Foreign matter detection device and foreign matter detection method

Abstract

This invention relates to a foreign matter detection device and method, which efficiently detects foreign matter based on the state of the target liquid. The foreign matter detection device of this invention is used to detect foreign matter contained in a processing liquid used for substrate processing. The device includes: a processing liquid flow path forming section, forming a processing liquid flow path through which the processing liquid supplied to the substrate flows; an irradiation section, irradiating the processing liquid flow path with irradiation light from a light source; and a light receiving section, receiving light emitted from the processing liquid flow path by irradiation with the irradiation light. The irradiation section includes a light adjustment section that differentiates the light intensity of the irradiation light irradiating a plurality of processing liquid flow paths.

Description

Technical Field

[0001] This invention relates to a foreign object detection device and a foreign object detection method. Prior Technology

[0002] Patent Document 1 discloses a method for a substrate processing apparatus that optically detects foreign objects in a supply path through which a fluid supplied to a substrate flows. The apparatus projects light onto a flow path forming section through which the fluid flows, and as a result, receives the light generated from the flow path forming section and detects the foreign objects by its intensity. [Known Technical Documents] [Patent Literature]

[0003] Patent Document 1: Japanese Patent Application Publication No. 2020-119996 Summary of the Invention

[0004] [The problem that this invention aims to solve]

[0005] This invention provides a technique that can efficiently detect foreign objects based on the state of the liquid in question. [Technical means to solve the problem]

[0006] The present invention provides a foreign matter detection device for detecting foreign matter contained in a processing liquid used for substrate processing. The device includes: a plurality of processing liquid flow path forming sections forming processing liquid flow paths through which the processing liquid supplied to the substrate flows; an irradiation section capable of individually irradiating each of the plurality of processing liquid flow paths with irradiation light from a light source; and a light receiving section receiving light emitted from the processing liquid flow paths by irradiation with the irradiation light; the irradiation section includes a light adjustment section that makes the amount of irradiation light irradiating the plurality of processing liquid flow paths different from each other. [Effects of the Invention]

[0007] According to the present invention, a technique is provided that can efficiently detect foreign objects based on the state of the liquid in question. Simple Explanation of the Diagram

[0008] Figure 1 is a perspective view illustrating an example of a substrate processing system. Figure 2 is a schematic diagram of an example of a coating and developing apparatus. Figure 3 is a schematic diagram of an example of a liquid handling unit. Figure 4 is a schematic diagram of an example of the liquid supply section of a liquid processing unit. Figure 5 is a side view illustrating an example of a foreign object detection unit. Figure 6 is a perspective view illustrating an example of a foreign object detection unit. Figure 7 is a side view illustrating an example of a foreign object detection unit. Figure 8 is a block diagram showing an example of the functional configuration of the control unit. Figure 9 is a chart showing an example of the signal intensity corresponding to the detected light. Figures 10(a) and 10(b) illustrate an example of the relationship between changes in light intensity and the detection light. Figure 11 is a block diagram showing an example of the hardware configuration of the control unit. Figure 12 is a flowchart showing an example of a foreign object detection method. Figure 13 is a flowchart illustrating an example of a method for adjusting light intensity used in foreign object detection. Figure 14 is a side view illustrating another example of a foreign object detection unit. Implementation

[0009] The following describes various exemplary implementations.

[0010] In one exemplary embodiment, a foreign matter detection device is provided. This foreign matter detection device, used to detect foreign matter contained in a processing liquid for substrate processing, includes: a plurality of processing liquid flow path forming sections forming processing liquid flow paths through which the processing liquid supplied to the substrate flows; an irradiation section capable of individually irradiating each of the plurality of processing liquid flow paths with irradiation light from a light source; and a light receiving section receiving light emitted from the processing liquid flow paths by irradiation with the irradiation light; the irradiation section includes a light adjustment section that makes the amount of irradiation light irradiating the plurality of processing liquid flow paths different from each other.

[0011] According to the aforementioned foreign object detection device, after the light emitted from the light source is adjusted in intensity by the light adjustment unit included in the irradiation unit, it irradiates the processing fluid flow path. At this time, depending on whether processing fluids with different characteristics are flowing through multiple processing fluid flow paths, or whether flow conditions such as flow rate / volume are different, the intensity of the light irradiating these multiple processing fluid flow paths can be adjusted. Therefore, efficient foreign object detection corresponding to the state of the processing fluid in each processing fluid flow path can be performed. Furthermore, when the target liquids in the multiple processing fluid flow paths are of the same type or have the same characteristics, the intensity of the light can also be adjusted, for example, to set multiple standards for foreign object detection or to monitor the level of noise.

[0012] Alternatively, it can be configured as follows: the irradiation unit can irradiate the plurality of processing liquid flow paths with irradiation light by moving relative to them; the light adjustment unit is provided on the light path leading to each of the plurality of processing liquid flow paths. In this case, the light intensity of each processing liquid flow path can be adjusted individually, thus allowing for flexible adjustment of the light intensity.

[0013] Alternatively, the light adjustment unit adjusts the amount of illumination light illuminating one of the plurality of processing fluid flow paths to a condition not lower than the intensity of the normal noise component (which is independent of the intensity of the illumination light) in the light received by the light receiving unit when the illumination light is illuminating one of the processing fluid flow paths. This adjusts the intensity of the turbid noise component, which varies with the intensity of the illumination light, to be close to the intensity of the normal noise. The turbid noise component in the noise component of the light received by the light receiving unit is a component that varies with the intensity of the emitted light. Therefore, by adjusting the intensity of the illumination light to be close to the intensity of the normal noise component, the reduction in the accuracy of foreign object detection can be prevented, and the intensity of the illumination light can be reduced. []

[0014] Alternatively, it can be configured as follows: It 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 normal noise component and the intensity of the turbid noise component based on the electrical signal corresponding to the light received by the light receiving unit when the irradiation light is applied to a processing fluid flow path; the light adjustment unit adjusts the amount of irradiation light applied to the processing fluid flow path based on the estimation result of the control unit, so that the intensity of the turbid noise component, which varies with the intensity of the irradiation light, is close to the intensity of the normal noise. By adopting the above configuration, the intensity of the normal noise component and the intensity of the turbid noise component are estimated based on the electrical signal corresponding to the light received by the light receiving unit, and the amount of irradiation light is adjusted accordingly. Therefore, the intensity of the irradiation light can be adjusted with greater precision.

[0015] Alternatively, the control unit can determine the intensity of the normal noise component and the intensity of the turbid noise component based on the electrical signal corresponding to the light received by the light receiving unit when the light intensity is different from that of the light irradiating the processing fluid flow path. The intensity of the turbid noise component may vary depending on the intensity of the irradiated light. Therefore, by configuring it as described above to determine the intensity of the normal noise component and the turbid noise component based on the difference in light received by the light receiving unit when the irradiation light intensity is different, the relationship between the turbid noise component and the normal noise component can be determined more accurately.

[0016] In another exemplary embodiment, a foreign matter detection method is provided. This foreign matter detection method is a foreign matter inspection method within a foreign matter detection apparatus for detecting foreign matter contained in a processing liquid used for substrate processing. It includes the following steps: irradiating a plurality of processing liquid flow paths supplied to the substrate with irradiation light from a light source using an irradiation unit; and receiving light emitted from the processing liquid flow paths by the irradiation light using a light receiving unit; the irradiation unit, through a light adjustment unit, makes the intensity of the irradiation light irradiating the plurality of processing liquid flow paths different from each other.

[0017] According to the above-described foreign object detection method, after the light emitted from the light source is adjusted by the light adjustment unit included in the irradiation unit, it is used to irradiate the processing fluid flow path. At this time, in cases where processing fluids with different characteristics are flowing in multiple processing fluid flow paths, or where flow conditions such as flow rate / flow rate are different, the light intensity irradiated to these multiple processing fluid flow paths can be adjusted, thus enabling efficient foreign object detection that corresponds to the state of the processing fluid in each processing fluid flow path.

[0018] The following description refers to one embodiment. In this description, the same symbols are used for the same elements or elements with the same function, and repeated descriptions are omitted. A portion of the diagram shows an orthogonal coordinate system defined by the X-axis, Y-axis, and Z-axis. In the following embodiment, the Z-axis corresponds to the vertical direction, and the X-axis and Y-axis correspond to the horizontal direction.

[0019] [Substrate Processing System] The substrate processing system 1 (substrate processing apparatus) shown in Figure 1 is a system for forming a photosensitive film, exposing the photosensitive film, and developing the photosensitive film on a workpiece W. The workpiece W, the object of processing, is, for example, a substrate, or a substrate that has been formed with a film or circuit through predetermined processing. For example, the substrate included in the workpiece W is a silicon-containing wafer. The workpiece W (substrate) may also be circular. The workpiece W, the object of processing, may also be a glass substrate, a mask substrate, an FPD (Flat Panel Display), or an intermediate obtained by performing predetermined processing on such substrates. The photosensitive film is, for example, a photoresist film.

