JP7565387B2 - SUBSTRATE PROCESSING APPARATUS, SUBSTRATE PROCESSING METHOD, AND STORAGE MEDIUM - Google Patents

Description

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

Patent document 1 discloses a coating apparatus equipped with a particle measuring device that measures particles in the resist liquid supplied from a sampling pipe.

Japanese Patent Application Publication No. 10-209024

The present disclosure provides a substrate processing apparatus, a substrate processing method, and a storage medium that enable easy understanding of the cause of an event that leads to foreign object detection.

A substrate processing apparatus according to one aspect of the present disclosure includes a processing liquid supply unit having a nozzle capable of ejecting a processing liquid, a processing liquid supply source, and a supply flow path connecting the nozzle and the supply source, and supplying the processing liquid to a substrate; a plurality of foreign object detection units arranged at different positions along the supply flow path and detecting foreign objects contained in the processing liquid based on a light reception signal obtained by receiving light emitted from within the supply flow path in response to light irradiation; and a source estimation unit that estimates a section of the supply flow path in which an event causing the detection of a foreign object occurred, based on the detection results at each of the plurality of positions by the plurality of foreign object detection units.

The present disclosure provides a substrate processing apparatus, a substrate processing method, and a storage medium that can easily grasp the cause of an event that causes foreign object detection.

FIG. 1 is a schematic perspective view showing an example of a substrate processing system. FIG. 2 is a schematic side view showing an example of a coating and developing apparatus. FIG. 3 is a schematic diagram illustrating an example of the liquid processing unit. FIG. 4 is a schematic diagram showing an example of a processing liquid supply unit. FIG. 5 is a schematic diagram showing an example of a foreign object detection unit. FIG. 6 is a block diagram illustrating an example of a functional configuration of the control system. FIG. 7 is a graph showing an example of a light receiving signal used for foreign object detection. FIG. 8 is a graph showing an example of accumulated data in each foreign object detection unit. FIG. 9 is a block diagram illustrating an example of a hardware configuration of the control system. FIG. 10 is a flowchart showing an example of a series of processes executed by the control system. FIG. 11 is a graph showing an example of the measurement results of the flow velocity of the treatment liquid. FIG. 12 is a graph showing an example of the relationship between the type of chemical solution and the intensity of background light. FIG. 13 is a graph showing an example of accumulated data in each foreign object detection unit.

Various exemplary embodiments are described below.

A substrate processing apparatus according to one exemplary embodiment includes a processing liquid supply unit having a nozzle capable of ejecting a processing liquid, a processing liquid supply source, and a supply flow path connecting the nozzle and the supply source, and supplying the processing liquid to a substrate; a plurality of foreign object detection units arranged at different positions along the supply flow path and detecting foreign objects contained in the processing liquid based on a light reception signal obtained by receiving light emitted from within the supply flow path in response to light irradiation; and a source estimation unit that estimates a section of the supply flow path in which an event causing the detection of a foreign object occurred, based on the detection results at each of the plurality of positions by the plurality of foreign object detection units.

One possible method is to detect foreign matter in the processing liquid by disposing a foreign matter detection unit at one location in the supply flow path between the nozzle and the supply source. With this method, it is possible to determine that a foreign matter has occurred in the processing liquid, but it is not possible to determine from the detection results what caused the foreign matter to occur in the processing liquid. In contrast, in the above-mentioned substrate processing apparatus, the section in the supply flow path where the event that caused the detection of the foreign matter occurred is estimated from the foreign matter detection results at multiple locations on the supply flow path. Therefore, by using the estimation results, it is possible to easily determine the cause of the occurrence of the above-mentioned event.

The treatment liquid supply unit may have a liquid delivery unit including a filter for collecting foreign matter contained in the treatment liquid in the supply flow path and a pump for delivering the treatment liquid toward the nozzle, a discharge valve for opening and closing a flow path between the liquid delivery unit and the nozzle in the supply flow path, and a refilling unit for refilling the treatment liquid from a supply source to the liquid delivery unit. The multiple foreign matter detection units may have a first foreign matter detection unit arranged in the flow path between the nozzle and the discharge valve, a second foreign matter detection unit arranged in the flow path between the discharge valve and the liquid delivery unit, and a third foreign matter detection unit arranged in the flow path between the refilling unit and the liquid delivery unit. In this case, it is possible to estimate, from the detection results by the first foreign matter detection unit, the second foreign matter detection unit, and the third foreign matter detection unit, that the section in which an event causing the detection of a foreign matter is assumed to have occurred is either a section including the discharge valve, a section including the liquid delivery unit, or a section including the refilling unit.

