriately.

Further, in the above-described embodiment, the cleaning method for the liquid nozzle N is selected based on the evaluation result of the evaluation control. By adopting such a configuration, it is possible to perform appropriate cleaning according to the adhesion state of the adhering substances. Therefore, it is possible to remove the adhering portion from the liquid nozzle N favorably.

While various exemplary embodiments have been described above, various omissions, substitutions, and modifications may be made without being limited to the exemplary embodiments described above. Also, elements from different embodiments can be combined to form other embodiments.

For example, in the above embodiment, the control unit CU2 of the control unit CU controls the nozzle inspection. However, the functional units that perform nozzle test-related control may be concentrated in one device, or may be dispersedly arranged in a plurality of devices.

Also, the shapes of the liquid nozzle N and its discharge port Na can be changed as appropriate. The configuration of the imaging unit 26 can be changed depending on the shape of the ejection port Na. Also, the image used as the inspection image can be changed according to the shape of the liquid nozzle N. FIG.

Further, the method of estimating the area where the attached matter is imaged from the inspection image is not limited to the above embodiment. For example, in the above-described embodiment, regarding an image captured from directly below the ejection port Na of the liquid nozzle N, the evaluation of the deposits on the lower end (lower surface) of the ejection port Na is not described. On the other hand, for example, it is also possible to adopt a configuration in which deposits on the lower edge are also evaluated based on the distribution of luminance values of each pixel in the inspection image. Further, in the above-described embodiment, a case has been described in which an abnormality is determined based on a difference image generated using a reference image, but a configuration that does not use a difference image is also possible. Also, the configuration may be such that the reference image is not used either.

From the foregoing description, it will be appreciated that various embodiments of the present disclosure have been set forth herein for purposes of illustration, and that various changes may be made without departing from the scope and spirit of the present disclosure. Therefore, the various embodiments disclosed herein are not intended to be limiting, with a true scope and spirit being indicated by the following claims.

Reference Signs List 1 Coating/developing device 26 Imaging unit 27 Camera 28 Mirror CU Control device CU1 Storage unit CU2 Control unit D Display unit N Liquid nozzle Na Discharge port U1 Development processing unit (substrate processing apparatus) W Wafer (substrate) Wa Surface.

Claims (12)

a liquid nozzle for ejecting the processing liquid from the ejection port to the substrate below;
an imaging unit that captures an image of the entire periphery of the liquid nozzle in the vicinity of the ejection port;
a control unit;
The control unit
image acquisition control for acquiring an inspection image of the entire circumference related to the vicinity of the discharge port of the liquid nozzle imaged by the imaging unit;
evaluation control for evaluating a state of adherence of matter adhering to the ejection port of the liquid nozzle from an inspection image of the entire circumference related to the vicinity of the ejection port of the liquid nozzle;
executing determination control for determining an operation to be performed on the liquid nozzle based on the evaluation result of the evaluation control ;
In the image acquisition control, calculating a difference image between the inspection image and a reference image, which is an image of the entire circumference of the vicinity of the ejection port in a state where the adhering matter is not adhered;
In the evaluation control, calculating an average value of luminance values in the difference image;
In the determination control, the substrate processing apparatus determines an operation to be performed on the liquid nozzle based on whether the average value is equal to or greater than a threshold. The control unit
In the evaluation control, based on nozzle shape information specifying the shape of the nozzle and luminance values in the difference image, estimating a region where the deposit adheres to the nozzle,
2. The substrate processing apparatus according to claim 1, wherein, in said determination control, an operation to be performed with respect to said liquid nozzle is determined further based on a result of estimating an area to which said adhering matter adheres. 3. The substrate processing apparatus according to claim 2, wherein in the evaluation control, the control unit uses the nozzle shape information to estimate whether or not the area where the deposit adheres includes an area on the inner wall side of the liquid nozzle, and whether or not the area where the deposit adheres includes an area on the outer wall side of the liquid nozzle. 4. The substrate processing apparatus according to claim 3, wherein the control unit selects a cleaning method for the liquid nozzle as an operation to be executed for the liquid nozzle based on an estimation result of whether the area to which the deposit is attached includes an area on the inner wall side of the liquid nozzle and an estimation result of whether the area to which the deposit is attached includes an area on the outer wall side of the liquid nozzle. 3. The substrate processing apparatus according to claim 2, wherein in the evaluation control, the control unit performs binarization processing on the difference image, and estimates an area where the deposit adheres on the basis of the binarization processing on the difference image. The control unit
in the evaluation control, based on the outer shape or size of the imaged area of the adherent adhered to the liquid nozzle estimated from the inspection image, estimating whether the adherent adhered to the liquid nozzle is liquid or solid;
6. The substrate processing apparatus according to claim 1, wherein, in said determination control, an operation to be performed on said liquid nozzle is determined further based on a result of estimating whether said adhering matter is liquid or solid. The imaging unit has a plurality of cameras,
7. The substrate processing apparatus according to claim 1, wherein said plurality of cameras are evenly arranged in the circumferential direction in the vicinity of said ejection port of said nozzle. The imaging unit has a camera and a mirror,
The mirror is arranged below the outlet of the nozzle,
7. The substrate processing apparatus according to claim 1, wherein said camera is arranged so as to face the reflecting surface of said mirror. further comprising a support portion disposed below the ejection port of the nozzle for supporting the substrate;
The imaging unit has a camera,
7. The substrate processing apparatus according to claim 1, wherein said camera is arranged so as to face the surface of said substrate supported by said support portion on the side of said ejection port. The imaging unit has a camera, a mirror, and an arm extending in a direction perpendicular to a direction in which the ejection port and the substrate face each other,
the camera is connected to one end of the arm;
the nozzle is connected to the other end of the arm;
7. The substrate processing apparatus according to claim 1, wherein said mirror is arranged so as to reflect an outer wall on a side surface of said nozzle, which is a blind spot with respect to said camera. 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, comprising:
Acquiring an inspection image obtained by imaging the entire periphery of the liquid nozzle in the vicinity of the ejection port;
Evaluating a state of adherence of matter adhering to the ejection port of the liquid nozzle from an inspection image of the entire periphery in the vicinity of the ejection port of the liquid nozzle,
determining an operation to be performed on the liquid nozzle based on the evaluation result of the adhesion state;
In obtaining the inspection image, calculating a difference image between the inspection image and a reference image that is an image of the entire periphery of the vicinity of the ejection port in a state where the deposit is not adhered;
In evaluating the adhesion state, calculating the average value of the luminance values in the difference image,
A nozzle inspection method, wherein, in determining the operation to be performed on the liquid nozzle, the operation to be performed on the liquid nozzle is determined based on whether or not the average value is equal to or greater than a threshold value. A computer-readable storage medium storing a program for causing an apparatus to execute the nozzle inspection method according to claim 11 .

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