[0020] The substrate processing system 1 includes a coating and developing apparatus 2 and an exposure apparatus 3. The exposure apparatus 3 is used to expose a photoresist film (photosensitive film) formed on a workpiece W (substrate). Specifically, the exposure apparatus 3 irradiates the exposed portion of the photoresist film with energy lines using methods such as immersion exposure. The coating and developing apparatus 2 performs a process of coating the surface of the workpiece W with a photoresist (solution) to form a photoresist film before the exposure process performed by the exposure apparatus 3; and performs a development process on the photoresist film after the exposure process.

[0021] (Substrate processing apparatus) The following describes the configuration of the 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.

[0022] Carrier block 4 is used for the introduction of workpiece W into the coating and developing apparatus 2 and the removal of workpiece W from the coating and developing apparatus 2. For example, carrier block 4 can support multiple carriers C for workpiece W, and has a built-in transport device A1 including a transfer arm. Carrier C, for example, holds multiple circular workpieces W. Transport device A1 removes workpiece W from carrier C and transfers it to processing block 5, and receives workpiece W from processing block 5 and returns it to carrier C. Processing block 5 has multiple processing modules 11, 12, 13, and 14.

[0023] Processing module 11 includes a liquid processing unit U1, a heat treatment unit U2, and a transport device A3 for moving workpiece W to these units. Processing module 11 forms a lower film on the surface of workpiece W using the liquid processing unit U1 and the heat treatment unit U2. The liquid processing unit U1 applies a processing liquid for lower film formation to the workpiece W. The heat treatment unit U2 performs various heat treatments accompanying the formation of the lower film.

[0024] The processing module 12 includes a liquid processing unit U1, a heat treatment unit U2, and a transport device A3 for moving workpiece W between these units. The processing module 12 forms a photoresist film on a lower film using the liquid processing unit U1 and the heat treatment unit U2. The liquid processing unit U1 applies a processing liquid (photoresist) for photoresist film formation to the lower film. The heat treatment unit U2 performs various heat treatments associated with the formation of the photoresist film.

[0025] The processing module 13 includes a liquid processing unit U1, a heat treatment unit U2, and a transport device A3 for moving workpiece W between these units. The processing module 13 forms an upper layer film on the photoresist film using the liquid processing unit U1 and the heat treatment unit U2. The liquid processing unit U1 applies a liquid for upper layer film formation onto the photoresist film. The heat treatment unit U2 performs various heat treatments accompanying the formation of the upper layer film.

[0026] Processing module 14 includes a liquid processing unit U1, a heat treatment unit U2, and a transport device A3 for moving workpiece W to these units. Processing module 14, through the liquid processing unit U1 and the heat treatment unit U2, performs the development process of the photoresist film that has undergone exposure treatment, and the accompanying heat treatment. The liquid processing unit U1 applies a developing solution to the surface of the exposed workpiece W, then washes it off with a rinsing solution, thereby performing the development process of the photoresist film. The heat treatment unit U2 performs various heat treatments accompanying the development process. Specific examples of heat treatment include pre-development heat treatment (PEB: Post Exposure Bake) and post-development heat treatment (PB: Post Bake).

[0027] A shelving unit U10 is installed on the side of the carrier block 4 within processing block 5. The shelving unit U10 is divided into multiple small units arranged side by side in the vertical direction. A conveying device A7, including a lifting arm, is installed near the shelving unit U10. The conveying device A7 causes the workpiece W to move up and down between the small units of the shelving unit U10.

[0028] A shelving unit U11 is provided on the side of the interface block 6 within the processing block 5. The shelving unit U11 is divided into a plurality of small units arranged side by side in the vertical direction.

[0029] Interface block 6 performs the transfer of workpiece W between itself and exposure device 3. For example, interface block 6, connected to exposure device 3, has a built-in transport device A8 containing a transfer arm. Transport device A8 transfers workpiece W, which is positioned in shelf unit U11, to exposure device 3. Transport device A8 receives workpiece W from exposure device 3 and returns it to shelf unit U11.

[0030] The control device 18, for example, controls the coating and developing device 2 to perform the coating and developing process in the following sequence. First, the control device 18 controls the transport device A1 to transport the workpieces W in the carrier C to the shelf unit U10, and controls the transport device A7 to arrange these workpieces W in the small unit for the processing module 11.

[0031] Next, the control device 18 controls the transport device A3 to transport the workpiece W from the shelf unit U10 to the liquid treatment unit U1 and the heat treatment unit U2 within the processing module 11. Furthermore, the control device 18 controls the liquid treatment unit U1 and the heat treatment unit U2 to form a lower film on the surface of these workpieces W. Then, the control device 18 controls the transport device A3 to return the workpiece W with the lower film formed to the shelf unit U10, and controls the transport device A7 to place these workpieces W into a small unit for use in the processing module 12.

[0032] Next, the control device 18 controls the transport device A3 to transport the workpiece W from the shelf unit U10 to the liquid treatment unit U1 and the heat treatment unit U2 within the processing module 12. Furthermore, the control device 18 controls the liquid treatment unit U1 and the heat treatment unit U2 to form a photoresist film on the surface of these workpieces W. Then, 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 these workpieces W into a small unit for use in the processing module 13.

[0033] Next, the control device 18 controls the transport device A3 to transport the workpiece W from the shelf unit U10 to the various units within the processing module 13. Furthermore, the control device 18 controls the liquid processing unit U1 and the heat treatment unit U2 to form an upper film on the photoresist film of these workpieces W. Then, the control device 18 controls the transport device A3 to transport the workpiece W to the shelf unit U11.

[0034] Next, the control device 18 controls the transport device A8 to send the workpiece W from the shelf unit U11 to the exposure device 3. Then, the control device 18 controls the transport device A8 to take the exposed workpiece W from the exposure device 3 into the small unit of the processing module 14 in the shelf unit U11.

[0035] Next, control device 18 controls transport device A3 to transport workpieces W from shelf unit U11 to various units within processing module 14, and controls liquid treatment unit U1 and heat treatment unit U2 to perform development processing on the photoresist film of these workpieces W. Then, control device 18 controls transport device A3 to return workpieces W to shelf unit U10, and controls transport devices A7 and A1 to return these workpieces W to carrier C. Through the above methods, the coating and development process is completed.

[0036] (Liquid processing unit) Next, referring to Figures 3 and 4, an example of the liquid processing unit U1 will be described in detail. Here, the liquid processing unit U1 (processing liquid supply unit) in the processing module 12 that forms the photoresist film will be described as an example. As shown in Figure 3, the liquid processing unit U1 includes a rotating holding part 20 and a processing liquid supply part 30.

[0037] The rotating holding part 20, according to the operation instruction of the control device 18, holds the workpiece W and rotates it. The rotating holding part 20, for example, includes a holding part 22 and a rotating drive part 24. The holding part 22 supports the center portion of the horizontally positioned workpiece W with its front side Wa facing upwards, and holds the workpiece W, for example, by vacuum suction. The rotating drive part 24, for example, is an actuator containing a power source such as an electric motor, that rotates the holding part 22 about a vertical axis Ax. This causes the workpiece W on the holding part 22 to rotate.

[0038] The processing liquid supply unit 30, according to the operation instruction of the control device 18, sprays processing liquid onto the front surface Wa of the workpiece W, thereby supplying processing liquid to the front surface Wa. The processing liquid supplied by the processing liquid supply unit 30 is a substrate processing solution used for processing the workpiece W. Examples of processing liquids include solutions (photoresist) used for forming photoresist films and solutions (e.g., diluents) used for pre-wetting treatment to improve the wettability of the front surface Wa to the photoresist. The processing liquid supply unit 30, for example, includes a plurality of nozzles 32, a holding head 34, and a supply unit 36.

[0039] A plurality of nozzles 32 each spray treatment fluid onto the front surface Wa of the workpiece W held by the holding part 22. The plurality of nozzles 32 are positioned above the workpiece W, for example, while held in place by the holding head 34, and individually spray treatment fluid downwards. The holding head 34 can also be moved along the front surface Wa of the workpiece W by a drive unit (not shown). The number of nozzles 32 is not limited, but the following description will use the case where the treatment fluid supply unit 30 has 12 nozzles 32 (hereinafter referred to as "nozzles 32A~32L") as an example.

[0040] Processing liquid is supplied to nozzles 32A to 32L from the supply unit 36. Alternatively, different types of processing liquid can be supplied to nozzles 32A to 32L from the supply unit 36. As an example, different types of photoresist are supplied to nozzles 32A to 32J from the supply unit 36, and different types of diluent are supplied to nozzles 32K and 32L from the supply unit 36.

