Foreign object detection device and foreign object detection method

Abstract

Provided is a device for detecting foreign matter which is configured to detect foreign matter contained in a processing liquid for substrate processing, said device comprising: a processing liquid flow path formation part that forms processing liquid flow paths through which flows the processing liquid supplied to a substrate; an irradiation unit that emits irradiation light from a light source toward the processing liquid flow paths; and a light receiving unit that receives the light emitted from the processing liquid flow path due to the irradiation with the irradiation light. The irradiation unit includes a light adjustment unit that varies the quantity of irradiation light which irradiates the plurality of processing liquid flow paths.

Description

[Technical Field]

[0001] The present disclosure relates to a foreign object detection device and a foreign object detection method. [Background technology]

[0002] Patent Document 1 discloses a substrate processing apparatus that optically detects foreign matter in a supply path through which a fluid supplied to a substrate flows, by projecting light onto a flow path forming section through which the fluid flows, receiving the light generated from the flow path forming section as a result, and detecting foreign matter from the intensity of the light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-119996 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that enables efficient foreign matter detection depending on the state of the target liquid. [Means for solving the problem]

[0005] A foreign matter detection device according to one aspect of the present disclosure is a foreign matter detection device configured to detect foreign matter contained in a processing liquid for substrate processing, and includes: a plurality of processing liquid flow path forming sections that form processing liquid flow paths through which the processing liquid supplied to the substrate flows; an irradiation section configured to be able to individually irradiate each of the plurality of processing liquid flow paths with irradiation light from a light source; and a light receiving section configured to receive light emitted from the processing liquid flow path by irradiation with the irradiation light, and the irradiation section includes a light adjustment section that varies the light intensity of the irradiation light that irradiates the plurality of processing liquid flow paths. [Effects of the Invention]

[0006] According to the present disclosure, a technique is provided that enables efficient foreign matter detection depending on the state of the target liquid. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic perspective view showing an example of a substrate processing system. [Figure 2] FIG. 2 is a schematic diagram showing an example of a coating and developing apparatus. [Figure 3] FIG. 3 is a schematic diagram showing an example of the liquid processing unit. [Figure 4] FIG. 4 is a schematic diagram illustrating an example of a processing liquid supply section of the liquid processing unit. [Figure 5] FIG. 5 is a side view schematically illustrating an example of a foreign object detection unit. [Figure 6] FIG. 6 is a perspective view schematically illustrating an example of a foreign object detection unit. [Figure 7] FIG. 7 is a side view schematically showing an example of a foreign object detection unit. [Figure 8] FIG. 8 is a block diagram showing an example of the functional configuration of the control unit. [Figure 9] FIG. 9 is a graph showing an example of signal intensity according to detected light. [Figure 10] 10(a) and 10(b) are diagrams illustrating an example of the relationship between the change in light intensity and the detected light. [Figure 11] FIG. 11 is a block diagram illustrating an example of a hardware configuration of the control unit. [Figure 12] FIG. 12 is a flowchart showing an example of a foreign object detection method. [Figure 13] FIG. 13 is a flowchart showing an example of a method for adjusting the intensity of light used in the foreign object detection method. [Figure 14] FIG. 14 is a side view schematically showing another example of the foreign object detection unit. DETAILED DESCRIPTION OF THE INVENTION

[0008] Various exemplary embodiments are described below.

[0009] In one exemplary embodiment, a foreign matter detection device is provided that is configured to detect foreign matter contained in a processing liquid for substrate processing, and includes: a processing liquid flow path forming unit that forms processing liquid flow paths through which the processing liquid flows to be supplied to a substrate; an irradiation unit that is configured to individually irradiate each of the plurality of processing liquid flow paths with irradiation light from a light source; and a light receiving unit that is configured to receive light emitted from the processing liquid flow paths by the irradiation of the irradiation light, wherein the irradiation unit includes a light adjustment unit that varies the light intensity of the irradiation light irradiating the plurality of processing liquid flow paths.

[0010] According to the foreign matter detection device, the light emitted from the light source is irradiated onto the treatment liquid flow path after its intensity is adjusted by a light adjusting unit included in the irradiation unit. In this case, if treatment liquids with different properties flow through the multiple treatment liquid flow paths or if the flow conditions, such as flow velocity and flow rate, are different, the intensity of the light irradiated onto the multiple treatment liquid flow paths can be adjusted, thereby enabling efficient foreign matter detection according to the state of the treatment liquid in each treatment liquid flow path. Furthermore, even if the target liquids in the multiple treatment liquid flow paths are the same in type or characteristics, the intensity of the light may be adjusted, for example, to set multiple foreign matter detection standards or to monitor the level of noise.

[0011] The irradiation unit may be configured to move relative to the plurality of treatment liquid flow paths to irradiate the irradiation light toward each of the plurality of treatment liquid flow paths, and the light adjustment unit may be provided on an optical path toward each of the plurality of treatment liquid flow paths. In this case, it is possible to individually adjust the light intensity for each treatment liquid flow path, thereby enabling flexible adjustment of the light intensity.

[0012] In one embodiment, the light adjusting unit adjusts the amount of the irradiation light irradiated onto one of the processing liquid flow paths so that the intensity of a haze noise component that varies depending on the intensity of the irradiation light approaches the intensity of a stationary noise component that occurs regardless of the intensity of the irradiation light, among noise components contained in the light received by the light receiving unit when the irradiation light is irradiated onto one of the processing liquid flow paths. Among the noise components contained in the light received by the light receiving unit, the haze noise component varies depending on the intensity of the irradiation light. Therefore, by adjusting the intensity of the irradiation light to approach the intensity of the stationary noise component, the intensity of the irradiation light can be adjusted to be reduced while preventing a decrease in the accuracy of foreign matter detection.

[0013] The apparatus may further include a control unit that acquires an electrical signal corresponding to the intensity of the light received by the light receiving unit, the control unit estimating the intensity of the stationary noise component and the intensity of the haze noise component based on the electrical signal corresponding to the light received by the light receiving unit when the irradiation light is irradiated onto the one processing liquid flow path, and the light adjusting unit adjusting the amount of the irradiation light irradiated onto the one processing liquid flow path based on the estimation result by the control unit so as to bring the intensity of the haze noise component, which varies depending on the intensity of the irradiation light, closer to the intensity of the stationary noise. With the above configuration, the intensity of the stationary noise component and the intensity of the haze noise component are estimated based on the electrical signal corresponding to the light received by the light receiving unit, and the amount of the irradiation light is adjusted based on the estimation result. Therefore, the intensity of the irradiation light can be adjusted more accurately.

[0014] The control unit may estimate the intensities of the stationary noise component and the haze noise component from an electrical signal corresponding to light received by the light receiving unit when different intensities of the irradiation light are irradiated onto the one processing liquid flow path. Since the intensity of the haze noise component can vary depending on the intensity of the irradiation light, by estimating the intensities of the stationary noise component and the haze noise component based on the difference in light received by the light receiving unit when different intensities of the irradiation light are irradiated as described above, it is possible to more accurately estimate the relationship between the haze noise component and the stationary noise component.

[0015] In another exemplary embodiment, a foreign matter detection method is provided for a foreign matter detection device configured to detect foreign matter contained in a processing liquid for substrate processing, the foreign matter detection method including: irradiating, by an irradiation unit, each of a plurality of processing liquid flow paths through which the processing liquid to be supplied to a substrate flows, with irradiation light from a light source; and receiving, by a light receiving unit, light emitted from the processing liquid flow paths as a result of the irradiation of the irradiation light, wherein the irradiation unit uses a light adjusting unit to vary the light intensities of the irradiation light irradiating the plurality of processing liquid flow paths.

[0016] According to the above foreign matter detection method, the light emitted from the light source is irradiated onto the treatment liquid flow path after the light intensity is adjusted by the light adjustment unit included in the irradiation unit. At this time, if treatment liquids with different properties flow through the multiple treatment liquid flow paths or if the flow conditions such as flow velocity and flow rate are different, the light intensity of the light irradiated onto the multiple treatment liquid flow paths can be adjusted, thereby enabling efficient foreign matter detection according to the state of the treatment liquid in each treatment liquid flow path.

[0017] An embodiment will be described below with reference to the drawings. In the description, identical elements or elements having identical functions are given the same reference numerals, and duplicated explanations will be omitted. Some drawings show a Cartesian coordinate system defined by an X-axis, a Y-axis, and a Z-axis. In the following embodiment, the Z-axis corresponds to the vertical direction, and the X-axis and the Y-axis correspond to the horizontal direction.

[0018] [Substrate processing system] The substrate processing system 1 (substrate processing apparatus) shown in FIG. 1 is a system that forms a photosensitive coating on a workpiece W, exposes the photosensitive coating, and develops the photosensitive coating. The workpiece W to be processed is, for example, a substrate, or a substrate on which a film, circuit, or the like has been formed by undergoing a predetermined process. One example of a substrate included in the workpiece W is a wafer containing silicon. The workpiece W (substrate) may be formed in a circular shape. The workpiece W to be processed may be a glass substrate, a mask substrate, an FPD (Flat Panel Display), or the like, or may be an intermediate product obtained by undergoing a predetermined process on such a substrate. The photosensitive coating is, for example, a resist film.