The substrate processing apparatus may further include a factor estimation unit that estimates the cause of the occurrence of the event according to the section estimated by the source estimation unit. In this case, by using the result of the factor estimation by the factor estimation unit, it becomes possible to more easily grasp the cause of the occurrence of the event.

The substrate processing apparatus may further include a flow rate measurement unit that measures the flow rate of the processing liquid flowing through a flow path that guides the processing liquid to the nozzle. The cause estimation unit may narrow down the causes of the occurrence of the above-mentioned event based on the measurement results by the flow rate measurement unit. In this case, since the causes of the occurrence of the above-mentioned event are narrowed down, it becomes possible to more easily grasp the causes of the occurrence of the above-mentioned event.

The cause estimation unit may narrow down the causes of the occurrence of the above-mentioned event based on the frequency of supply of the processing liquid to the substrate when the above-mentioned event occurs. In this case, since the causes of the occurrence of the above-mentioned event are narrowed down, it becomes possible to more easily grasp the causes of the occurrence of the above-mentioned event.

Each of the multiple foreign object detection units may detect another chemical liquid contained in the processing liquid as a foreign object based on intensity information indicating the intensity of background light contained in the emitted light. The intensity of the background light varies depending on the type of liquid, such as the processing liquid. In the above configuration, by using the intensity information, it becomes possible to easily determine whether another chemical liquid is contained as a foreign object in the processing liquid.

A substrate processing method according to one exemplary embodiment includes supplying a processing liquid to a substrate from a nozzle capable of discharging the processing liquid, detecting foreign matter contained in the processing liquid at a plurality of different positions along a supply flow path connecting a processing liquid source and the nozzle based on a light reception signal obtained by receiving light emitted from the supply flow path in response to light irradiation, and estimating a section of the supply flow path in which an event causing the detection of the foreign matter occurred based on the detection results of the foreign matter at each of the plurality of positions. With this substrate processing method, it is possible to easily grasp the cause of the occurrence of the above-mentioned event, as with the substrate processing apparatus described above.

In one exemplary embodiment, the storage medium is a computer-readable storage medium storing a program for causing an apparatus to execute the above-mentioned substrate processing method.

Several embodiments will be described below with reference to the drawings. In the description, identical elements or elements having the same functions are given the same reference numerals, and duplicate descriptions will be omitted.

[First embodiment]
First, a substrate processing system 1 according to a first embodiment will be described with reference to Figs. 1 to 11. The substrate processing system 1 (substrate processing apparatus) shown in Fig. 1 is a system that performs the formation of a photosensitive film on a workpiece W, the exposure of the photosensitive film, and the development of the photosensitive film. The workpiece W to be processed is, for example, a substrate, or a substrate on which a film or a circuit or the like has been formed by performing a predetermined process. As an example, the substrate is a silicon wafer. The workpiece W (substrate) may be circular. The workpiece W may be a glass substrate, a mask substrate, or an FPD (Flat Panel Display), etc. The photosensitive film is, for example, a resist film.

As shown in Figures 1 and 2, the substrate processing system 1 includes a coating and developing apparatus 2, an exposure apparatus 3, and a control device 20. The coating and developing apparatus 2 applies resist (chemical solution) to the surface of the workpiece W to form a resist film before exposure processing by the exposure apparatus 3, and develops the resist film after exposure processing. The exposure apparatus 3 is an apparatus that exposes a resist film (photosensitive coating) formed on the workpiece W (substrate). Specifically, the exposure apparatus 3 irradiates an energy beam onto an exposure target portion of the resist film by a method such as immersion exposure. The coating and developing apparatus 2 includes a carrier block 4, a processing block 5, and an interface block 6.

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

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

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

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

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

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

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

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

The control device 20 controls the coating and developing device 2 to perform a coating and developing process, for example, in the following manner. First, the control device 20 controls the transport device A1 to transport the work W in the carrier C to the shelf unit U10, and then controls the transport device A7 to place the work W in a cell for the processing module 11.