[0041] As shown in Figure 4, the supply unit 36 ​​includes a plurality of supply pipes 42A-42L and a plurality of supply sources 44A-44L. Supply pipe 42A forms a flow path between the liquid source (supply source 44A) that supplies (ejects from nozzle 32A) the treatment liquid to nozzle 32A and nozzle 32A. Supply source 44A may include, for example, a bottle storing the treatment liquid and a pump that pressurizes the treatment liquid from the bottle to nozzle 32A. Similarly, supply pipes 42B-42L also form flow paths between the liquid sources (supply sources 44B-44L) and nozzles 32B-32L, respectively.

[0042] The supply unit 36 ​​further includes multiple on / off valves V, each installed in a plurality of supply pipes 42A-42L. The on / off valves V are switched to an open or closed state according to the operation instruction of the control device 18. By switching the open / off states of the multiple on / off valves V, the flow paths of the supply pipes 42A-42L are opened and closed respectively. For example, if the on / off valve V is in the open state, the treatment fluid flows within the flow paths of the supply pipes 42A-42L and is sprayed from the nozzles 32A-32L onto the front surface Wa of the workpiece W.

[0043] (Foreign Object Detection Unit) The coating and developing apparatus 2 is further equipped with a foreign matter detection unit 50 (foreign matter detection device) for detecting 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 the processing liquid flowing through the flow paths of a plurality of supply pipes 42A-42L. The foreign matter detection unit 50 may be disposed near the liquid processing unit U1 or within the housing of the liquid processing unit U1. A portion of the elements of the foreign matter detection unit 50 may also be disposed between the on / off valve V and the nozzles 32A-32L in the flow paths of the supply pipes 42A-42L. In the following description, an example of the foreign matter detection unit 50 will also be explained with reference to Figures 5-11.

[0044] The foreign object detection unit 50 forms a flow path (hereinafter referred to as "processing fluid flow path") through which the processing fluid flowing in the supply pipes 42A to 42L flows. The foreign object detection unit 50 receives light generated in the processing fluid flow path by irradiating the processing fluid flow path with irradiation light (e.g., laser light), thereby detecting foreign objects in the processing fluid flowing in the processing fluid flow path. As shown in FIG5, the foreign object detection unit 50 includes, for example, a housing 52, a flow path forming part 60, and a measuring part 70. The housing 52 includes an upper wall 54a, a bottom wall 54b, and side walls 56a to 56d. As an example, the upper wall 54a and the bottom wall 54b are arranged horizontally (along the XY plane). In addition, the side walls 56a and 56b are arranged vertically along the Y-axis direction (along the YZ plane) and face each other in the X-axis direction (first direction). Furthermore, sidewalls 56c and 56d are respectively arranged perpendicularly along the X-axis direction (along the XZ plane) and facing each other in the Y-axis direction (second direction). The housing 52 houses the flow path forming section 60 and the measuring section 70.

[0045] The flow path forming section 60 forms a plurality of processing fluid flow paths respectively disposed on the flow paths of the supply pipes 42A to 42L. Each of the plurality of processing fluid flow paths formed by the flow path forming section 60 is used to detect foreign matter contained in the processing fluid flowing through that flow path. For example, as shown in FIG. 6, the flow path forming section 60 includes a plurality of processing fluid flow path forming sections 62A to 62L. The plurality of processing fluid flow path forming sections 62A to 62L are configured identically to each other. In the following description, the details of the processing fluid flow path forming section will be explained using processing fluid flow path forming section 62A as an example.

[0046] As shown in Figure 5, the processing fluid flow path forming section 62A forms a processing fluid flow path 64 in the flow path of the supply pipe 42A that connects the supply source 44A and the nozzle 32A (also refer to Figure 4). The upstream and downstream ends of the processing fluid flow path 64 are connected to the supply pipe 42A. Thereby, the processing fluid pressurized from the supply source 44A passes sequentially through a portion of the flow path of the supply pipe 42A, the processing fluid flow path 64 of the processing fluid flow path forming section 62A, and the remaining portion of the flow path of the supply pipe 42A, and is sprayed from the nozzle 32A onto the front surface Wa of the workpiece W.

[0047] The processing fluid flow path forming section 62A includes, for example, a block body 66 in which a processing fluid flow path 64 is formed internally. The block body 66 is made of a material that is transmissible to laser light used during foreign object detection. Examples of materials constituting the block body 66 include quartz and sapphire. The block body 66 may be formed in a cuboid shape, with one side of the block body 66 facing the sidewall 56a. As an example, the inlet 64a and outlet 64b of the processing fluid flow path 64 are formed on the side of the block body 66 facing the sidewall 56a. The inlet 64a may also be located below the outlet 64b.

[0048] The processing fluid 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 in the illustration) along the bottom wall 54b. One end of the first flow path 68a near the side wall 56a forms an inlet 64a, and the other end of the first flow path 68a near the side wall 56b connects 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). One end of the second flow path 68b near the bottom wall 54b connects to the first flow path 68a, and the other end of the second flow path 68b near the top wall 54a connects to the third flow path 68c. The third flow path 68c is formed to extend horizontally (along the X-axis) along the bottom wall 54b. One end of the third flow path 68c near the sidewall 56b is connected to the second flow path 68b, and the other end of the third flow path 68c near the sidewall 56a forms the outlet 64b.

[0049] At the inlet 64a, a supply pipe (hereinafter referred to as "upstream supply pipe 46") is connected to the supply pipe 42A, which is upstream of the processing fluid flow path forming section 62A. At the outlet 64b, a supply pipe (hereinafter referred to as "downstream supply pipe 48") is connected to the supply pipe 42A, which is downstream of the processing fluid flow path forming section 62A. The upstream supply pipe 46 and the downstream supply pipe 48 penetrate the side wall 56a opposite to the block body 66. With the above configuration, the processing fluid delivered from the supply source 44A passes sequentially through the upstream supply pipe 46, the first flow path 68a, the second flow path 68b, the third flow path 68c, and the downstream supply pipe 48, and is supplied to the workpiece W from the nozzle 32A.

[0050] As described above, the processing fluid flow path forming sections 62A-62L shown in FIG. 6 are constructed identically to each other. Therefore, like processing fluid flow path forming section 62A, each of the processing fluid flow path forming sections 62B-62L includes a block body 66 with a processing fluid flow path 64 internally formed. Each of the processing fluid flow path forming sections 62B-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-42L are connected to the inlet 64a (first flow path 68a) of the processing fluid flow path forming sections 62B-62L, respectively. The downstream supply pipes 48 of the supply pipes 42B-42L are connected to the outlet 64b (third flow path 68c) of the processing fluid flow path forming sections 62B-62L, respectively.

[0051] The processing fluid flow path forming units 62A-62L are arranged side-by-side along the direction from side wall 56d to side wall 56c (along the Y-axis direction), each facing the side wall 56a. The processing fluid flow path forming units 62A-62L can also be arranged in the aforementioned order with intervals between them. The height position (position in the Z-axis direction) of the first flow path 68a of the processing fluid flow path forming units 62A-62L can also be slightly consistent with each other.

[0052] The distance (position in the X-axis direction) of the second flow path 68b of the processing fluid flow path forming sections 62A to 62L from the side wall 56a can also be slightly consistent with each other. In addition, the height position (distance from the bottom wall 54b) of the third flow path 68c of the processing fluid flow path forming sections 62A to 62L can also be slightly consistent with each other.

[0053] The first flow path 68a of the processing fluid flow path forming sections 62A to 62L is arranged side by side along the Y-axis direction. The second flow path 68b of the processing fluid flow path forming sections 62A to 62L is arranged side by side along the Y-axis direction. The third flow path 68c of the processing fluid flow path forming sections 62A to 62L is arranged side by side along the Y-axis direction.

[0054] Returning to Figure 5, the measuring unit 70 includes a light source 72, an irradiation unit 74, a light receiving unit 76, a holding unit 78, and a driving unit 80. The light source 72 generates laser light as irradiation light for detecting foreign matter in the processing liquid. The light source 72, for example, emits laser light with a wavelength of 400nm to 1000nm and an output of 600mW to 1000mW. The light source 72, for example, as shown in Figure 7, is disposed on the bottom wall 54b, positioned lower than the processing liquid flow path forming sections 62A to 62L. As an example, the light source 72 emits laser light in the direction from the side wall 56d to the side wall 56c (negative Y-axis direction). The light source 72 is positioned in the Y-axis direction at a different position than the processing liquid flow path forming section 62A. The light source 72 is disposed separately from the processing liquid flow path forming section 62A in the Y-axis direction.

[0055] The irradiation unit 74 irradiates the processing fluid flow paths 64 of the processing fluid flow path forming units 62A-62L with irradiation light from the light source 72. The irradiation unit 74 is configured, for example, to irradiate the processing fluid flow paths 64 of the processing fluid flow path forming units 62A-62L individually with irradiation light. The irradiation unit 74 may also be disposed below the processing fluid flow path 64. The irradiation unit 74 may, for example, include an optical component 82, which irradiates the processing fluid flow paths 64 with irradiation light by changing the direction of the irradiation light from the light source 72.