[0019] The substrate processing system 1 includes a coating / developing apparatus 2 and an exposure apparatus 3. The exposure apparatus 3 is an apparatus that exposes a resist film (photosensitive coating) formed on a workpiece W (substrate). Specifically, the exposure apparatus 3 irradiates an exposure target portion of the resist film with energy rays using a method such as immersion exposure. The coating / developing apparatus 2 performs a process of forming a resist film by applying a resist (chemical solution) to the surface of the workpiece W before the exposure process by the exposure apparatus 3, and then performs a development process of the resist film after the exposure process.

[0020] (Substrate processing equipment) The following describes the configuration of a coating and developing apparatus 2 as an example of a substrate processing apparatus. As shown in Figures 1 and 2, the coating and developing apparatus 2 includes a carrier block 4, a processing block 5, an interface block 6, and a control device 18.

[0021] The carrier block 4 introduces the workpiece W into the coating and developing apparatus 2 and removes the workpiece W from the coating and developing apparatus 2. For example, the carrier block 4 can support a plurality of carriers C for the workpiece W and has a built-in transport device A1 including a transfer arm. The carrier C accommodates a plurality of circular workpieces W, for example. The transport device A1 removes the workpiece W from the carrier C and passes it to the processing block 5, and receives the workpiece W from the processing block 5 and returns it to the carrier C. The processing block 5 has a plurality of processing modules 11, 12, 13, and 14.

[0022] The processing module 11 incorporates a liquid processing unit U1, a heat processing unit U2, and a transport device A3 that transports the workpiece W to these units. The processing module 11 forms an underlayer film on the surface of the workpiece W using the liquid processing unit U1 and the heat processing unit U2. The liquid processing unit U1 applies a processing liquid for forming the underlayer film onto the workpiece W. The heat processing unit U2 performs various heat treatments associated with the formation of the underlayer film.

[0023] The processing module 12 incorporates a liquid processing unit U1, a heat processing unit U2, and a transport device A3 that transports the workpiece W to these units. The processing module 12 forms a resist film on the underlying film using the liquid processing unit U1 and the heat processing unit U2. The liquid processing unit U1 applies a processing liquid (resist) for forming the resist film onto the underlying film. The heat processing unit U2 performs various heat treatments associated with the formation of the resist film.

[0024] The processing module 13 incorporates a liquid processing unit U1, a heat processing unit U2, and a transport device A3 that transports the workpiece W to these units. The processing module 13 forms an upper layer film on the resist film using the liquid processing unit U1 and the heat processing unit U2. The liquid processing unit U1 applies a liquid for forming the upper layer film onto the resist film. The heat processing unit U2 performs various heat treatments associated with the formation of the upper layer film.

[0025] The processing module 14 incorporates a liquid processing unit U1, a heat processing unit U2, and a transport device A3 that transports the workpiece W to these units. The processing module 14 uses the liquid processing unit U1 and the heat processing unit U2 to perform development processing of the resist film that has been subjected to exposure processing and heat processing associated with the development processing. The liquid processing unit U1 applies a developer to the surface of the exposed workpiece W and then rinses it away with a rinse liquid, thereby performing development processing of the resist film. The heat processing unit U2 performs various heat processing associated with the development processing. Specific examples of heat processing include a heat processing before the development processing (PEB: Post Exposure Bake) and a heat processing after the development processing (PB: Post Bake).

[0026] A shelf unit U10 is provided on the carrier block 4 side within the processing block 5. The shelf unit U10 is divided into multiple cells arranged in the vertical direction. A transport device A7 including a lifting arm is provided near the shelf unit U10. The transport device A7 raises and lowers the workpiece W between the cells of the shelf unit U10.

[0027] A shelf unit U11 is provided on the interface block 6 side in the processing block 5. The shelf unit U11 is divided into a plurality of cells arranged in the vertical direction.

[0028] The interface block 6 transfers the workpiece W to and from the exposure apparatus 3. For example, the interface block 6 has a built-in transport device A8 including a transfer arm, and is connected to the exposure apparatus 3. The transport device A8 transfers the workpiece W placed on the shelf unit U11 to the exposure apparatus 3. The transport device A8 receives the workpiece W from the exposure apparatus 3 and returns it to the shelf unit U11.

[0029] The control device 18 controls the coating and developing device 2 to perform the coating and developing process, for example, in the following procedure: First, the control device 18 controls the transport device A1 to transport the workpiece W in the carrier C to the shelf unit U10, and then controls the transport device A7 to place the workpiece W in a cell for the processing module 11.

[0030] Next, the control device 18 controls the transport device A3 to transport the workpiece W on the shelf unit U10 to the liquid processing unit U1 and the heat processing unit U2 in the processing module 11. The control device 18 also controls the liquid processing unit U1 and the heat processing unit U2 to form an underlayer film on the surface of the workpiece W. Thereafter, the control device 18 controls the transport device A3 to return the workpiece W on which the underlayer film has been formed to the shelf unit U10, and controls the transport device A7 to place the workpiece W in a cell for the processing module 12.

[0031] Next, the control device 18 controls the transport device A3 to transport the workpiece W from the shelf unit U10 to the liquid processing unit U1 and the heat processing unit U2 in the processing module 12. The control device 18 also controls the liquid processing unit U1 and the heat processing unit U2 to form a resist film on the surface of the workpiece W. Thereafter, the control device 18 controls the transport device A3 to return the workpiece W to the shelf unit U10, and controls the transport device A7 to place the workpiece W in a cell for the processing module 13.

[0032] Next, the control device 18 controls the transport device A3 to transport the workpiece W on the shelf unit U10 to each unit in the processing module 13. The control device 18 also controls the liquid processing unit U1 and the heat processing unit U2 to form an upper layer film on the resist film of the workpiece W. Thereafter, the control device 18 controls the transport device A3 to transport the workpiece W to the shelf unit U11.

[0033] Next, the control device 18 controls the transport device A8 to send the workpiece W on the shelf unit U11 to the exposure device 3. Thereafter, the control device 18 controls the transport device A8 to receive the workpiece W that has been subjected to exposure processing from the exposure device 3 and place it in a cell for the processing module 14 in the shelf unit U11.

[0034] Next, the control device 18 controls the transport device A3 to transport the workpiece W on the shelf unit U11 to each unit in the processing module 14, and controls the liquid processing unit U1 and the heat processing unit U2 to perform a development process on the resist film on the workpiece W. Thereafter, the control device 18 controls the transport device A3 to return the workpiece W to the shelf unit U10, and controls the transport devices A7 and A1 to return the workpiece W into the carrier C. This completes the coating and developing process.

[0035] (liquid processing unit) Next, an example of the liquid processing unit U1 will be described in detail with reference to Figures 3 and 4. Here, the liquid processing unit U1 (processing liquid supply unit) in the processing module 12 that forms a resist film will be described as an example. As shown in Figure 3, the liquid processing unit U1 has a spin holder 20 and a processing liquid supply part 30.

[0036] The rotary holder 20 holds and rotates the workpiece W based on operational instructions from the control device 18. The rotary holder 20 has, for example, a holder 22 and a rotation drive unit 24. The holder 22 supports the center of the workpiece W, which is placed horizontally with its surface Wa facing up, and holds the workpiece W, for example, by vacuum suction or the like. The rotation drive unit 24 is an actuator including a power source such as an electric motor, and rotates the holder 22 around a vertical axis Ax. This causes the workpiece W on the holder 22 to rotate.

[0037] The processing liquid supply unit 30 supplies the processing liquid to the surface Wa of the workpiece W by ejecting the processing liquid toward the surface Wa based on the operational instructions of the control device 18. The processing liquid supplied by the processing liquid supply unit 30 is a substrate processing solution used to process the workpiece W. Examples of processing liquid include a solution (resist) used to form a resist film and a solution (e.g., thinner) used in a pre-wetting process to increase the wettability of the surface Wa to the resist. The processing liquid supply unit 30 has, for example, multiple nozzles 32, a holding head 34, and a supply unit 36.

[0038] The multiple nozzles 32 each eject a processing liquid onto the surface Wa of the workpiece W held by the holder 22. The multiple nozzles 32 are, for example, arranged above the workpiece W while being held by a holding head 34, and individually eject the processing liquid downward. The holding head 34 may be configured to be movable in a direction along the surface Wa of the workpiece W by a drive unit (not shown). The number of the multiple nozzles 32 is not limited, but the following description will be given taking as an example a case where the processing liquid supply unit 30 has 12 nozzles 32 (hereinafter referred to as "nozzles 32A to 32L").

[0039] The nozzles 32A to 32L are each supplied with a processing liquid from the supply unit 36. Different types of processing liquid may be supplied to the nozzles 32A to 32L from the supply unit 36. As an example, different types of resists are supplied to the nozzles 32A to 32J from the supply unit 36, and different types of thinners are supplied to the nozzles 32K and 32L from the supply unit 36.

[0040] 4, the supply unit 36 includes a plurality of supply pipes 42A-42L and a plurality of supply sources 44A-44L. The supply pipe 42A forms a flow path between the nozzle 32A and the supply source 44A, which is a source of the processing liquid to be supplied to (discharged from) the nozzle 32A. The supply source 44A includes, for example, a bottle that stores the processing liquid and a pump that pressure-feeds the processing liquid from the bottle toward the nozzle 32A. Similar to the supply pipe 42A, the supply pipes 42B-42L also form flow paths between the nozzles 32B-32L and the supply sources 44B-44L, which are sources of the processing liquid.