Next, the control device 20 controls the transport device A3 to transport the workpiece W from the shelf unit U10 to the liquid treatment unit U1 and heat treatment unit U2 in the processing module 11. The control device 20 also controls the liquid treatment unit U1 and heat treatment unit U2 to form an underlayer film on the surface of the workpiece W. Thereafter, the control device 20 controls the transport device A3 to return the workpiece W with the underlayer film formed thereon to the shelf unit U10, and controls the transport device A7 to place the workpiece W in a cell for the processing module 12.

Next, the control device 20 controls the transport device A3 to transport the workpiece W from the shelf unit U10 to the liquid treatment unit U1 and heat treatment unit U2 in the processing module 12. The control device 20 also controls the liquid treatment unit U1 and heat treatment unit U2 to form a resist film on the surface of the workpiece W. Thereafter, the control device 20 controls the transport device A3 to return the workpiece W to the shelf unit U10, and controls the transport device A7 to place the workpiece W in a cell for the processing module 13.

Next, the control device 20 controls the transport device A3 to transport the workpiece W from the shelf unit U10 to each unit in the processing module 13. The control device 20 also controls the liquid processing unit U1 and the heat processing unit U2 to form an upper layer film on the resist film of the workpiece W. Thereafter, the control device 20 controls the transport device A3 to transport the workpiece W to the shelf unit U11.

Next, the control device 20 controls the transport device A8 to send the workpiece W in the shelf unit U11 to the exposure device 3. The control device 20 then controls the transport device A8 to receive the workpiece W that has been subjected to the exposure process from the exposure device 3 and place it in a cell for the processing module 14 in the shelf unit U11.

The control device 20 then controls the transport device A3 to transport the workpiece W from the shelf unit U11 to each unit in the processing module 14, and controls the liquid processing unit U1 and the heat processing unit U2 to perform development processing of the resist film on the workpiece W. The control device 20 then controls the transport device A3 to return the workpiece W to the shelf unit U10, and controls the transport device A7 and the transport device A1 to return the workpiece W into the carrier C. This completes the coating and developing processing for one workpiece W. The control device 20 then causes the coating and developing device 2 to perform the coating and developing processing for each of the subsequent multiple workpieces W in the same manner as described above.

The specific configuration of the substrate processing apparatus is not limited to the configuration of the substrate processing system 1 exemplified above. The substrate processing apparatus may be any type that includes a liquid processing unit that supplies processing liquid to the substrate and performs liquid processing, and a control device that can control the liquid processing unit.

(Liquid processing unit)
3 and 4, an example of the liquid processing unit U1 in the processing module 12 will be described in detail. As shown in FIG.

The rotating holding unit 22 holds and rotates the workpiece W based on the operational instructions of the control device 20. The rotating holding unit 22 has a holding unit 24 and a drive unit 26. The holding unit 24 supports the center of the workpiece W arranged horizontally with its surface Wa facing upward, and holds the workpiece W by suction (e.g., vacuum suction) or the like. The drive unit 26 is a rotary actuator including a power source such as an electric motor, and rotates the holding unit 24 around a vertical rotation axis. This causes the workpiece W to rotate around the vertical rotation axis.

The treatment liquid supply unit 28 supplies the treatment liquid to the workpiece W. The treatment liquid supply unit 28 has a nozzle 30 capable of ejecting the treatment liquid, and a supply flow path 29 that guides the treatment liquid from a source of the treatment liquid (supply source 52 described below) to the nozzle 30, and supplies the treatment liquid to the surface Wa of the workpiece W. As shown in FIG. 4, for example, the treatment liquid supply unit 28 has a nozzle 30, a liquid delivery pipe 32, a discharge valve 34, a liquid delivery unit 40, a liquid delivery pipe 36, and a refill unit 50. In the following description, the terms "upstream" and "downstream" are used based on the flow of the treatment liquid.

The nozzle 30 ejects the processing liquid onto the workpiece W. For example, the nozzle 30 is positioned above the workpiece W and ejects the processing liquid downward (see also FIG. 3). The processing liquid is ejected from the nozzle 30 toward the workpiece W, so that the processing liquid is applied (supplied) to the surface Wa of the workpiece W. The liquid delivery tube 32 connects the nozzle 30 and the liquid delivery section 40, and forms a flow path that guides the processing liquid to the nozzle 30. The downstream end of the liquid delivery tube 32 is connected to the nozzle 30, and the upstream end of the liquid delivery tube 32 is connected to the liquid delivery section 40.