[0056] The optical component 82 includes, for example, a reflective component 82a, a condenser lens 82b, a neutral density filter 82c, and a collecting portion 82d. The reflective surface of the reflective component 82a faces the light source 72 in the Y-axis direction. The reflective surface of the reflective component 82a reflects the illumination light emitted slightly horizontally from the light source 72 upwards. The condenser lens 82b is positioned above the reflective component 82a to focus the illumination light reflected by the reflective component 82a onto a measurement position set in the processing fluid flow path 64. The condenser lens 82b is configured, for example, to illuminate the measurement position of the first flow path 68a set in the processing fluid flow path 64. Furthermore, the focusing position generated by the condenser lens 82b can also be set considering the possibility that the path of the illumination light can be changed by the neutral density filter 82c, which will be described later.

[0057] The neutral density filter 82c functions as a light-reducing component, reducing the light emitted from the condenser lens 82b and directing it towards the processing liquid flow path 64. In other words, the neutral density filter 82c acts as a light adjustment unit to adjust the amount of light emitted towards the processing liquid flow path 64. For example, a neutral density (ND) filter can be used as the neutral density filter 82c. In this embodiment, a reflective ND filter is shown as the neutral density filter 82c. In the case of a reflective ND filter, a predetermined proportion of the incident light is transmitted through the ND filter and emitted towards the processing liquid flow path 64, while a portion of the light is reflected by the filter. A collecting unit 82d is provided on the light path of the light reflected from the neutral density filter 82c. A beam trap that absorbs the irradiated light can be used as the collecting unit 82d. For example, a beam splitter can be used as the reflective ND filter.

[0058] As shown in FIG7, the neutral density filter 82c can also be individually provided for the processing fluid flow path 64 of each of the processing fluid flow path forming sections 62A to 62L. As shown in FIG5, the plurality of neutral density filters 82c can also be configured such that the sidewall 56a is fixed by the support member 82e.

[0059] Furthermore, the degree to which the light reduction filter 82c reduces the illumination light (reduction rate) can be varied, for example, depending on the characteristics of the processing fluid flowing through the processing fluid flow path 64. When adjusting the reduction rate of the light reduction filter 82c, for instance, it can be set to reduce the amount of illumination light emitted from the light reduction filter 82c into the processing fluid flow path 64 within a range that does not reduce the detection performance of foreign objects. Details will be elaborated later.

[0060] Furthermore, while the above description pertains to the case where the neutral density filter 82c is a neutral density filter, neutral density filters 82c with different optical properties for light reduction can also be used. For example, a filter having the optical property of selectively reducing light within a specific wavelength range can also be used as the neutral density filter 82c. Regarding the selection of filter optical properties, for example, it can be varied within a range that allows the light receiving unit 76 to sufficiently detect the presence of foreign matter mixed into the processing liquid.

[0061] When each of the processing fluid flow paths 64 in the processing fluid flow path forming sections 62A to 62L is individually equipped with a neutral density filter 82c, the neutral density filters 82c may be configured to have different neutral density ratios. When the same type of processing fluid flows through each of the processing fluid flow paths 64 in the processing fluid flow path forming sections 62A to 62L, the neutral density filters 82c corresponding to each processing fluid flow path 64 may have the same neutral density ratio. On the other hand, when the types of processing fluids flowing through the processing fluid flow paths 64 are different, a neutral density filter 82c having a neutral density ratio corresponding to the type of processing fluid may be provided.

[0062] Furthermore, if each of the processing fluid flow paths 64 of the processing fluid flow path forming sections 62A to 62L is individually provided with an attenuation filter 82c, the optical characteristics of the multiple attenuation filters 82c can be configured such that their attenuation rates differ from each other. Optical characteristics other than attenuation rate can be, for example, polarization characteristics. In addition, the configuration can also utilize filters with attenuation characteristics corresponding to different wavelengths.

[0063] The holding part 78 movably holds all components of the optical component 82 except for the light-reducing filter 82c (reflecting component 82a, condensing lens 82b, and collecting part 82d). The holding part 78 may include, for example, a guide rail 88 and a slide 84. The guide rail 88 may also be provided on the bottom wall 54b and formed to extend along the direction from the side wall 56c to the side wall 56d (along the Y-axis direction). For example, as shown in FIG7, the guide rail 88 may also extend along the Y-axis direction at least between the processing fluid flow path forming parts 62A-62L. The guide rail 88 movably supports the slide 84.

[0064] The slide 84 is positioned below the processing fluid flow path forming sections 62A-62L and supports the optical component 82 (e.g., the reflective component 82a). The slide 84, as shown in FIG5 or FIG7, is formed to extend along a direction intersecting the guide rail 88 (e.g., the X-axis direction). For example, when viewed from the side, one end of the slide 84 near the side wall 56a is located below the processing fluid flow path forming section 62A, and the other end near the side wall 56b is located closer to the side wall 56b than the position of the processing fluid flow path forming section 62A. As an example, a component of the optical component 82 that holds the retaining section 78 is positioned at the end of the slide 84 near the side wall 56a.

[0065] The drive unit 80 uses a power source such as an electric motor to move the slide 84 along the guide rail 88. By moving the slide 84 along the guide rail 88, the illumination unit 74 (the component in the optical component 82 that is held in the holding unit 78) moves along the Y-axis direction.

[0066] The light receiving unit 76 receives light emitted from the processing liquid flow path 64 by irradiation from the irradiation unit 74. The light receiving unit 76 may also be configured to enclose the processing liquid flow path forming units 62A~62L between itself and the side wall 56a.

[0067] The light receiving section 76 includes, for example, an optical component 92 and a light receiving element 94. In the direction from sidewall 56a to sidewall 56b (X-axis direction), the processing fluid flow path forming section 62A, the optical component 92, and the light receiving element 94 are sequentially arranged. The height positions of the optical component 92 and the light receiving element 94 may, for example, be slightly consistent with the height position of the first flow path 68a of the processing fluid flow path 64.

[0068] Optical component 92, for example, includes a focusing lens that focuses light emitted from the processing liquid flow path 64 toward light receiving element 94. A wavelength filter that allows only light of a specific wavelength to pass through may also be provided inside optical component 92. Light receiving element 94 receives the light focused by optical component 92 and generates an electrical signal corresponding to the received light (detection light). Light receiving element 94, for example, includes a photodiode that performs photoelectric conversion.

[0069] Optical component 92 and light receiving element 94 are mounted on a support member 86 extending vertically. The support member 86 is connected to a slide 84. For example, the lower end of the support member 86 is connected to the end of the slide 84 opposite to the end where the optical component 82 is mounted. Accompanying the movement of the slide 84 by the drive unit 80, the optical component 92 and light receiving element 94 move along the Y-axis.

[0070] With the above configuration, the drive unit 80 moves the irradiation unit 74 (the optical component 82 held in the holding unit 78) and the light receiving unit 76 together along the Y-axis by moving the slide 84. The drive unit 80, for example, moves the irradiation unit 74 and the light receiving unit 76 between positions where the irradiation unit 74 and the light receiving unit 76 are respectively opposite to the processing liquid flow path forming unit 62A, and between positions where the irradiation unit 74 and the light receiving unit 76 are respectively opposite to the processing liquid flow path forming unit 62L. In the following description, the position where the irradiation unit 74 and the light receiving unit 76 are respectively opposite to any processing liquid flow path forming unit will be referred to as the position corresponding to that processing liquid flow path forming unit.

[0071] As an example, while the irradiation light from the light source 72 onto the optical component 82 is continuous, the driving unit 80 moves the optical component 82 to below any one of the processing liquid flow paths 64 of the processing liquid flow path forming units 62A-62L, thereby irradiating the processing liquid flow path 64 with irradiation light from the irradiation unit 74. The irradiation light irradiating the processing liquid flow path 64 is light that has been reduced by a light-reducing filter 82c disposed below the processing liquid flow path 64. When irradiating with irradiation light, the light receiving element 94 receives the light emitted from the processing liquid flow path 64.

[0072] As described above, the irradiation unit 74 is positioned below the measurement position set in the processing liquid flow path 64, and the light receiving unit 76 is positioned to the side of the measurement position. Therefore, when irradiation light is applied to the processing liquid flow path 64, the light receiving unit 76 receives a portion of the light (scattered light) generated by the irradiation light being scattered at the measurement position within the processing liquid flow path 64. If irradiation light is applied to the processing liquid flow path 64 through which a solution such as a processing liquid flows, scattered light is generated due to the composition of the processing liquid, regardless of the presence or absence of foreign matter. When the solution does not contain foreign matter, most of the irradiation light passes through the processing liquid flow path 64. On the other hand, if the solution contains foreign matter, the degree of scattering of the irradiation light within the processing liquid flow path 64 increases, and the intensity of the light received by the light receiving unit 76 (a portion of the scattered light heading towards the light receiving unit 76) becomes greater compared to the case without foreign matter.