[0041] The supply unit 36 further includes a plurality of on-off valves V provided in the plurality of supply pipes 42A to 42L, respectively. The on-off valves V are switched between an open state and a closed state based on an operational instruction from the control device 18. By switching the on-off states of the plurality of on-off valves V, the flow paths of the supply pipes 42A to 42L are opened and closed, respectively. For example, when the on-off valve V is in the open state, the processing liquid flows in the flow paths of the supply pipes 42A to 42L, and is discharged from the nozzles 32A to 32L toward the surface Wa of the workpiece W.

[0042] (Foreign object detection unit) The coating and developing apparatus 2 further includes a foreign matter detection unit 50 (foreign matter detection device) configured to detect foreign matter (particles) contained in the processing liquid supplied to the workpiece W. The foreign matter detection unit 50 is configured, for example, to detect foreign matter in each of the processing liquids flowing through the flow paths of the plurality of supply pipes 42A-42L. The foreign matter detection unit 50 may be disposed near the liquid processing unit U1 or may be disposed inside the housing of the liquid processing unit U1. Some elements of the foreign matter detection unit 50 may be provided between the on-off valve V and the nozzles 32A-32L on the flow paths of the supply pipes 42A-42L. An example of the foreign matter detection unit 50 will be described below with reference to FIGS. 5 to 11.

[0043] The foreign matter detection unit 50 forms flow paths (hereinafter referred to as "treatment liquid flow paths") through which the treatment liquids flowing through the supply pipes 42A-42L are respectively circulated. The foreign matter detection unit 50 detects foreign matter in the treatment liquid flowing through the treatment liquid flow paths by irradiating the treatment liquid flow paths with irradiation light (e.g., laser light) and receiving light generated in the treatment liquid flow paths. As shown in FIG. 5, the foreign matter detection unit 50 includes, for example, a housing 52, a flow path forming section 60, and a measurement section 70. The housing 52 includes a top wall 54a, a bottom wall 54b, and side walls 56a-56d. As an example, the top wall 54a and the bottom wall 54b are each disposed horizontally (along the XY plane). Furthermore, the side walls 56a, 56b are each disposed vertically (along the YZ plane) along the Y-axis direction and face each other in the X-axis direction (first direction). The side walls 56c and 56d are disposed vertically along the X-axis direction (along the XZ plane) and face each other in the Y-axis direction (second direction). The housing 52 houses the flow path forming section 60 and the measurement section .

[0044] The flow path forming unit 60 forms a plurality of treatment liquid flow paths provided on the flow paths of the supply pipes 42A to 42L, respectively. Each of the plurality of treatment liquid flow paths formed by the flow path forming unit 60 is used to detect foreign matter contained in the treatment liquid flowing through the corresponding treatment liquid flow path. For example, as shown in FIG. 6, the flow path forming unit 60 has a plurality of treatment liquid flow path forming units 62A to 62L. The plurality of treatment liquid flow path forming units 62A to 62L have the same configuration. Below, the treatment liquid flow path forming units will be described in detail using the treatment liquid flow path forming unit 62A as an example.

[0045] 5, the processing liquid flow path forming unit 62A forms a processing liquid flow path 64 on the flow path of the supply pipe 42A that connects the supply source 44A and the nozzle 32A (see also FIG. 4). The upstream and downstream ends of the processing liquid flow path 64 are connected to the supply pipe 42A. As a result, the processing liquid pressure-fed from the supply source 44A passes through a part of the flow path of the supply pipe 42A, the processing liquid flow path 64 of the processing liquid flow path forming unit 62A, and the remaining part of the flow path of the supply pipe 42A, in that order, before being ejected from the nozzle 32A onto the surface Wa of the workpiece W.

[0046] The processing liquid flow path forming portion 62A includes, for example, a block main body 66 in which the processing liquid flow path 64 is formed. The block main body 66 is made of a material that is transmissive to laser light used for foreign matter detection. Examples of materials that can form the block main body 66 include quartz and sapphire. The block main body 66 may be formed in a rectangular parallelepiped shape, and one surface of the block main body 66 may face the side wall 56a. As an example, an inlet 64a and an outlet 64b of the processing liquid flow path 64 are formed on the surface of the block main body 66 that faces the side wall 56a. The inlet 64a may be located below the outlet 64b.

[0047] The processing liquid flow path 64 includes, for example, a first flow path 68a, a second flow path 68b, and a third flow path 68c. The first flow path 68a is formed to extend horizontally (along the X-axis direction in the drawing) along the bottom wall 54b. One end of the first flow path 68a close to the side wall 56a constitutes the inlet 64a, and the other end of the first flow path 68a close to the side wall 56b is connected to the second flow path 68b. The second flow path 68b is formed to extend vertically along the side wall 56a (along the Z-axis direction). One end of the second flow path 68b close to the bottom wall 54b is connected to the first flow path 68a, and the other end of the second flow path 68b close to the top wall 54a is connected to the third flow path 68c. The third flow path 68c is formed to extend horizontally (along the X-axis direction) along the bottom wall 54b. One end of the third flow path 68c close to the side wall 56b is connected to the second flow path 68b, and the other end of the third flow path 68c close to the side wall 56a forms the outlet 64b.

[0048] The inlet 64a is connected to a supply pipe (hereinafter referred to as the "upstream supply pipe 46") that is upstream of the processing liquid flow path forming section 62A of the supply pipe 42A. The outlet 64b is connected to a supply pipe (hereinafter referred to as the "downstream supply pipe 48") that is downstream of the processing liquid flow path forming section 62A of the supply pipe 42A. The upstream supply pipe 46 and the downstream supply pipe 48 penetrate the side wall 56a that the block main body 66 faces. With the above configuration, the processing liquid delivered from the supply source 44A passes through the upstream supply pipe 46, first flow path 68a, second flow path 68b, third flow path 68c, and downstream supply pipe 48 in this order, and is supplied to the workpiece W from the nozzle 32A.

[0049] As described above, the treatment-liquid flow path forming sections 62A to 62L shown in FIG. 6 are configured similarly to one another. Therefore, like the treatment-liquid flow path forming section 62A, the treatment-liquid flow path forming sections 62B to 62L each include a block main body 66 having a treatment-liquid flow path 64 formed therein. The treatment-liquid flow path 64 of each of the treatment-liquid flow path forming sections 62B to 62L includes a first flow path 68a, a second flow path 68b, and a third flow path 68c. The upstream supply pipes 46 of the supply pipes 42B to 42L are connected to the inlets 64a (first flow paths 68a) of the treatment-liquid flow path forming sections 62B to 62L, respectively. The downstream supply pipes 48 of the supply pipes 42B to 42L are connected to the outlets 64b (third flow paths 68c) of the treatment-liquid flow path forming sections 62B to 62L, respectively.

[0050] The treatment liquid flow path forming portions 62A to 62L are arranged side by side in the direction from the side wall 56d to the side wall 56c (along the Y-axis direction) with each facing the side wall 56a. The treatment liquid flow path forming portions 62A to 62L may be arranged in this order with a gap between them. The height positions (positions in the Z-axis direction) of the first flow paths 68a of the treatment liquid flow path forming portions 62A to 62L may be approximately the same.

[0051] The distances (positions in the X-axis direction) of the second flow paths 68b from the side wall 56a of the treatment-liquid flow-path forming portions 62A to 62L may be approximately the same as each other. Also, the height positions (distances from the bottom wall 54b) of the third flow paths 68c of the treatment-liquid flow-path forming portions 62A to 62L may be approximately the same as each other.

[0052] The first flow paths 68a of the treatment liquid flow path forming sections 62A to 62L are arranged side by side along the Y-axis direction. The second flow paths 68b of the treatment liquid flow path forming sections 62A to 62L are arranged side by side along the Y-axis direction. The third flow paths 68c of the treatment liquid flow path forming sections 62A to 62L are arranged side by side along the Y-axis direction.

[0053] Returning to FIG. 5, the measurement unit 70 includes a light source 72, an irradiation unit 74, a light receiving unit 76, a holder 78, and a drive unit 80. The light source 72 generates laser light as irradiation light for detecting foreign matter in the treatment liquid. The light source 72 emits laser light, for example, with a wavelength of approximately 400 nm to 1000 nm and an output of approximately 600 mW to 1000 mW. For example, as shown in FIG. 7, the light source 72 is provided on the bottom wall 54b and disposed below the treatment liquid flow path forming units 62A to 62L. For example, the light source 72 emits laser light in a direction from the side wall 56d toward the side wall 56c (the negative direction of the Y axis). The light source 72 is disposed at a position different from the treatment liquid flow path forming unit 62A in the Y axis direction. The light source 72 is disposed spaced apart from the treatment liquid flow path forming unit 62A in the Y axis direction.