The discharge valve 34 is provided in the flow path of the processing liquid formed by the liquid supply pipe 32. The discharge valve 34 opens and closes the flow path in the liquid supply pipe 32 (the flow path between the liquid supply section 40 and the nozzle 30) based on an operation instruction from the control device 20. When the discharge valve 34 is in an open state, the processing liquid is discharged from the nozzle 30 toward the surface Wa of the workpiece W, and when the discharge valve 34 is in a closed state, the discharge of the processing liquid from the nozzle 30 is stopped. The discharge valve 34 is, for example, an air-operated valve.

The liquid delivery unit 40 delivers the treatment liquid to the nozzle 30 via the liquid delivery tube 32. Specifically, the liquid delivery unit 40 delivers the treatment liquid toward the nozzle 30 at a predetermined pressure. The liquid delivery unit 40 has, for example, a pump 42, a connecting tube 44, and a filter 46.

The pump 42 receives the processing liquid replenished from the refill section 50, pressurizes the received processing liquid, and sends it out toward the nozzle 30. The pump 42 has a storage chamber that stores the processing liquid, and a contraction section that expands and contracts the storage chamber. The pump 42 expands the storage chamber by the contraction section to receive the processing liquid, and contracts the storage chamber by the contraction section to send out the processing liquid. A tubephragm pump, a diaphragm pump, or a bellows pump may be used as the pump 42.

The connecting pipe 44 connects the pump 42 and the filter 46. The downstream end of the connecting pipe 44 is connected to the pump 42, and the upstream end of the connecting pipe 44 is connected to the filter 46. The connecting pipe 44 forms part of a flow path that guides the processing liquid replenished from the refilling unit 50 to the pump 42. The filter 46 collects foreign matter contained in the processing liquid flowing through the flow path from the refilling unit 50 to the pump 42.

The liquid supply pipe 36 connects between the filter 46 and the refilling unit 50. The downstream end of the liquid supply pipe 36 is connected to the liquid supply unit 40 (filter 46), and the upstream end of the liquid supply pipe 36 is connected to the refilling unit 50. The liquid supply pipe 36 and the connecting pipe 44 form a flow path for the treatment liquid from the refilling unit 50 to the pump 42.

The refilling unit 50 refills the liquid delivery unit 40 with the processing liquid to be sent toward the nozzle 30. As described above, a flow path for the processing liquid is formed between the refilling unit 50 and the pump 42 by the liquid delivery pipe 36 and the connecting pipe 44, and a filter 46 is provided in the flow path. The refilling unit 50 has, for example, a supply source 52, a liquid delivery pipe 54, a storage tank 56, and a pump 58.

The supply source 52 is a supply source of the processing liquid that is replenished to the liquid delivery section 40. The supply source 52 is, for example, a bottle that contains the processing liquid. The supply source 52 supplies the processing liquid to the pump 58 via the liquid delivery pipe 54. The storage tank 56 is provided in the liquid delivery pipe 54 and temporarily stores the processing liquid to be supplied to the pump 58.

The pump 58 receives the treatment liquid from the storage tank 56 and sends the received treatment liquid in a pressurized state through the liquid delivery tube 36 to the liquid delivery section 40 (through the liquid delivery tube 36 and the connecting tube 44 to the pump 42). The pump 58 has a storage chamber that stores the treatment liquid and a contraction section that expands and contracts the storage chamber. The pump 58 receives the treatment liquid by expanding the storage chamber with the contraction section, and sends out the treatment liquid by contracting the storage chamber with the contraction section. A tube phragm pump, a diaphragm pump, or a bellows pump may be used as the pump 58.

In the above-described processing liquid supply unit 28, the supply flow path 29 connecting the supply source 52 and the nozzle 30 is formed by the liquid supply pipe 54 of the refill unit 50, the liquid supply pipe 36, the connection pipe 44 of the liquid supply unit 40, and the liquid supply pipe 32. Various components (parts) that may be sources of foreign matter contained in the processing liquid discharged from the nozzle 30 are provided in the supply flow path 29. These various components constitute the processing liquid supply unit 28. In the above-described processing liquid supply unit 28, the supply source 52, the storage tank 56, the pump 58, the filter 46, the pump 42, and the discharge valve 34 correspond to various components that may be sources of foreign matter.