[0073] Additionally, as shown in Figure 7, the foreign object detection unit 50 may also include a heat sink 58. The heat sink 58 may also be disposed outside the housing 52. For example, the heat sink 58 may be disposed on the outer surface of the bottom wall 54b at a position corresponding to the light source 72. The heat sink 58 may also be a water-cooled heat sink. The heat sink 58 suppresses the temperature rise within the housing 52 originating from optical components such as the light source 72. This reduces the impact of heat generated by optical components such as the light source 72 on the processing fluid (substrate processing).

[0074] The foreign object detection unit 50 may also include a control unit 100. The control unit 100 controls various elements of the foreign object detection unit 50. The control unit 100 may be disposed, for example, inside the housing 52.

[0075] As shown in FIG8, the control unit 100, as a functional component (hereinafter referred to as "functional module"), includes, for example, a signal acquisition unit 102, a foreign object detection unit 104, a processing information acquisition unit 106, a drive control unit 108, and an output unit 110. Furthermore, the control unit 100 includes a noise evaluation unit 112 and a light intensity adjustment unit 114. Additionally, the processing performed by the signal acquisition unit 102, the foreign object detection 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 intensity adjustment unit 114 is equivalent to the processing performed by the control unit 100.

[0076] The signal acquisition unit 102 acquires an electrical signal corresponding to the intensity of the detection light from the light receiving unit 76. For example, the signal acquisition unit 102 acquires an electrical signal corresponding to the intensity of light emitted from the processing liquid flow path 64 (first flow path 68a) through which the processing liquid being monitored flows from the processing liquid flow path forming units 62A-62L. The signal acquisition unit 102, for example, acquires an electrical signal having an amplitude corresponding to the intensity of the detection light.

[0077] The foreign matter detection unit 104 detects the presence or absence of foreign matter in the processing fluid based on the amplitude and intensity (hereinafter referred to as "signal intensity") of the electrical signal corresponding to the detection light. Figure 9 schematically shows a graph illustrating an example of the time variation of the signal intensity obtained from the signal acquisition unit 102. For example, as shown in Figure 9, the foreign matter detection unit 104 determines that the processing fluid contains foreign matter when the signal intensity is greater than a predetermined threshold Th. The foreign matter detection unit 104 determines that the processing fluid does not contain foreign matter when the signal intensity is below the predetermined threshold Th. The threshold Th is a preset value that takes into account the intensity of scattered light when the irradiating light is scattered in the foreign matter in the processing fluid.

[0078] The noise evaluation unit 112 identifies the components of noise using an electrical signal corresponding to the intensity of the detection light. Furthermore, the light intensity adjustment unit 114 adjusts the amount of light irradiating the processing liquid based on the results of the noise component identification generated by the noise evaluation unit 112.

[0079] Referring to Figures 9 and 10, the adjustments made by the noise evaluation unit 112 and the light intensity adjustment unit 114 will be explained. As shown in Figure 9, the signal intensity obtained from the signal acquisition unit 102 includes not only those exceeding the threshold Th, but also noise components N that vary below the threshold Th. Noise components N may include machine noise and clouding noise. Machine noise is a fixed component originating from the electrical circuitry of the device, and may be of a certain intensity regardless of the intensity of light irradiating the processing fluid flow path 64. Therefore, in this embodiment, machine noise is sometimes referred to as normal noise.

[0080] On the other hand, turbidity noise arises from the composition of the processing fluid. As mentioned above, if illumination light is shone into the processing fluid flow path 64 through which the processing fluid or other solution flows, scattered light is generated due to the composition of the processing fluid, regardless of the presence or absence of foreign matter. When this scattered light originating from the components of the processing fluid is incident on the light receiving element 94, the electrical signal emitted from the light receiving element 94 is equivalent to turbidity noise. Since turbidity noise is not an electrical signal indicating the presence of foreign matter, a threshold Th can be set to determine the presence or absence of foreign matter, so that turbidity noise detection is not considered a result of foreign matter detection.

[0081] The scattered light emitted from the processing fluid flow path 64 by the illumination light applied to the foreign object, as well as the aforementioned turbidity noise, are all light generated by the illumination light. Therefore, their signal strength may change depending on the intensity of the illumination light. Figure 10 illustrates how the signal strength of each noise and the intensity of the electrical signal of the presence of the foreign object change when the intensity of the illumination light applied to the processing fluid flow path 64 is changed.

[0082] Figure 10(a) shows the states of the three signals PS1 to PS3 detected by light from the processing fluid flow path 64 when foreign objects are detected. Figure 10(a) also shows machine noise and turbid noise. The dashed line representing the level of machine noise and the solid line representing the level of turbid noise in Figure 10(a) show the noise levels that may be generated at those levels. In the example shown in Figure 10(a), the turbid noise level is larger than the machine noise level. Signal PS3 of the three signals PS1 to PS3 is masked by the turbid noise; therefore, signal PS3 is not actually identified as a signal originating from a foreign object in the foreign object detection unit 104, but may be identified as part of the noise. That is, in the example shown in Figure 10(a), only signals PS1 and PS2 may be identified as signals indicating the detection of a foreign object.

[0083] If the intensity of the illumination light illuminating the processing fluid flow path 64 is reduced, the intensity of signals PS1 to PS3 also decreases. Figure 10(b) shows how the intensity of the signals detected from the light from the processing fluid flow path 64 changes when the intensity of the illumination light is reduced. As can be seen by comparing Figures 10(a) and 10(b), if the intensity of the illumination light is reduced, the signals PS1 to PS3 and the turbidity noise level all decrease. However, since the intensity of the scattered light is proportional to the intensity of the illumination light, the intensity of each signal changes while maintaining a proportional relationship according to the change in the illumination light. Therefore, if the illumination light is weakened, as shown in Figure 10(b), the intensity of each signal decreases while slightly maintaining the intensity relationship between signals PS1 to PS3 and the turbidity noise level. Therefore, even if the intensity of the illumination light is reduced to the point where the levels of turbidity noise and machine noise are roughly equal, the signals PS1 and PS2 can still be distinguished from the noise components (turbidity noise and machine noise), thus maintaining detection accuracy.

[0084] On the other hand, if the intensity of the irradiation light is reduced to the point where the level of turbidity noise becomes smaller than the level of machine noise, there is a possibility that the signal PS2 may become mixed with noise components, potentially reducing the detection accuracy of foreign objects. Therefore, the minimum amount of irradiation light required to maintain detection accuracy is achieved by making the level of turbidity noise and the level of machine noise approximately equal. Then, the amount of light is adjusted using the aforementioned light-reducing filter 82c, etc., so that the processing fluid flow path 64 can be irradiated with irradiation light under these conditions.

[0085] The aforementioned noise evaluation unit 112 and light intensity adjustment unit 114 are capable of adjusting the light intensity irradiating the processing fluid flow path 64 using the aforementioned method. Specifically, the noise evaluation unit 112 is capable of identifying turbidity noise components and machine noise components from the measured signal intensity results. Furthermore, the light intensity adjustment unit 114 is capable of calculating the amount of irradiated light that can be reduced based on the components identified by the noise evaluation unit 112.

[0086] As a method for distinguishing between turbid noise components and machine noise components in the noise evaluation unit 112, examples include: measuring two results under different light intensity conditions while the same type of processing liquid is flowing through the same processing liquid flow path 64. As mentioned above, turbid noise components are components that may vary depending on the intensity of the irradiated light. Therefore, based on whether the noise component N changes with the light intensity, it can be identified whether the level of turbid noise in the noise component N is higher than the level of machine noise. Furthermore, the light intensity adjustment unit 114 can reduce the intensity of the irradiated light and repeat the measurement, identifying the state where the variation of noise component N decreases as the minimum intensity of the irradiated light. Additionally, a state where the light intensity is slightly increased from the minimum intensity can 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 identify the relationship between the turbid noise component and the machine noise component, and set the light intensity of the reduced irradiation light within the range that the machine noise component does not affect the detection accuracy of foreign objects.

[0087] It can also be configured to output the result of adjusting the light intensity generated by the noise evaluation unit 112 and the light intensity adjustment unit 114 from the output unit 110 to the control device 18. In addition, it can also be configured to control the drive control unit 108 to adjust the light intensity based on the result of adjusting the light intensity generated by the noise evaluation unit 112 and the light intensity adjustment unit 114.

[0088] The processing information acquisition unit 106 acquires processing information (hereinafter referred to as "processing information") performed in the liquid processing unit U1 from the control device 18. The processing information includes, for example, information displaying the nozzle (the monitored processing liquid) being sprayed in the liquid processing unit U1, and information displaying the start time and supply time of the processing liquid. The processing information acquisition unit 106 may also acquire processing information from the control device 18 for each processing using a particular processing liquid until the supply of that processing liquid begins.