[0054] The irradiation unit 74 is configured to irradiate the irradiation light from the light source 72 toward each of the treatment liquid flow paths 64 of the treatment liquid flow path forming units 62A to 62L. The irradiation unit 74 is configured, for example, to individually irradiate the irradiation light toward each of the treatment liquid flow paths 64 of the treatment liquid flow path forming units 62A to 62L. The irradiation unit 74 may be disposed below the treatment liquid flow paths 64. The irradiation unit 74 includes an optical member 82 configured, for example, to change the direction of the irradiation light from the light source 72 so that the irradiation light is irradiated toward each of the treatment liquid flow paths 64.

[0055] The optical member 82 includes, for example, a reflecting member 82a, a condensing lens 82b, a neutral density filter 82c, and a trap unit 82d. The reflective surface of the reflecting member 82a faces the light source 72 in the Y-axis direction. The reflective surface of the reflecting member 82a reflects the irradiation light emitted substantially horizontally from the light source 72 upward. The condensing lens 82b is disposed above the reflecting member 82a and condenses the irradiation light reflected by the reflecting member 82a at a measurement position set in the treatment liquid flow path 64. The condensing lens 82b is configured, for example, to irradiate the irradiation light at a measurement position set in the first flow path 68a of the treatment liquid flow path 64. Note that the condensing position of the condensing lens 82b may be set taking into consideration that the path of the irradiation light may be changed by the neutral density filter 82c described below.

[0056] The neutral density filter 82c functions as a light-attenuating member that attenuates the light emitted from the condenser lens 82b and emits the light toward the treatment liquid flow path 64. That is, the neutral density filter 82c functions as a light adjusting unit that adjusts the amount of light emitted toward the treatment liquid flow path 64. For example, an ND (Neutral Density) filter can be used as the neutral density filter 82c. In this embodiment, an example is shown in which a reflective ND filter is used as the neutral density filter 82c. In the case of a reflective ND filter, a predetermined percentage of the incident light passes through the ND filter and is emitted toward the treatment liquid flow path 64, while a portion of the light is reflected by the filter. The trap unit 82d is provided on the optical path of the light reflected by the neutral density filter 82c. A beam trap that absorbs the irradiated light can be used as the trap unit 82d. For example, a beam splitter can be used as the reflective ND filter.

[0057] The neutral density filters 82c may be individually provided for the processing liquid flow paths 64 in the processing liquid flow path forming portions 62A to 62L, as shown in Fig. 7. The multiple neutral density filters 82c may be configured to be fixed to the side wall 56a via, for example, a support member 82e, as shown in Fig. 5.

[0058] Furthermore, the degree to which the neutral density filter 82c attenuates the irradiated light (light attenuation rate) may be changed, for example, depending on the characteristics of the processing liquid flowing through the processing liquid flow path 64. When adjusting the light attenuation rate of the neutral density filter 82c, for example, it can be set so that the amount of irradiated light emitted from the neutral density filter 82c toward the processing liquid flow path 64 becomes smaller within a range in which the performance for detecting foreign matter is not reduced due to the light attenuation. Details will be described later.

[0059] Although the above description has been given of the case where the neutral density filter 82c is an ND filter, the neutral density filter 82c may have optical characteristics related to light attenuation that are different from those of an ND filter. For example, the neutral density filter 82c may have optical characteristics that selectively attenuate light in a specific wavelength range. The optical characteristics of the filter to be selected may be changed within a range that allows the light receiving unit 76 to adequately detect the presence of foreign matter in the processing liquid.

[0060] When the neutral density filters 82c are individually provided for the processing liquid flow paths 64 in the processing liquid flow path forming sections 62A to 62L, the neutral density filters 82c may have different light attenuation rates. When the same type of processing liquid flows through the processing liquid flow paths 64 in the processing liquid flow path forming sections 62A to 62L, the neutral density filters 82c corresponding to the processing liquid flow paths 64 may have the same light attenuation rate. On the other hand, when different types of processing liquids flow through the processing liquid flow paths 64, neutral density filters 82c having light attenuation rates according to the types of processing liquid may be provided.

[0061] Furthermore, when the neutral density filters 82c are individually provided for the processing liquid flow paths 64 in the processing liquid flow path forming portions 62A to 62L, the neutral density filters 82c may be configured to have different optical characteristics other than the light attenuation rate. Examples of optical characteristics other than the light attenuation rate include polarization characteristics. Furthermore, filters may be configured to have different light attenuation characteristics according to wavelength.

[0062] The holder 78 movably holds each of the components of the optical member 82 (the reflecting member 82a, the condenser lens 82b, and the trap unit 82d) other than the neutral density filter 82c. The holder 78 has, for example, a guide rail 88 and a slide base 84. The guide rail 88 may be provided on the bottom wall 54b and formed to extend in a direction from the side wall 56c toward the side wall 56d (along the Y-axis direction). For example, as shown in FIG. 7, the guide rail 88 may extend in the Y-axis direction at least to the treatment liquid flow path forming units 62A to 62L. The guide rail 88 movably supports the slide base 84.

[0063] The slide base 84 is disposed below the treatment liquid flow path forming portions 62A to 62L and supports the optical member 82 (e.g., the reflecting member 82a). The slide base 84 is formed to extend in a direction intersecting the guide rails 88 (e.g., the X-axis direction), as shown in FIG. 5 or 7, for example. For example, when viewed from the side, one end of the slide base 84 close to the side wall 56a is located below the treatment liquid flow path forming portion 62A, and the other end close to the side wall 56b is located closer to the side wall 56b than the treatment liquid flow path forming portion 62A. As an example, the member of the optical member 82 that is held by the holder 78 is disposed at one end of the slide base 84 close to the side wall 56a.

[0064] The driving unit 80 uses a power source such as an electric motor to move the slide table 84 along the guide rails 88. As the slide table 84 moves along the guide rails 88, the irradiation unit 74 (the member of the optical member 82 that is held by the holding unit 78) moves along the Y-axis direction.

[0065] The light receiving unit 76 is configured to receive light emitted from the treatment liquid flow path 64 in response to irradiation with irradiation light from the irradiation unit 74. The light receiving unit 76 may be disposed so as to sandwich the treatment liquid flow path forming portions 62A to 62L between itself and the side wall 56a.

[0066] The light receiving unit 76 includes, for example, an optical member 92 and a light receiving element 94. In the direction from the side wall 56a toward the side wall 56b (the X-axis direction), the treatment liquid flow path forming portion 62A, the optical member 92, and the light receiving element 94 are arranged in this order. The height positions of the optical member 92 and the light receiving element 94 may, for example, approximately coincide with the height position of the first flow path 68a of the treatment liquid flow path 64.

[0067] The optical member 92 includes, for example, a condenser lens that condenses light emitted from the treatment liquid flow path 64 toward the light receiving element 94. A wavelength filter that passes only light having a specific wavelength may be provided inside the optical member 92. The light receiving element 94 receives the light condensed by the optical member 92 and generates an electrical signal corresponding to the received light (detection light). The light receiving element 94 includes, for example, a photodiode that performs photoelectric conversion.

[0068] The optical member 92 and the light receiving element 94 are attached to a support member 86 that extends in the vertical direction. The support member 86 is connected to the slide base 84. For example, the lower end of the support member 86 is connected to the end of the slide base 84 opposite to the end where the optical member 82 is provided. As the drive unit 80 moves the slide base 84, the optical member 92 and the light receiving element 94 move along the Y-axis direction.

[0069] With the above configuration, the drive unit 80 moves the slide base 84, thereby moving both the irradiation unit 74 (including the optical member 82 held by the holder 78) and the light-receiving unit 76 along the Y-axis direction. The drive unit 80 moves the irradiation unit 74 and the light-receiving unit 76, for example, between a position where the irradiation unit 74 and the light-receiving unit 76 face the treatment-liquid flow path forming unit 62A, and a position where the irradiation unit 74 and the light-receiving unit 76 face the treatment-liquid flow path forming unit 62L. Hereinafter, the positions where the irradiation unit 74 and the light-receiving unit 76 face one of the treatment-liquid flow path forming units will be referred to as the positions corresponding to that treatment-liquid flow path forming unit.

[0070] As an example, while the light source 72 continues to irradiate the optical member 82, the drive unit 80 moves the optical member 82 below one of the treatment liquid flow paths 64 of the treatment liquid flow path forming units 62A to 62L, whereby the treatment liquid flow path 64 is irradiated with the irradiation light from the irradiation unit 74. The irradiation light irradiated to the treatment liquid flow path 64 is light that has been attenuated by a neutral density filter 82c provided below the treatment liquid flow path 64. During irradiation with the irradiation light, the light receiving element 94 receives the light emitted from the treatment liquid flow path 64.

[0071] As described above, the irradiation unit 74 is disposed below the measurement position set in the treatment liquid flow path 64, and the light receiving unit 76 is disposed to the side of the measurement position. Therefore, when the treatment liquid flow path 64 is irradiated with irradiation light, the light receiving unit 76 receives a portion of light (scattered light) generated by scattering the irradiation light at the measurement position in the treatment liquid flow path 64. When irradiation light is irradiated into the treatment liquid flow path 64 through which a solution such as a treatment liquid flows, scattered light is generated due to the components of the treatment liquid, regardless of the presence or absence of foreign matter. If the solution does not contain foreign matter, most of the irradiation light passes through the treatment liquid flow path 64. On the other hand, if foreign matter is present in the solution, the degree of scattering of the irradiation light in the treatment liquid flow path 64 increases, and the intensity of the light received by the light receiving unit 76 (a portion of the scattered light directed toward the light receiving unit 76) becomes greater than when no foreign matter is present.