(Foreign object detection unit)
The coating and developing apparatus 2 includes a plurality of foreign matter detection units 70 (a plurality of foreign matter detection sections). Each foreign matter detection unit 70 is configured to detect foreign matter (particles) contained in the processing liquid flowing through the supply flow path 29. In the present disclosure, the "foreign matter" in the processing liquid includes solid foreign matter such as dust and dirt, as well as gaseous foreign matter such as bubbles. Detecting foreign matter means detecting that foreign matter is contained in the processing liquid (determining that foreign matter is contained). The foreign matter detection unit 70 receives light (emitted light) generated when the processing liquid flowing through the supply flow path 29 is irradiated with light (irradiation light) from a light source, and detects foreign matter based on a signal corresponding to the received light.

The multiple foreign object detection units 70 are arranged at multiple locations along the supply flow path 29 at different positions. In this case, the supply flow path 29 is divided into multiple sections (areas) by the multiple foreign object detection units 70. The multiple foreign object detection units 70 that are adjacent to each other in the supply flow path 29 are arranged so that at least one of the above-mentioned components is included in the section between those units. The foreign object detection unit 70 located most upstream among the multiple foreign object detection units 70 is arranged so that at least one of the above-mentioned components is located in the section upstream of that unit. Each foreign object detection unit 70 detects foreign objects contained in the processing liquid in the supply flow path 29 at the location where it is arranged.

The coating and developing apparatus 2 includes, for example, a plurality of foreign matter detection units 70, such as foreign matter detection unit 70A, foreign matter detection unit 70B, and foreign matter detection unit 70C. Below, a case will be described in which foreign matter detection units 70A to 70C are provided at different positions along the direction in which the processing liquid flows on the supply flow path 29. Foreign matter detection units 70A to 70C are provided in this order from nozzle 30 along the supply flow path 29.

The foreign object detection unit 70A (first foreign object detection unit) is disposed in the flow path of the supply flow path 29 between the discharge valve 34 and the nozzle 30. The foreign object detection unit 70B (second foreign object detection unit) is disposed in the flow path of the supply flow path 29 between the discharge valve 34 and the liquid delivery unit 40. The foreign object detection unit 70C (third foreign object detection unit) is disposed in the flow path of the supply flow path 29 between the liquid delivery unit 40 and the refill unit 50.

A discharge valve 34 is disposed as a component in the compartment between foreign object detection unit 70A and foreign object detection unit 70B. A pump 42 and a filter 46 are disposed as components in the compartment between foreign object detection unit 70B and foreign object detection unit 70C. A supply source 52 (bottle), a storage tank 56, and a pump 58 are disposed as components in the compartment upstream of foreign object detection unit 70C.

As described above, foreign object detection units 70A-70C are arranged along supply flow path 29, so that if a foreign object is generated in the processing liquid in a section upstream of foreign object detection unit 70C, the foreign object will pass through foreign object detection units 70C, 70B, and 70A in that order. Examples of cases in which foreign objects are generated in the processing liquid include cases in which foreign objects such as dust that were present inside a part, etc., are mixed into the processing liquid, and cases in which foreign objects such as bubbles are formed in the processing liquid.

The amount of processing liquid discharged from the nozzle 30 per one time (supply amount) is set to a value smaller than the piping volume of each section divided by the foreign object detection units 70A to 70C of the supply flow path 29. In this case, the amount of foreign objects moving downstream in the supply flow path 29 during one supply of processing liquid is shorter than the length of each section. Therefore, there is a difference in the number of times that a foreign object generated in the processing liquid in any section can be detected by each of the foreign object detection units 70A to 70C. As a result, it is possible to estimate the section in the supply flow path 29 where an event that causes the detection of a foreign object has occurred from the detection results of the foreign object detection units 70A to 70C. Examples of events that cause the detection of a foreign object (hereinafter simply referred to as "events") include the inclusion of a foreign object in the processing liquid and the generation of bubbles in the processing liquid.