[0089] The drive control unit 108 moves the irradiation unit 74 and the light receiving unit 76 between the processing fluid flow path forming units 62A-62L by moving the slide 84 via the drive unit 80. For example, based on the processing fluid indicated by the processing information, the drive control unit 108 moves the irradiation unit 74 and the light receiving unit 76 to a position corresponding to the processing fluid flow path 64 through which the processing fluid passes in the processing fluid flow path forming units 62A-62L. For example, when the processing fluid flow path 64 is not irradiated with light, the drive control unit 108 moves the irradiation unit 74 and the light receiving unit 76 to a predetermined standby position via the drive unit 80. In one example, the standby position may also be set to a position that does not overlap with the processing fluid flow path forming units 62A-62L.

[0090] The drive control unit 108 controls the drive unit 80 to irradiate the processing fluid flow path 64 with irradiation light during at least a portion of the period when processing fluid is supplied to the workpiece W. The drive control unit 108 also controls the drive unit 80 to irradiate a position different from the processing fluid flow path 64 of the processing fluid flow path forming units 62A-62L in a standby position during at least a portion of the period when no processing fluid is supplied to the workpiece W.

[0091] The output unit 110 outputs the determination result generated by the foreign object determination unit 104 to the outside of the foreign object detection unit 50. The output unit 110 can output the determination result to the control device 18, or to a display for reporting the result to the operator. For example, if the foreign object determination unit 104 determines that a foreign object is present, the output unit 110 can also output an alarm signal indicating that the monitored processing fluid contains a foreign object. Furthermore, the output unit 110 can also output the adjustment results of the light intensity generated by the noise evaluation unit 112 and the light intensity adjustment unit 114 to the control device 18.

[0092] The control unit 100 comprises one or more control computers. For example, the control unit 100 includes the circuit 200 shown in FIG. 11. The circuit 200 includes one or more processors 202, memory 204, storage 206, input / output ports 208, and timers 212. The storage 206 may be a recording medium, such as a hard disk, that can be read by a computer. The recording medium stores a program for causing the control unit 100 to perform the action confirmation method described later. The recording medium may also be a removable medium such as non-volatile semiconductor memory, magnetic disk, or optical disk. The memory 204 temporarily stores the program loaded on the recording medium in the storage 206 and the calculation results generated by the processor 202.

[0093] The processor 202, in conjunction with the memory 204, executes the aforementioned program to construct the various functional modules. The input / output port 208, following instructions from the processor 202, performs electrical signal input / output between the control device 18, the optical receiver 76, and the driver 80, etc. The timer 212, for example, measures elapsed time by calculating a reference pulse of a certain period. Furthermore, the hardware configuration of the control unit 100 is not necessarily limited to constructing the various functional modules through programs. For example, the various functional modules of the control unit 100 can also be constructed using dedicated logic circuits or integrated ASICs (Application Specific Integrated Circuits).

[0094] [Foreign Object Detection Methods] Then, referring to Figure 12, the foreign object detection method (foreign object detection sequence) implemented in the foreign object detection unit 50 will be explained. Figure 12 is a flowchart showing an example of the foreign object detection method.

[0095] While the illumination from the light source 72 continues, for example, if 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 control unit 108 is driven to move the slide 84 by the drive unit 80, thereby moving the irradiation unit 74 and the light receiving unit 76 to a position corresponding to the processing fluid flow path 64 through which the processing fluid being monitored, as shown in the processing information. Thereby, irradiation light is irradiated from the irradiation unit 74 onto the processing fluid flow path 64 through which the processing fluid being monitored flows, and the light receiving unit 76 receives the light emitted from the processing fluid flow path 64.

[0096] Next, the control unit 100 executes steps S02 and S03. In step S02, for example, the signal acquisition unit 102 acquires the signal intensity corresponding to the detection light received by the light receiving unit 76. In step S03, for example, the foreign object detection unit 104 determines whether the signal intensity acquired in step S02 is greater than the threshold Th. If in step S03 it is determined that the signal intensity is greater than the threshold 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 objects. On the other hand, if in step S03 it is determined that the signal intensity is below the threshold Th (step S03: NO), the control unit 100 does not execute step S04.

[0097] Next, the control unit 100 executes step S05. In step S05, for example, the control unit 100 determines whether the supply of the monitored processing fluid has ended. The control unit 100 may also measure the elapsed time from the start time of the supply included in the processing information to determine whether the supply of the processing fluid has ended. If in step S05 it is determined that the supply of the monitored processing fluid has not ended (step S05: NO), the control unit 100 repeats the processing of steps S02 and S03. In this way, monitoring of whether foreign matter is contained in the processing fluid continues during the supply period of the processing fluid.

[0098] In step S05, if it is determined that the supply of the processing fluid being monitored has ended (step S05: YES), the control unit 100 executes step S06. In step S06, for example, the control unit 100 determines whether there is a standby time based on the start time of the next supply of the processing fluid being monitored (hereinafter referred to as "the next supply start time"). As an example, if the time up to the start time of the next supply is longer than a predetermined time, it is determined that there is a standby time, and the control unit 100 executes step S07. In step S07, for example, the control unit 108 is driven to move the irradiation unit 74 and the light receiving unit 76 to the standby position using the drive unit 80.

[0099] Next, the control unit 100 executes step S08. In step S08, for example, the control unit 100 waits until the timing for starting monitoring of the next processing fluid to be monitored becomes available. For example, the control unit 100 waits until the time before the start of the next supply sequence becomes shorter than the predetermined time. If, in step S08, the timing for starting monitoring of the next processing fluid to be monitored becomes available (step S08: YES), or if, in step S06, it is determined that there is no wait time (step S06: NO), the control unit 100 repeats the processing steps S01 to S06.

[0100] [Methods for Adjusting Light Level] Next, referring to Figure 13, the method for adjusting the light intensity implemented in the foreign object detection unit 50 will be explained. Figure 13 is a flowchart showing an example of the light intensity adjustment method.

[0101] First, the control unit 100 executes step S11. In step S11, for example, the control unit 108 is driven to move the slide 84 via the drive unit 80, thereby moving the irradiation unit 74 and the light receiving unit 76 to a position corresponding to the processing fluid flow path 64 through which the processing fluid being monitored flows, as indicated by the processing information. Here, irradiation light is irradiated from the irradiation unit 74 onto the processing fluid flow path 64 through which the processing fluid being monitored flows, and the light receiving unit 76 receives the light emitted from the processing fluid flow path 64. Then, the signal acquisition unit 102 acquires the signal intensity corresponding to the detection light received by the light receiving unit 76. The measurement result obtained in this way becomes a measurement result of a specific light intensity. If necessary, the control unit 100 can repeat step S11 to obtain measurement results under multiple conditions with different light intensities.

[0102] Next, the control unit 100 executes step S12. In step S12, for example, the noise evaluation unit 112 identifies machine noise components and turbid noise components based on the signal intensity information obtained in step S11. As an example, the level of turbid noise components can also be identified based on whether there is a difference in the level of noise component N in the measurement conditions performed under two-stage light intensity, as described above. Alternatively, in step S12, the machine noise components and turbid noise components may not be explicitly distinguished. As an example, the degree of noise component N can also be identified in step S12. Furthermore, when the magnitude of the machine noise component is known, for example, if the noise component N is larger than the machine noise component, it indicates that the turbid noise component is larger than the machine noise component. The composition of the turbid noise component can also be inferred from this information. The noise component N can also be directly measured from the results when the light intensity is zero.

[0103] Next, the control unit 100 executes step S13. In step S13, for example, the light intensity adjustment unit 114 determines, based on the measurement results of a specific light intensity, whether the machine noise level and the turbid noise level are approximately the same level. The machine noise level is constant, while the turbid noise level varies with the light intensity. Therefore, when the light intensity is changed (reduced), it is possible to determine whether the machine noise level and the turbid noise level are approximately the same level based on whether the level of the noise component N changes.

[0104] If the turbidity noise level is higher than the machine noise level (step S13: NO), it is determined that there is room to reduce the turbidity noise level. In this case, as step S14, for example, the light intensity adjustment unit 114 of the control unit 100 can set the light intensity of the irradiation light irradiating the processing fluid flow path 64 to a lower level. Alternatively, steps S11 to S13 can be repeated while reducing the light intensity by one level.

[0105] When the turbidity noise level is equal to the machine noise level (step S13: YES), it is determined that there is no room to reduce the turbidity noise level. In this case, as step S15, for example, the light intensity adjustment unit 114 of the control unit 100 can be used to determine that the light intensity of the irradiation light irradiating the processing fluid flow path 64 is at its minimum condition. Furthermore, as step S16, for example, the light intensity adjustment unit 114 can be set to a condition that slightly increases the light intensity relative to the minimum condition as the measurement condition. The measurement condition refers to the light intensity when performing foreign matter detection in the processing fluid. Although the minimum light intensity condition can be used as the measurement condition, a state that slightly increases the light intensity compared to the minimum condition can also be adopted, taking into account small changes in light intensity.

[0106] Furthermore, the order of light intensity adjustment shown in Figure 13 can be applied, for example, to each processing solution. Since the composition of the processing solution varies depending on the solution, the level of turbidity noise may also change. Additionally, the light intensity can be adjusted for each processing solution flow path 64. The level of turbidity noise may change due to variations in the processing solution flow path 64; therefore, by applying the above order to each processing solution flow path 64, the light intensity can be adjusted in greater detail.