[0072] 7, the foreign object detection unit 50 may further include a heat sink 58. The heat sink 58 may be provided outside the housing 52. For example, the heat sink 58 may be provided at a position on the outer surface of the bottom wall 54b corresponding to the light source 72. The heat sink 58 may be a water-cooled heat sink. The heat sink 58 prevents a temperature rise inside the housing 52 caused by optical components such as the light source 72. This reduces the effect of heat generated by optical components such as the light source 72 on the processing liquid (substrate processing).

[0073] The foreign object detection unit 50 may further include a control unit 100. The control unit 100 controls each element of the foreign object detection unit 50. The control unit 100 is disposed inside the housing 52, for example.

[0074] 8, the control unit 100 has, as functional components (hereinafter referred to as "functional modules"), for example, a signal acquisition unit 102, a foreign substance determination unit 104, a processing information acquisition unit 106, a drive control unit 108, and an output unit 110. The control unit 100 further has a noise evaluation unit 112 and a light amount adjustment unit 114. Note that the processes executed by the signal acquisition unit 102, the foreign substance determination unit 104, the processing information acquisition unit 106, the drive control unit 108, the output unit 110, the noise evaluation unit 112, and the light amount adjustment unit 114 correspond to the processes executed by the control unit 100.

[0075] The signal acquiring unit 102 acquires an electrical signal corresponding to the intensity of the detection light from the light receiving unit 76. For example, the signal acquiring unit 102 acquires an electrical signal corresponding to the intensity of light emitted from the treatment liquid flow path 64 (first flow path 68a) through which the treatment liquid to be monitored flows among the treatment liquid flow path forming units 62A to 62L, from the light receiving element 94. For example, the signal acquiring unit 102 acquires an electrical signal having an amplitude corresponding to the intensity of the detection light.

[0076] The foreign matter determination unit 104 detects the presence or absence of foreign matter in the processing liquid based on the intensity, such as the amplitude, of an electrical signal corresponding to the detection light (hereinafter referred to as "signal intensity"). FIG. 9 shows a graph illustrating an example of the change over time in the signal intensity obtained from the signal acquisition unit 102. For example, as shown in FIG. 9, the foreign matter determination unit 104 determines that foreign matter is contained in the processing liquid when the signal intensity is greater than a predetermined threshold Th. The foreign matter determination unit 104 determines that foreign matter is not contained in the processing liquid when the signal intensity is equal to or less than the predetermined threshold Th. The threshold Th is a value that is set in advance in consideration of the intensity of scattered light when the irradiated light is scattered by foreign matter in the processing liquid.

[0077] The noise evaluation unit 112 identifies noise components from an electrical signal corresponding to the intensity of the detected light. The light intensity adjustment unit 114 has a function of adjusting the intensity of light irradiated onto the treatment liquid based on the results of the noise component identification by the noise evaluation unit 112.

[0078] The adjustments made by the noise evaluation unit 112 and the light intensity adjustment unit 114 will be described with reference to FIGS. 9 and 10. As shown in FIG. 9, the signal intensity obtained from the signal acquisition unit 102 includes not only those exceeding the threshold value Th but also noise components N that fluctuate below the threshold value Th. The noise components N may include instrument noise and haze noise. Instrument noise is a fixed component derived from the electrical circuitry of the device, and may be noise of a constant intensity regardless of the intensity of light irradiated onto the treatment liquid flow path 64. Therefore, in this embodiment, instrument noise may be referred to as stationary noise.

[0079] On the other hand, haze noise is a component that is generated due to components of the processing liquid, etc. As described above, when irradiation light is irradiated into the processing liquid flow path 64 through which a solution such as the processing liquid flows, scattered light is generated due to the components of the processing liquid, regardless of the presence or absence of foreign matter. When this scattered light due to the components of the processing liquid is incident on the light-receiving element 94, the electrical signal transmitted from the light-receiving element 94 corresponds to haze noise. Because haze noise is not an electrical signal indicating the presence of foreign matter, a threshold value Th for determining the presence or absence of foreign matter can be set so that haze noise is not detected as a detection result for foreign matter.

[0080] The scattered light emitted from the treatment liquid flow path 64 when the foreign matter is irradiated with the irradiation light and the above-mentioned haze noise are both light generated by the irradiation light, and therefore their signal intensities can change depending on the intensity of the irradiation light. Figure 10 shows a schematic diagram of how the signal intensities of each noise and the intensity of the electrical signal indicating the presence of foreign matter change when the intensity of the irradiation light to the treatment liquid flow path 64 is changed.

[0081] FIG. 10(a) shows a state in which three signals PS1 to PS3 related to foreign matter are detected based on light from the processing liquid flow path 64. FIG. 10(a) also shows instrument noise and haze noise. The dashed line indicating the instrument noise level and the solid line indicating the haze noise level in FIG. 10(a) indicate that noise with amplitudes of approximately these levels may occur. The example shown in FIG. 10(a) shows a situation in which the haze noise level is high relative to the instrument noise level. Of the three signals PS1 to PS3, signal PS3 is buried in the haze noise, and therefore, in reality, signal PS3 is not recognized as a signal derived from a foreign matter by the foreign matter determination unit 104, but may be recognized as part of the noise. In other words, in the example shown in FIG. 10(a), only signals PS1 and PS2 may be recognized as signals indicating the detection of a foreign matter.

[0082] When the intensity of the irradiated light irradiated onto the treatment liquid flow path 64 is reduced, the intensities of the signals PS1 to PS3 also decrease. FIG. 10(b) shows how the intensity of the signals detected based on the light from the treatment liquid flow path 64 changes when the intensity of the irradiated light is reduced. Comparing FIGS. 10(a) and 10(b) clearly shows that when the intensity of the irradiated light is reduced, the signals PS1 to PS3 and the haze noise level all decrease. However, because the intensity of scattered light is proportional to the intensity of the irradiated light, the signal intensities also change while maintaining a proportional relationship as the irradiated light changes. Therefore, when the irradiated light is weakened, as shown in FIG. 10(b), the signal intensities of the signals PS1 to PS3 and the haze noise level decrease while the intensity relationship between them is roughly maintained. Therefore, even if the intensity of the irradiated light is reduced until the haze noise level is roughly equivalent to the instrument noise level, the signals PS1 and PS2 can be distinguished from the noise components (haze noise and instrument noise), and detection accuracy can be maintained.

[0083] On the other hand, if the intensity of the irradiated light were reduced to the point where the haze noise level was lower than the equipment noise level, the signal PS2 might be mixed with noise components, potentially reducing the accuracy of foreign matter detection. Therefore, the minimum light intensity of the irradiated light while maintaining detection accuracy is set to the condition where the haze noise level is approximately equal to the equipment noise level. The light intensity is then adjusted using the neutral density filter 82c or the like so that the irradiated light can be applied to the treatment liquid flow path 64 under these conditions.

[0084] The noise evaluation unit 112 and the light intensity adjustment unit 114 described above have the function of adjusting the intensity of light irradiated onto the treatment liquid flow path 64 using the above-mentioned techniques. Specifically, the noise evaluation unit 112 has the function of identifying a haze noise component and an equipment noise component from the measurement results of the signal intensity that have already been measured. Furthermore, the light intensity adjustment unit 114 has the function of calculating the attenuable intensity of irradiated light based on the components identified by the noise evaluation unit 112.

[0085] The noise evaluation unit 112 can distinguish between haze noise components and instrument noise components, for example, by using two measurements taken under different light intensity conditions while the same type of processing liquid is flowing through the same processing liquid flow path 64. As described above, the haze noise component can vary depending on the intensity of the irradiated light. Therefore, it is possible to determine whether the level of the haze noise component N is greater than the level of the instrument noise component N by determining whether the noise component N varies with the light intensity. Alternatively, the light intensity adjustment unit 114 may repeatedly perform measurements while decreasing the intensity of the irradiated light and determine the state where the fluctuation of the noise component N becomes small as the minimum intensity of the irradiated light. Alternatively, a state where the light intensity is slightly increased compared to the minimum intensity may be set as the appropriate intensity of the irradiated light. In this way, the noise evaluation unit 112 and the light intensity adjustment unit 114 can determine the relationship between the haze noise component and the instrument noise component and set the intensity of the reduced irradiated light within a range where the instrument noise component does not affect the accuracy of foreign matter detection.

[0086] The results of the light intensity adjustment by the noise evaluation unit 112 and the light intensity adjustment unit 114 may be output from the output unit 110 to the control device 18. Furthermore, the light intensity may be adjusted by controlling the drive control unit 108 based on the results of the light intensity adjustment by the noise evaluation unit 112 and the light intensity adjustment unit 114.

[0087] Processing information acquiring unit 106 acquires information on processing performed in liquid processing unit U1 (hereinafter referred to as "processing information") from control device 18. The processing information includes, for example, information indicating the nozzles (processing liquids to be monitored) from which discharge is performed in liquid processing unit U1, and information indicating the timing and duration of supply of the processing liquid. Processing information acquiring unit 106 may acquire processing information from control device 18 for each process using one processing liquid before the supply of the processing liquid starts.