For example, if a foreign object is detected by the foreign object detection unit 70A, but no foreign object has been detected in the foreign object detection units 70B and 70C in the past, it is assumed that the above event occurred in the section between the foreign object detection units 70A and 70B. In this case, it can be presumed that the discharge valve 34 is the source of the foreign object. If a foreign object is detected by the foreign object detection unit 70A, but a foreign object has already been detected in the foreign object detection unit 70B, and no foreign object has been detected in the foreign object detection unit 70C in the past, it can be presumed that the above event occurred in the section between the foreign object detection units 70B and 70C. In this case, it can be presumed that at least one of the pump 42 and the filter 46 included in the liquid delivery section 40 is the source of the foreign object.

When a foreign object is detected by foreign object detection unit 70A, if foreign objects have already been detected by foreign object detection units 70B and 70C, it is presumed that the above-mentioned event occurred in a section upstream of foreign object detection unit 70C. In this case, it can be presumed that at least one of the supply source 52, storage tank 56, and pump 58 included in the refill section 50 is the source of the foreign object. A specific example of a method for presuming the section in which the above-mentioned event is presumed to have occurred (the section presumed to include the source of the foreign object) using the detection results by foreign object detection units 70A-70C will be described later.

The foreign object detection units 70A to 70C may be configured similarly to each other. Each of the foreign object detection units 70A to 70C forms a flow path (hereinafter referred to as a "detection flow path") that distributes the treatment liquid flowing through the supply flow path 29. Each of the foreign object detection units 70A to 70C detects foreign objects in the treatment liquid flowing through the detection flow path after receiving light generated by irradiating the corresponding detection flow path with irradiation light (e.g., laser light). As shown in FIG. 5, each of the foreign object detection units 70A to 70C has, for example, a housing 71, a flow path forming unit 72, an irradiation unit 76, a light receiving unit 78, and a control unit 80.

The housing 71 houses the flow path forming section 72, the irradiation section 76, the light receiving section 78, and the control section 80. The housing 71 may be formed in a rectangular parallelepiped shape. The flow path forming section 72 is a member that forms the above-mentioned detection flow path in the supply flow path 29. The flow path forming section 72 includes, for example, a block body in which the detection flow path 74 is formed. This block body is formed in a rectangular parallelepiped shape and is made of a material that is transparent to laser light used for detecting foreign objects. In the following, for convenience of explanation, the flow path located upstream of the detection flow path 74 formed by the foreign object detection unit in the supply flow path 29 is referred to as the "upstream supply flow path 29a", and the flow path located downstream of the detection flow path 74 is referred to as the "downstream supply flow path 29b".

An inlet 74a and an outlet 74b of the detection flow path 74 are formed on the surface of the block body of the flow path forming part 72 facing one side of the housing 71. An end of the upstream supply flow path 29a located upstream of the detection flow path 74 of the supply flow path 29 is connected to the inlet 74a. An end of the downstream supply flow path 29b located downstream of the detection flow path 74 of the supply flow path 29 is connected to the outlet 74b. The pipes forming the ends of the upstream supply flow path 29a and the downstream supply flow path 29b penetrate the side wall of the housing 71 located near the flow path forming part 72.

With the above configuration, the processing liquid sent out from the supply source 52 flows toward the nozzle 30 through the detection flow path 74 formed by the foreign object detection unit 70C, the detection flow path 74 formed by the foreign object detection unit 70B, and the detection flow path 74 formed by the foreign object detection unit 70A, in that order. Due to the relationship between the amount of processing liquid supplied per time and the piping volume of each section, the processing liquid that has passed through the detection flow path 74 of the foreign object detection unit 70C will reach the detection flow path 74 of the foreign object detection unit 70B if processing liquid is subsequently supplied multiple times. Similarly, the processing liquid that has passed through the detection flow path 74 of the foreign object detection unit 70B will reach the detection flow path 74 of the foreign object detection unit 70A if processing liquid is subsequently supplied multiple times.

The irradiation unit 76 is configured to irradiate the detection flow path 74 with irradiation light for detecting foreign matter in the processing liquid. The irradiation unit 76 includes, for example, a light source that generates laser light as the irradiation light. In one example, the light source generates laser light with a wavelength of about 400 nm to 600 nm and an output of about 600 mW to 1000 mW. The irradiation unit 76 may irradiate the irradiation light toward the detection flow path 74 from below.