[0107] [Another example of a light-reducing component] Figure 14 shows another example of a light-reducing component operating as a light adjustment unit. Figure 14 shows an example where a beam splitter 82f, acting as a light-reducing component, is provided in the optical path instead of a reflector 82a. In this case, a portion of the light split by the beam splitter 82f is emitted into the processing liquid flow path 64. Alternatively, the other portion of the light split by the beam splitter 82f (light heading in a direction different from the processing liquid flow path 64) can be absorbed in a collecting section (not shown). In the configuration shown in Figure 14, similar to the other components included in the irradiation unit 74, the beam splitter 82f is held by a holding section 78 and moves in the Y-axis direction along with the movement of the slide 84 along the guide rail 88.

[0108] In this way, the configuration and arrangement of the light-reducing components can be appropriately modified. Furthermore, as other configurations of the light-reducing components, for example, it is possible to arrange the light-reducing components between the light source 72 and the reflecting component 82a. Additionally, it is possible to arrange any one of a plurality of light-reducing components with different optical characteristics in the optical path. In this case, for example, it is possible to arrange a plurality of light-reducing components on a rotator, rotate the rotator, and thereby arrange any one of the light-reducing components in the optical path. Furthermore, a plurality of light-reducing components can be arranged in the optical path, and it is also possible to achieve a configuration that optimizes the irradiated light through a plurality of light-reducing components.

[0109] Furthermore, it can also be configured to give the light source 72 itself a light adjustment function. For example, the intensity of the light emitted from the light source 72 can also be adjusted. In the foreign object detection unit U3, various light-reducing components can be provided as described above, and thus it can also be configured to combine them to adjust the amount of light irradiating the processing liquid flow path 64.

[0110] [effect] According to the aforementioned foreign object detection device and method, after the light emitted from the light source 72 is adjusted by the light-reducing filter 82c (or beam splitter 82f) included in the irradiation unit 74, which functions as a light adjustment unit, the light is then irradiated onto the processing fluid flow path 64. The amount of light irradiating the plurality of processing fluid flow paths 64 can be adjusted. Therefore, in cases where processing fluids with different characteristics flow through the plurality of processing fluid flow paths, or where flow conditions such as flow rate / volume are different, the amount of light irradiating these plurality of processing fluid flow paths can be adjusted, thus enabling efficient foreign object detection corresponding to the state of the processing fluid in each processing fluid flow path 64.

[0111] Alternatively, the irradiation unit 74 can be positioned such that it moves relative to the plurality of processing liquid flow paths 64, thereby irradiating each of the plurality of processing liquid flow paths 64 with irradiation light. Furthermore, a light adjustment unit can be provided on each light path leading to the plurality of processing liquid flow paths 64. In this case, the light intensity of each processing liquid flow path can be adjusted individually, thus allowing for flexible adjustment of the light intensity.

[0112] The light adjustment unit can also adjust the intensity of the irradiation light based on the noise components contained in the light received by the light receiving unit 76 when irradiating one of the plurality of processing fluid flow paths 64. Specifically, the intensity of the irradiation light irradiating a processing fluid flow path 64 is adjusted to a level not lower than the intensity of normal noise components generated regardless of the intensity of the irradiation light, so that the intensity of the turbid noise components, which varies with the intensity of the irradiation light, is close to the intensity of normal noise. The turbid noise components in the noise components contained in the light received by the light receiving unit 76 are components that vary with the intensity of the irradiation light. Therefore, by adjusting the intensity of the irradiation light to be close to the intensity of normal noise components, the reduction in the accuracy of foreign object detection can be prevented, and by adjusting the intensity of the irradiation light to be reduced, efficient foreign object detection corresponding to the state of the processing fluid can be performed.

[0113] The system may further include a control unit 100 that acquires an electrical signal corresponding to the intensity of the light received by the light receiving unit 76. In this case, the control unit 100 can estimate the intensity of the normal noise component and the intensity of the turbid noise component based on the electrical signal corresponding to the light received by the light receiving unit 76 when irradiating a processing fluid flow path 64 with irradiation light. Furthermore, the light adjustment unit can adjust the amount of irradiation light irradiating a processing fluid flow path 64 based on the estimation result of the control unit 100, so that the intensity of the turbid noise component, which varies according to the intensity of the irradiated light, is close to the intensity of the normal noise component. By adopting the above configuration, the intensity of the normal noise component and the intensity of the turbid noise component can be estimated based on the electrical signal corresponding to the light received by the light receiving unit 76, and the amount of irradiation light can be adjusted accordingly. Therefore, the intensity of the irradiation light can be adjusted with greater precision.

[0114] Alternatively, the control unit 100 can estimate the intensity of normal noise components and the intensity of cloudy noise components based on the electrical signals received by the light receiving unit 76 when irradiating light with different amounts of light onto a processing fluid flow path 64. The intensity of the cloudy noise components can vary according to the intensity of the irradiated light. Therefore, by estimating the intensity of normal noise components and cloudy noise components based on the difference in light received by the light receiving unit 76 when irradiating light with different amounts of light, the relationship between cloudy noise components and normal noise components can be estimated more accurately.

[0115] [Variation Example] The above descriptions are for various illustrative embodiments, but are not limited to these illustrative embodiments. Various omissions, substitutions, and changes are also possible. Furthermore, elements from different embodiments can be combined to form another embodiment.

[0116] The above-described foreign object inspection sequence is just one example; the order of steps, timing, and content can be appropriately changed.

[0117] Furthermore, the configuration of the foreign object inspection device can be appropriately modified. For example, at least a portion of the processing fluid flow path 64 flowing through the block body 66 can be formed in a direction other than the horizontal and vertical directions. Alternatively, the inlet 64a and outlet 64b of the processing fluid flow path 64 can be formed on different surfaces within the block body.

[0118] The processing fluid flow path forming units 62A-62L may replace the main body 66 and include a supply pipe for allowing the processing fluid to flow. The processing fluid flow path 64 may also be a flow path within the supply pipe. These supply pipes may also be made of a material that is translucent to light (e.g., quartz or sapphire). The foreign object detection unit 50 may also replace the processing fluid flow path forming units 62A-62L and have a processing fluid flow path forming unit.

[0119] The processing fluid flow path forming units 62A~62L can be arranged along the Y-axis with roughly the same interval between them, or they can be arranged with different intervals between them. In addition, as part of the processing fluid flow path forming units, one or more dummy flow path forming units that are not used in the processing can also be arranged.

[0120] The optical characteristics of the neutral density filter 82c can be selected according to the characteristics of the processing fluid as described above. However, for example, a dummy filter, i.e., an optical filter without neutral density function, can also be placed on the optical path up to the processing fluid flow path 64. For example, if the processing fluid is a diluent, there is a case where no neutral density component is provided. In this case, if the configuration is such that no neutral density component is provided for multiple processing fluid flow paths 64, there is a possibility that the optical path length will differ in each processing fluid flow path. In contrast, by configuring an optical filter without neutral density function on the optical path in the same way as the other processing fluid flow paths 64, the optical path length can be made consistent.

[0121] The foreign object detection unit 50 may also include an irradiation drive unit for moving the irradiation unit 74 along the Y-axis direction, and a light receiving drive unit for moving the light receiving unit 76 along the Y-axis direction. These two drive units may also be configured to move the irradiation unit 74 and the light receiving unit 76 along the Y-axis direction. Furthermore, an X-axis drive unit may also be provided to move the light receiving unit 76 along the X-axis direction. The irradiation unit 74 may also include a light source 72 to irradiate the processing liquid flow path 64 with irradiation light without passing through the optical component 82.

[0122] The light receiving unit 76 can also receive a portion of the transmitted light obtained by passing the irradiation light from the irradiation unit 74 through the processing liquid flow path 64. In this case, the irradiation unit 74 and the light receiving unit 76 can be arranged such that the processing liquid flow path forming units 62A~62L are sandwiched between them in the vertical direction (Z-axis direction).

[0123] Furthermore, the specific configuration of the substrate processing apparatus is not limited to the configuration of the coating and developing apparatus 2 illustrated above. Any type of apparatus can be used if it includes a foreign matter detection unit 50 for detecting foreign matter in the processing liquid supplied to the substrate. The processing liquid, which is the target liquid for foreign matter detection by the foreign matter detection unit 50, can be a solution used for forming films other than photoresist films (such as the aforementioned lower or upper film), or a solution used 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 can be implemented by the control device 18. In this case, the foreign matter detection unit 50 and the control device 18 can be used to construct a foreign matter detection apparatus.

[0124] As can be seen from the above description, the various embodiments of the present invention are described in this specification for illustrative purposes, and it should be understood that various modifications can be made without departing from the scope and spirit of the present invention. Therefore, the various embodiments disclosed in this specification are not intended to limit the present invention, and the true scope and spirit are shown by the appended claims.