[0088] The drive control unit 108 moves the irradiation unit 74 and the light receiving unit 76 between the treatment-liquid flow-channel forming units 62A-62L by moving the slide table 84 using the drive unit 80. For example, in accordance with the treatment liquid indicated by the treatment information, the drive control unit 108 moves the irradiation unit 74 and the light receiving unit 76 using the drive unit 80 to positions in the treatment-liquid flow-channel forming units 62A-62L corresponding to the treatment-liquid flow channel 68 through which the treatment liquid passes. For example, when the treatment-liquid flow channel 64 is not being irradiated with irradiation light, the drive control unit 108 moves the irradiation unit 74 and the light receiving unit 76 using the drive unit 80 to a predetermined standby position. In one example, the standby position may be set to a position that does not overlap with the treatment-liquid flow-channel forming units 62A-62L.

[0089] The drive control unit 108 controls the drive unit 80 so that the irradiation light is irradiated onto the treatment liquid flow path 68 during at least a portion of the period during which the treatment liquid is supplied to the workpiece W. The drive control unit 108 controls the drive unit 80 so that the irradiation light is irradiated toward a position different from the treatment liquid flow path 64 of the treatment liquid flow path forming units 62A to 62L at the standby position during at least a portion of the period during which no treatment liquid is supplied to the workpiece W.

[0090] The output section 110 outputs the determination result by the foreign matter determination section 104 to the outside of the foreign matter detection unit 50. The output section 110 may output the determination result to the control device 18, or may output the determination result to a display or the like that notifies an operator of the result. For example, when the foreign matter determination section 104 determines that a foreign matter is contained in the processing liquid being monitored, the output section 110 may output an alarm signal indicating that a foreign matter is contained in the processing liquid being monitored. Furthermore, the output section 110 may output the results of the light amount adjustment by the noise evaluation section 112 and the light amount adjustment section 114 to the control device 18.

[0091] The control unit 100 is configured with one or more control computers. For example, the control unit 100 has a circuit 200 shown in FIG. 11. The circuit 200 has one or more processors 202, a memory 204, a storage 206, an input / output port 208, and a timer 212. The storage 206 has a computer-readable storage medium, such as a hard disk. The storage medium stores a program for causing the control unit 100 to execute an operation checking method, which will be described later. The storage medium may be a removable medium, such as a non-volatile semiconductor memory, a magnetic disk, or an optical disk. The memory 204 temporarily stores the program loaded from the storage medium of the storage 206 and the results of calculations performed by the processor 202.

[0092] The processor 202 configures each functional module by executing the above programs in cooperation with the memory 204. The input / output port 208 inputs and outputs electrical signals between the control device 18, the light receiving unit 76, the drive unit 80, etc., in accordance with instructions from the processor 202. The timer 212 measures elapsed time, for example, by counting reference pulses at a fixed interval. Note that the hardware configuration of the control unit 100 is not necessarily limited to one in which each functional module is configured by a program. For example, each functional module of the control unit 100 may be configured by a dedicated logic circuit or an ASIC (Application Specific Integrated Circuit) that integrates such logic circuits.

[0093] [Foreign object detection method] Next, a foreign object detection method (foreign object detection procedure) executed in the foreign object detection unit 50 will be described with reference to Fig. 12. Fig. 12 is a flowchart showing an example of the foreign object detection method.

[0094] While irradiation of irradiation light from the light source 72 continues, for example, when the processing information acquisition unit 106 acquires processing information from the control device 18, the control unit 100 executes step S01. In step S01, for example, the drive control unit 108 moves the slide table 84 using the drive unit 80 to a position corresponding to the processing liquid flow path 64 through which the processing liquid to be monitored indicated by the processing information flows, thereby moving the irradiation unit 74 and the light receiving unit 76. As a result, irradiation light is irradiated from the irradiation unit 74 onto the processing liquid flow path 64 through which the processing liquid to be monitored flows, and the light emitted from the processing liquid flow path 64 is received by the light receiving unit 76.

[0095] Next, the control unit 100 executes steps S02 and S03. In step S02, for example, the signal acquisition unit 102 acquires a signal intensity corresponding to the detection light received by the light receiving unit 76. In step S03, for example, the foreign matter determination unit 104 determines whether the signal intensity obtained in step S02 is greater than a threshold value Th. If it is determined in step S03 that the signal intensity is greater than the threshold value Th (step S03: YES), the control unit 100 executes step S04. In step S04, for example, the output unit 110 outputs an alarm signal indicating that the processing liquid being monitored contains foreign matter. On the other hand, if it is determined in step S03 that the signal intensity is equal to or less than the threshold value Th (step S03: NO), the control unit 100 does not execute step S04.

[0096] Next, the control unit 100 executes step S05. In step S05, for example, the control unit 100 determines whether the supply of the processing liquid to be monitored has ended. The control unit 100 may determine whether the supply of the processing liquid has ended by measuring the elapsed time from the supply start timing included in the processing information. If it is determined in step S05 that the supply of the processing liquid to be monitored has not ended (step S05: NO), the control unit 100 repeats the processes of steps S02 and S03. As a result, monitoring of whether foreign matter is contained in the processing liquid continues during the supply period of the processing liquid.

[0097] If it is determined in step S05 that the supply of the processing liquid to be monitored has ended (step S05: YES), the control unit 100 executes step S06. In step S06, for example, the control unit 100 determines whether or not there is a waiting time based on the supply start timing for the next processing liquid to be monitored (hereinafter referred to as the "next supply start timing"). As an example, if the time until the next supply start timing is longer than a predetermined time, it is determined that there is a waiting time, and the control unit 100 executes step S07. In step S07, for example, the drive control unit 108 causes the drive unit 80 to move the irradiation unit 74 and the light receiving unit 76 to their waiting positions.

[0098] Next, the control unit 100 executes step S08. In step S08, for example, the control unit 100 waits until it is time to start monitoring the next processing liquid to be monitored. For example, the control unit 100 waits until the time until the next supply start timing becomes shorter than the above-mentioned predetermined time. If it is time to start monitoring the next processing liquid to be monitored in step S08 (step S08: YES), or if it is determined in step S06 that there is no waiting time (step S06: NO), the control unit 100 repeats the processes of steps S01 to S06.

[0099] [How to adjust the light intensity] Next, a method for adjusting the amount of light executed in the foreign object detection unit 50 will be described with reference to Fig. 13. Fig. 13 is a flowchart showing an example of the method for adjusting the amount of light.

[0100] First, the control unit 100 executes step S11. In step S11, for example, the drive control unit 108 moves the slide table 84 using the drive unit 80 to a position corresponding to the processing liquid flow path 64 through which the processing liquid to be monitored indicated by the processing information flows, thereby moving the irradiation unit 74 and the light receiving unit 76. As a result, the irradiation unit 74 irradiates the processing liquid flow path 64 through which the processing liquid to be monitored flows, and the light receiving unit 76 receives the light emitted from the processing liquid flow path 64. Then, the signal acquisition unit 102 acquires a signal intensity corresponding to the detection light received by the light receiving unit 76. The measurement result obtained in this manner is the measurement result at a specific light intensity. If necessary, the control unit 100 repeats step S11 to acquire measurement results under multiple conditions with different light intensities.

[0101] Next, the control unit 100 executes step S12. In step S12, for example, the noise evaluation unit 112 identifies the instrument noise component and the haze noise component based on the signal intensity information obtained in step S11. As an example, as described above, the level of the haze noise component may be identified based on whether there is a difference in the level of the noise component N in the results of measurement conditions using two levels of light intensity. Note that in step S12, the instrument noise component and the haze noise component do not need to be clearly distinguished from each other. As an example, in step S12, the level of the noise component N may be identified. Furthermore, if the magnitude of the instrument noise component is known, for example, if the noise component N is larger than the magnitude of the instrument noise component, this indicates that the haze noise component is larger than the instrument noise component. The haze noise component may be estimated from such information. The noise component N may also be measured directly from the result when the light intensity is set to zero.

[0102] Next, the control unit 100 executes step S13. In step S13, for example, the light amount adjustment unit 114 determines whether the instrument noise level and the haze noise level are substantially the same in the measurement results at a specific light amount. While the instrument noise level is constant, the haze noise level varies depending on the light amount. Therefore, whether the instrument noise level and the haze noise level are substantially the same may be determined based on whether the level of the noise component N changes when the light amount is changed (decreased).

[0103] If the haze noise level is higher than the equipment noise level (step S13: NO), it is determined that there is room for reducing the haze noise level. In this case, in step S14, for example, the light intensity adjustment unit 114 of the control unit 100 may set the light intensity of the irradiation light irradiated onto the treatment liquid flow path 64 to be one level lower. Also, the above steps S11 to S13 may be repeated under the condition that the light intensity is reduced by one level.

[0104] If the haze noise level is equivalent to the equipment noise level (step S13: YES), it is determined that there is no room for reducing the haze noise level. In this case, in step S15, for example, the light intensity adjustment unit 114 of the control unit 100 may estimate that the light intensity of the irradiation light irradiated onto the treatment liquid flow path 64 is the minimum condition. Furthermore, in step S16, for example, the light intensity adjustment unit 114 may set a condition in which the light intensity is slightly increased from this minimum condition as the measurement condition. Note that the measurement condition refers to the light intensity when detecting foreign matter in the treatment liquid. The minimum light intensity condition may be used as the measurement condition, but a condition in which the light intensity is slightly increased from the minimum condition may also be used, taking into account slight changes in the light intensity, etc.

[0105] 13 may be performed for each treatment liquid. Since the components in the treatment liquid vary depending on the treatment liquid, the level of haze noise may also vary. The light intensity may also be adjusted for each treatment liquid flow path 64. Since the level of haze noise may vary depending on the treatment liquid flow path 64, for example, performing the above procedure for each treatment liquid flow path 64 allows for more precise adjustment of the light intensity.

[0106] [Another example of a dimming component] FIG. 14 is a diagram showing another example of a light-attenuating member that functions as a light adjusting unit. FIG. 14 shows an example in which a beam splitter 82f, which is a light-attenuating member, is provided on the light path instead of the reflecting member 82a. In this case, a portion of the light split by the beam splitter 82f is emitted toward the treatment liquid flow path 64. Note that the other portion of the light split by the beam splitter 82f (light traveling in a direction different from the treatment liquid flow path 64) may be absorbed by a trap unit (not shown). In the configuration shown in FIG. 14, like other members included in the irradiation unit 74, the beam splitter 82f is held by the holder 78 and moves in the Y-axis direction as the slide table 84 moves along the guide rails 88.

[0107] In this way, the configuration and arrangement of the light-attenuating member may be changed as appropriate. As another configuration for the light-attenuating member, for example, a configuration in which a light-attenuating member is arranged between the light source 72 and the reflecting member 82a may be used. Alternatively, a configuration in which one of a plurality of light-attenuating members having different optical characteristics can be selected and arranged in the optical path may be used. In this case, for example, a configuration in which a plurality of light-attenuating members are installed in a revolver and one of the light-attenuating members is arranged in the optical path by rotating the revolver may be adopted. Alternatively, a plurality of light-attenuating members may be arranged in the optical path, and a configuration in which the irradiated light is optimized by using a plurality of light-attenuating members may be used.

[0108] Furthermore, the light source 72 itself may be configured to have a light adjustment function. As an example, the intensity of the light emitted from the light source 72 may be adjustable. Since the foreign matter detection unit 50 can be provided with various light-reducing member configurations as described above, these may be combined to adjust the amount of light irradiated onto the treatment liquid flow path 64.

[0109] [Effect] According to the above-described foreign matter detection device and foreign matter detection method, the light emitted from the light source 72 has its light intensity adjusted by the neutral density filter 82c (or beam splitter 82f) functioning as a light adjustment unit included in the irradiation unit 74, and is then irradiated onto the treatment liquid flow path 64. The light intensity of the light irradiated onto the plurality of treatment liquid flow paths 64 can be adjusted. Therefore, when treatment liquids with different properties flow through the plurality of treatment liquid flow paths or when the flow conditions such as flow velocity and flow rate are different, the light intensity of the light irradiated onto the plurality of treatment liquid flow paths can be adjusted, thereby enabling efficient foreign matter detection according to the state of the treatment liquid in each treatment liquid flow path 64.

[0110] The irradiation unit 74 may be configured to move relatively to the plurality of treatment liquid flow paths 64, thereby being able to irradiate irradiation light toward each of the plurality of treatment liquid flow paths 64. Furthermore, the light adjustment unit may be provided on an optical path toward each of the plurality of treatment liquid flow paths 64. In this case, it is possible to individually adjust the light intensity for each treatment liquid flow path, thereby enabling flexible adjustment of the light intensity.

[0111] The light adjusting unit may adjust the intensity of the irradiation light based on a noise component contained in the light received by the light receiving unit 76 when the irradiation light is applied to one of the multiple processing liquid flow paths 64. Specifically, the light adjusting unit may adjust the intensity of the irradiation light applied to one processing liquid flow path 64 so that the intensity of the haze noise component, which varies depending on the intensity of the irradiation light, approaches the intensity of the stationary noise component, provided that the intensity does not fall below the intensity of the stationary noise component that occurs regardless of the intensity of the irradiation light. Of the noise components contained in the light received by the light receiving unit 76, the haze noise component varies depending on the intensity of the irradiation light. Therefore, by adjusting the intensity of the irradiation light to approach the intensity of the stationary noise component, the intensity of the irradiation light can be adjusted to be lower while preventing a decrease in the accuracy of foreign matter detection, thereby enabling efficient foreign matter detection according to the state of the processing liquid.

[0112] The optical system may further include a control unit 100 that acquires an electrical signal corresponding to the intensity of light received by the light receiving unit 76. In this case, the control unit 100 may estimate the intensity of the stationary noise component and the intensity of the haze noise component based on the electrical signal corresponding to the light received by the light receiving unit 76 when the irradiation light is irradiated onto one of the processing liquid flow paths 64. Furthermore, the light adjusting unit may adjust the amount of the irradiation light irradiated onto one of the processing liquid flow paths 64 based on the estimation result by the control unit 100 so that the intensity of the haze noise component, which varies depending on the intensity of the irradiation light, approaches the intensity of the stationary noise. With the above configuration, the intensity of the stationary noise component and the intensities of the haze noise component are estimated based on the electrical signal corresponding to the light received by the light receiving unit 76, and the amount of the irradiation light is adjusted based on the estimation result. Therefore, the intensity of the irradiation light can be adjusted more accurately.

[0113] The control unit 100 may be configured to estimate the intensities of the stationary noise component and the haze noise component from electrical signals corresponding to light received by the light receiving unit 76 when different intensities of irradiation light are irradiated onto one processing liquid flow path 64. The intensity of the haze noise component may vary depending on the intensity of the irradiation light. Therefore, by estimating the intensities of the stationary noise component and the haze noise component based on the difference in light received by the light receiving unit 76 when different intensities of irradiation light are irradiated, it becomes possible to more accurately estimate the relationship between the haze noise component and the stationary noise component.

[0114] [Variations] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various omissions, substitutions, and modifications may be made. Furthermore, elements in different embodiments may be combined to form other embodiments.

[0115] The foreign object detection procedure according to the above embodiment is an example, and the order of steps, execution timing, execution contents, etc. can be changed as appropriate.

[0116] The configuration of the foreign matter detection device can also be modified as appropriate. For example, at least a portion of the processing liquid flow path 64 flowing through the block main body 66 may be formed to extend in a direction other than the horizontal and vertical directions. The inlet 64a and outlet 64b of the processing liquid flow path 64 may be formed on different surfaces of the block main body.

[0117] The treatment liquid flow path forming portions 62A to 62L may include a liquid supply pipe through which the treatment liquid flows, instead of the block main body 66. The treatment liquid flow path 64 may be a flow path inside the liquid supply pipe. These liquid supply pipes may be made of a material that can transmit irradiated light (for example, quartz or sapphire). The foreign matter detection unit 50 may have a single treatment liquid flow path forming portion, instead of the treatment liquid flow path forming portions 62A to 62L.

[0118] The treatment liquid flow path forming sections 62A to 62L may be arranged along the Y-axis direction at substantially equal intervals from one another, or may be arranged at different intervals from one another. Furthermore, one or more dummy flow path forming sections that are not used for treatment may be arranged as part of the treatment liquid flow path forming sections.

[0119] The optical characteristics of the neutral density filter 82c can be selected according to the characteristics of the treatment liquid as described above. However, for example, a dummy filter, i.e., an optical filter without a neutral density function, may be disposed on the optical path to the treatment liquid flow path 64. For example, when the treatment liquid is thinner, there are cases where a neutral density member is not required. In this case, if a configuration is adopted in which no neutral density member is provided for multiple treatment liquid flow paths 64, there is a possibility that the optical path lengths will differ among the treatment liquid flow paths. In response to this, by disposing an optical filter without a neutral density function on the optical path in the same manner as the other treatment liquid flow paths 64, the optical path lengths can be made uniform.

[0120] The foreign matter detection unit 50 may include an irradiation driver that moves the irradiation unit 74 along the Y-axis direction, and a light-receiving driver that moves the light-receiving unit 76 along the Y-axis direction. These two drivers may be configured to move the irradiation unit 74 and the light-receiving unit 76 along the Y-axis direction. Furthermore, an X-axis direction driver that moves the light-receiving unit 76 along the X-axis direction may also be provided. The irradiation unit 74 may include a light source 72, and irradiation light may be irradiated onto each of the treatment liquid flow paths 64 without passing through the optical member 82.

[0121] The light receiving unit 76 may receive a portion of transmitted light obtained when the irradiation light from the irradiation unit 74 passes through the treatment liquid flow path 64. In this case, the irradiation unit 74 and the light receiving unit 76 may be arranged to sandwich the treatment liquid flow path forming units 62A to 62L between them in the vertical direction (Z-axis direction).

[0122] The specific configuration of the substrate processing apparatus is not limited to the configuration of the coating and developing apparatus 2 exemplified above. Any substrate processing apparatus may be used as long as it is equipped with a foreign matter detection unit 50 that detects foreign matters in a processing liquid supplied to a substrate. The processing liquid that is the target liquid for foreign matter detection by the foreign matter detection unit 50 may be a solution for forming a film other than a resist film (for example, the above-mentioned underlayer film or overlayer film), or may be a solution for substrate processing other than film formation. All or part of the functional modules of the control unit 100 of the foreign matter detection unit 50 may be executed by the control device 18. In this case, the foreign matter detection unit 50 and the control device 18 may constitute a foreign matter detection apparatus.