[0125] 1: Substrate processing system 11, 12, 13, 14: Processing Modules 18: Control device 2: Coating and developing apparatus 20: Rotary retaining part 22: Maintaining section 24: Rotary drive unit 3: Exposure device 30: Processing Fluid Supply Department 32, 32A~32L: Nozzles [] 34: Keep your head up 36: Supply Department 4: Vehicle Block 42A~42L: Supply pipe 44A~44L: Supply Source 46: Upstream supply pipe 48: Downstream supply pipe 5: Processing Blocks 50: Foreign object detection unit (foreign object detection device) 52: Shell 54a: Upper wall 54b: Bottom wall 56a~56d: Sidewall 58: Heatsink 6: Interface Block 60: Flow path forming part 62A~62L: Processing fluid flow path forming section 64: Processing fluid flow path 64a: Inlet 64b: Outlet 66:Block body 68a: 1st flow path 68b: 2nd flow path 68c: 3rd flow path 70: Measurement Department 72: Light source 74: Irradiation Department 76: Optical receiver 78: Maintaining Section 80: Drive Unit 82: Optical components 82a: Reflective component 82b: Condensing Lens 82c: Neutral Density Filter 82d:Collection Department 82e: Support Components 82f: Beam splitter 84:Slide 86: Supporting components 88: Guide rail 92: Optical components 94: Optical receiving element 100: Control Department 102: Signal Acquisition Department 104: Foreign Object Detection Department 106: Information Acquisition Processing Department 108: Drive Control Department 110: Output Department 112: Noise Evaluation Department 114: Light Adjustment Department 200: Circuit 202: Processor 204: Memory 206: Storage 208: Input / Output Ports 212: Timer A1, A3, A7, A8: Handling devices Ax: Axis line C: Vehicle PS1~PS3: Signal U1: Liquid Handling Unit U2: Heat Treatment Unit U3: Foreign Object Detection Unit U10, U11: Shelving Units V: On / off valve W: Workpiece Wa:front

Claims

1. A foreign matter detection device for detecting foreign matter contained in a processing liquid for substrate processing, comprising: a plurality of processing liquid flow path forming sections, each forming a plurality of processing liquid flow paths through which the processing liquid supplied to the substrate flows; an irradiation section capable of individually irradiating each of the plurality of processing liquid flow paths with irradiation light from a light source; and a light receiving section for receiving light emitted from the processing liquid flow path by irradiation with the irradiation light; the irradiation section comprising a light adjustment section that makes the light intensity of the irradiation light irradiating the plurality of processing liquid flow paths different from each other; the light adjustment section adjusting the light intensity of the irradiation light irradiating a processing liquid flow path to a condition not lower than the intensity of a normal noise component, which is generated regardless of the intensity of the irradiation light, in the light received by the light receiving section when the irradiation light is irradiated on one of the plurality of processing liquid flow paths, so that the intensity of the turbid noise component, which varies with the intensity of the irradiation light, is close to the intensity of the normal noise component.

2. The foreign object detection device as described in claim 1, wherein, The irradiation unit can irradiate the plurality of processing fluid flow paths with irradiation light by moving them relative to each of the plurality of processing fluid flow paths; the light adjustment unit is provided on the light path leading to each of the plurality of processing fluid flow paths.

3. The foreign object detection device as described in request item 1 or 2, wherein, It 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 normal noise component and the intensity of the turbid 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 processing fluid flow path; the light adjustment unit adjusts the amount of the irradiation light irradiating the processing fluid flow path based on the estimation result of the control unit, so that the intensity of the turbid noise component, which varies with the intensity of the irradiation light, is close to the intensity of the normal noise component.

4. The foreign object detection device as described in claim 3, wherein, The control unit estimates the intensity of the normal noise component and the intensity of the turbid noise component based on the electrical signal corresponding to the light received in the light receiving unit when the amount of light irradiated is different from that of the light irradiated to the processing fluid flow path.

5. A foreign matter detection device for detecting foreign matter contained in a processing liquid for substrate processing, comprising: an irradiation unit capable of irradiating a processing liquid flow path through which the processing liquid supplied to the substrate flows with irradiation light from a light source; and a light receiving unit capable of receiving light emitted from the processing liquid flow path by irradiation with the irradiation light; the irradiation unit including a light adjustment unit for adjusting the light intensity of the irradiation light; the light adjustment unit adjusting the light intensity of the irradiation light irradiating the processing liquid flow path to a condition not lower than the intensity of a normal noise component generated regardless of the intensity of the irradiation light in the noise component contained in the light received by the light receiving unit when the irradiation light is irradiated onto the processing liquid flow path, so that the intensity of the turbid noise component that varies with the intensity of the irradiation light is close to the intensity of the normal noise component.

6. The foreign object detection device of claim 5 further includes: a control unit that acquires an electrical signal corresponding to the intensity of light received by the light receiving unit; the control unit that estimates the intensity of the normal noise component and the intensity of the turbid 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 processing fluid flow path; and a light adjustment unit that adjusts the amount of light irradiated onto the processing fluid flow path based on the estimation result of the control unit, so that the intensity of the turbid noise component, which varies with the intensity of the irradiation light, is close to the intensity of the normal noise component.

7. The foreign object detection device as described in claim 6, wherein, The control unit estimates the intensity of the normal noise component and the intensity of the turbid noise component based on the electrical signal received by the light receiving unit when the amount of light irradiated is different from that of the light irradiating the flow path of the processing liquid.

8. A foreign object detection device as described in any of claims 5 to 7, wherein, The irradiation unit can individually irradiate the irradiation light onto each of the plurality of processing fluid flow paths, and includes a plurality of light adjustment units corresponding to the plurality of processing fluid flow paths respectively; each of the plurality of light adjustment units adjusts the amount of irradiation light irradiating the corresponding processing fluid flow path so that the intensity of the turbid noise component is close to the intensity of the normal noise component.

9. A foreign matter detection method, which is a foreign matter detection device for detecting foreign matter contained in a processing liquid for substrate processing, comprising the following steps: irradiating a plurality of processing liquid flow paths through which the processing liquid supplied to the substrate flows with an irradiation unit by irradiating light from a light source; and receiving light emitted from the processing liquid flow paths by irradiation with a light receiving unit; the step of irradiating the irradiation light comprising: making the light intensity of the irradiation light irradiating the plurality of processing liquid flow paths different from each other by a light adjustment unit; and adjusting the light intensity of the irradiation light irradiating a processing liquid flow path by the light adjustment unit to a condition not lower than the intensity of the normal noise component generated regardless of the intensity of the irradiation light in the noise component contained in the light received by the light receiving unit when the irradiation light is irradiated in one of the plurality of processing liquid flow paths, so that the intensity of the turbid noise component that varies with the intensity of the irradiation light is close to the intensity of the normal noise component.

10. The foreign object detection method as described in request item 9, wherein, By moving the irradiation unit relative to the plurality of processing fluid flow paths, the irradiation light is irradiated onto the plurality of processing fluid flow paths respectively.

11. The foreign matter detection method of claim 9 further includes the following steps: estimating the intensity of the normal noise component and the intensity of the turbid noise component based on the electrical signal corresponding to the light received at the light receiving unit when the irradiation light is irradiated on the processing fluid flow path.

12. The foreign object detection method as described in request item 11, wherein, The intensity of the normal noise component and the intensity of the turbid noise component are estimated from the electrical signal corresponding to the light received at the light receiving unit when the amount of light irradiated is different from that of the light irradiating the processing fluid flow path.

13. A foreign matter detection method, which is a foreign matter detection device for detecting foreign matter contained in a processing liquid for substrate processing, comprising the following steps: irradiating a processing liquid flow path through which the processing liquid supplied to the substrate flows with irradiation light from a light source; receiving light emitted from the processing liquid flow path by irradiation with the irradiation light; and adjusting the amount of irradiation light irradiating the processing liquid flow path to a condition not lower than the intensity of a normal noise component generated regardless of the intensity of the irradiation light in the noise component contained in the received light when the irradiation light is irradiated, so that the intensity of the turbid noise component that varies with the intensity of the irradiation light is close to the intensity of the normal noise component.

14. The foreign matter detection method of claim 13 further includes the following steps: estimating the intensity of the normal noise component and the intensity of the turbid noise component based on the electrical signal corresponding to the light received when the processing fluid flow path is irradiated with the irradiation light.

15. The foreign object detection method as described in claim 14, wherein, The intensity of the normal noise component and the intensity of the turbid noise component are estimated from the electrical signal corresponding to the light received when the irradiation light is different from that of the irradiation light on the flow path of the processing liquid.

16. A foreign object detection method as described in any of claims 13 to 15, wherein, The illumination light is individually applied to each of the plurality of processing fluid flow paths; the intensity of the illumination light applied to each of the plurality of processing fluid flow paths is individually adjusted so that the intensity of the turbid noise component is close to the intensity of the normal noise component.

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