[0123] From the foregoing, it will be understood that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims. [Explanation of symbols]

[0124] 1...substrate processing system, 2...coating and developing apparatus, 3...exposure apparatus, 32, 32A to 32L...nozzle, 50...foreign matter detection unit (foreign matter detection apparatus), 52...housing, 54a...upper wall, 54b...bottom wall, 56a to 56d...side wall, 60...flow path forming section, 62A to 62L...processing liquid flow path forming section, 64...processing liquid flow path, 70...measuring section, 72...light source, 74...irradiation section, 76...light receiving section, 78...holding section, 80...driving section, 82...optical member, 82a ...Reflective member, 82b...Condenser lens, 82c...Neutral density filter, 82d...Trap section, 82e...Support member, 82f...Beam splitter, 84...Slide base, 86...Support member, 88...Guide rail, 92...Optical member, 94...Light receiving element, 100...Control section, 102...Signal acquisition section, 104...Foreign matter determination section, 106...Processing information acquisition section, 108...Drive control section, 110...Output section, 112...Noise evaluation section, 114...Light intensity adjustment section.

Claims

1. A foreign matter detection device configured to detect foreign matter contained in a processing liquid for substrate processing, comprising: a plurality of treatment liquid flow path forming sections each forming a plurality of treatment liquid flow paths through which the treatment liquid supplied to the substrate flows; an irradiation unit configured to individually irradiate irradiation light from a light source toward each of the plurality of treatment liquid flow paths; a light receiving unit configured to receive light emitted from the treatment liquid flow path by the irradiation of the irradiation light; and the irradiation unit includes a light adjustment unit that adjusts the light intensities of the irradiation light that irradiates the plurality of treatment liquid flow paths to be different from one another; The light adjusting unit adjusts the amount of light of the irradiation light irradiated onto one of the plurality of processing liquid flow paths so that the intensity of a haze noise component that varies depending on the intensity of the irradiation light approaches the intensity of a steady noise component that is generated regardless of the intensity of the irradiation light, among noise components contained in the light received by the light receiving unit when the irradiation light is irradiated onto the one of the plurality of processing liquid flow paths, under the condition that the intensity of the haze noise component that varies depending on the intensity of the irradiation light does not fall below the intensity of the steady noise component.

2. the irradiation unit is capable of irradiating the irradiation light toward each of the plurality of treatment liquid flow paths by moving relatively to the plurality of treatment liquid flow paths; The foreign matter detecting device according to claim 1 , wherein the light adjusting unit is provided on an optical path leading to each of the plurality of processing liquid flow paths.

3. a control unit that acquires an electrical signal corresponding to the intensity of the light received by the light receiving unit; the control unit estimates an intensity of the steady noise component and an intensity of the haze noise component based on an electrical signal corresponding to light received by the light receiving unit when the irradiation light is irradiated onto the one processing liquid flow path; 3. The foreign matter detection device according to claim 1, wherein the light adjusting unit adjusts the amount of the irradiation light irradiated onto the one processing liquid flow path based on the estimation result of the control unit so as to bring the intensity of a haze noise component that varies depending on the intensity of the irradiation light closer to the intensity of the steady noise component.

4. 4. The foreign matter detection device according to claim 3, wherein the control unit estimates the intensity of the steady noise component and the intensity of the haze noise component from an electrical signal corresponding to light received by the light receiving unit when different amounts of irradiation light are irradiated onto the one processing liquid flow path.

5. A foreign matter detection device configured to detect foreign matter contained in a processing liquid for substrate processing, comprising: an irradiation unit configured to irradiate irradiation light from a light source toward a treatment liquid flow path through which the treatment liquid supplied to the substrate flows; a light receiving unit configured to receive light emitted from the treatment liquid flow path by the irradiation of the irradiation light; and the irradiation unit includes a light adjustment unit that adjusts the amount of the irradiation light, The light adjusting unit adjusts the amount of light of the irradiation light irradiated onto the processing liquid flow path so that the intensity of a haze noise component that varies depending on the intensity of the irradiation light approaches the intensity of a steady noise component that occurs regardless of the intensity of the irradiation light, among noise components contained in the light received by the light receiving unit when the irradiation light is irradiated onto the processing liquid flow path, under the condition that the intensity of the haze noise component that varies depending on the intensity of the irradiation light does not fall below the intensity of the steady noise component.

6. The light receiving device further includes a control unit that acquires an electrical signal corresponding to the intensity of the light received by the light receiving unit, the control unit estimates the intensity of the steady noise component and the intensity of the haze noise component based on an electrical signal corresponding to light received by the light receiving unit when the irradiation light is irradiated onto the treatment liquid flow path; 6. The foreign matter detection device according to claim 5, wherein the light adjusting unit adjusts the amount of the irradiation light irradiated onto the processing liquid flow path based on the estimation result in the control unit so as to bring the intensity of a haze noise component that varies depending on the intensity of the irradiation light closer to the intensity of the steady noise component.

7. The foreign object detection device described in Claim 6, wherein the control unit estimates the intensity of the steady noise component and the intensity of the haze noise component from an electrical signal corresponding to the light received by the light receiving unit when different amounts of irradiation light are irradiated onto the treatment liquid flow path.

8. The irradiation unit is configured to be able to individually irradiate the irradiation light toward each of a plurality of treatment liquid flow paths, and has a plurality of light adjustment units respectively corresponding to the plurality of treatment liquid flow paths, 8. The foreign matter detection device according to claim 5, wherein each of the plurality of light adjusting units adjusts the amount of light of the irradiation light irradiated onto the corresponding processing liquid flow path so as to bring the intensity of the haze noise component closer to the intensity of the steady noise component.

9. 1. A foreign matter detection method for a foreign matter detection apparatus configured to detect foreign matters contained in a processing liquid for substrate processing, comprising: irradiating, by an irradiation unit, irradiation light from a light source toward a plurality of treatment liquid flow paths through which the treatment liquid to be supplied to the substrate flows; receiving light emitted from the treatment liquid flow path by the irradiation of the irradiation light with a light receiving unit; Including, The irradiation of the irradiation light includes a light adjusting unit for adjusting the light intensity of the irradiation light irradiating the plurality of treatment liquid flow paths to be different from one another; adjusting, by the light adjusting unit, the amount of the irradiation light irradiated onto one of the processing liquid flow paths, so that the intensity of a haze noise component that varies depending on the intensity of the irradiation light approaches the intensity of a stationary noise component that is generated regardless of the intensity of the irradiation light, among noise components contained in the light received by the light receiving unit when the irradiation light is irradiated onto the one of the multiple processing liquid flow paths; Including, Foreign object detection methods.

10. The irradiation unit is moved relatively to the plurality of treatment liquid flow paths, thereby irradiating the irradiation light toward each of the plurality of treatment liquid flow paths. The foreign object detection method according to claim 9.

11. Estimating the intensity of the stationary noise component and the intensity of the haze noise component based on an electrical signal corresponding to the light received by the light receiving unit when the irradiation light is irradiated onto the one processing liquid flow path; The foreign object detection method of claim 9 further comprising:

12. A foreign matter detection method as described in Claim 11, in which the intensity of the steady noise component and the intensity of the haze noise component are estimated from an electrical signal corresponding to the light received at the light receiving unit when different amounts of irradiation light are irradiated onto the one processing liquid flow path.

13. A method for detecting foreign matter in a foreign matter detection device configured to detect foreign matter contained in a processing liquid for substrate processing, comprising: irradiating irradiation light from a light source toward a processing liquid flow path through which the processing liquid to be supplied to the substrate flows; receiving light emitted from the treatment liquid flow path by the irradiation of the irradiation light; adjusting the amount of the irradiation light irradiated onto the treatment liquid flow path so that the intensity of a haze noise component that varies depending on the intensity of the irradiation light approaches the intensity of a stationary noise component that is generated regardless of the intensity of the irradiation light, among noise components contained in light received when the irradiation light is irradiated onto the treatment liquid flow path, under the condition that the intensity of the haze noise component does not fall below the intensity of the stationary noise component that is generated regardless of the intensity of the irradiation light; Including, Foreign object detection methods.

14. Estimating the intensity of the stationary noise component and the intensity of the haze noise component based on an electrical signal corresponding to light received when the irradiation light is irradiated onto the treatment liquid flow path; The foreign object detection method of claim 13 further comprising:

15. A foreign matter detection method as described in Claim 14, in which the intensity of the steady noise component and the intensity of the haze noise component are estimated from an electrical signal corresponding to the light received when different amounts of irradiation light are irradiated onto the processing liquid flow path.

16. The irradiation light is individually irradiated toward each of a plurality of treatment liquid flow paths, The foreign matter detection method according to any one of claims 13 to 15, wherein the light amount of the irradiation light irradiated onto each of the plurality of treatment liquid flow paths is individually adjusted so that the intensity of the haze noise component approaches the intensity of the steady noise component.

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