The light receiving unit 78 is configured to receive light (emitted light) emitted from the detection flow path 74 in association with the irradiation light from the irradiation unit 76. The light receiving unit 78 is disposed, for example, on the side of the detection flow path 74 (at the same height as the flow path forming unit 72). The light receiving unit 78 may include an optical component (lens) that collects the light emitted from the detection flow path 74, and a light receiving element that generates an electrical signal (hereinafter referred to as a "received light signal") in response to the received light. The light receiving unit 78 receives a portion of the light (scattered light) generated when the irradiation light from the irradiation unit 76 is scattered in the detection flow path 74.

When irradiation light is irradiated into the detection flow path 74 through which the processing liquid flows, scattered light is generated regardless of the presence or absence of foreign matter. If the processing liquid in the detection flow path 74 does not contain foreign matter, most of the irradiation light from the irradiation unit 76 passes through the detection flow path 74. On the other hand, if the processing liquid in the detection flow path 74 contains foreign matter, the degree of scattering of the irradiation light in the detection flow path 74 increases, and the intensity of the light received by the light receiving unit 78 (a portion of the scattered light heading toward the light receiving unit 78) increases compared to when no foreign matter is present. Accordingly, the intensity of the above-mentioned received light signal increases.

The light receiving unit 78 receives the light emitted from the detection flow path 74 and outputs a light receiving signal to the control unit 80. The control unit 80 controls each element included in each of the foreign matter detection units 70A-70C, and determines whether or not a foreign matter is present in the processing liquid based on the light receiving signal received by the light receiving unit 78. Below, the control unit 80 will be described together with the above-mentioned control device 20 that controls the liquid processing unit U1, etc.

(Control System)
The control units 80 of the foreign object detection units 70A, 70B, 70C and the control device 20 constitute a control system 100. That is, the substrate processing system 1 includes the control system 100 including the control device 20 and the control unit 80. An output device 19 may be connected to the control device 20. The output device 19 is a device for outputting information output from the control device 20 to an operator such as a worker. The output device 19 is, for example, a monitor. The monitor may be any device capable of displaying information on a screen, and a specific example thereof is a liquid crystal panel.

The control system 100 is configured to at least perform the following operations: supplying processing liquid to the workpiece W from the nozzle 30; detecting foreign matter contained in the processing liquid at multiple different positions along the supply flow path 29 based on a light reception signal obtained by receiving light emitted from within the detection flow path 74 in response to light irradiation; and estimating a section of the supply flow path 29 in which an event causing the detection of a foreign matter occurred based on the foreign matter detection results at each of the multiple positions.

As shown in Figure 6, the control unit 80 of the control system 100 has, as functional configurations (hereinafter referred to as "functional modules"), for example, a light projection control unit 102, a signal acquisition unit 104, and a foreign object determination unit 106. The processes respectively performed by the light projection control unit 102, the signal acquisition unit 104, and the foreign object determination unit 106 correspond to the processes performed by the control unit 80 (control system 100). Figure 6 shows one control unit 80 out of multiple control units 80 possessed by multiple foreign object detection units 70.

The light projection control unit 102 controls the irradiation unit 76 in the corresponding foreign object detection unit among the foreign object detection units 70A to 70C so that the detection flow path 74 formed by the flow path forming unit 72 is irradiated with irradiation light. The light projection control unit 102 may control the irradiation unit 76 so that the detection flow path 74 is irradiated with irradiation light each time the processing liquid is supplied to the workpiece W to be processed (each time the processing liquid is supplied), in accordance with the supply period. In one example, the light projection control unit 102 causes the irradiation unit 76 to start irradiating the irradiation light in accordance with the timing when the processing liquid starts to be discharged from the nozzle 30 to the workpiece W. Then, the light projection control unit 102 causes the irradiation unit 76 to stop irradiating the irradiation light in accordance with the timing when the processing liquid stops being discharged from the nozzle 30 to the workpiece W.

The signal acquisition unit 104 acquires a light reception signal from the light receiving unit 78, which is obtained by receiving scattered light (emitted light) emitted from the detection flow path 74 in response to the irradiation of the irradiation light in a corresponding foreign object detection unit among the foreign object detection units 70A to 70C. The signal acquisition unit 104 may acquire a light reception signal corresponding to the light received from the detection flow path 74 from the light receiving unit 78 in accordance with the supply period each time the processing liquid is supplied to the workpiece W to be processed (each time the processing liquid is supplied). In one example, the signal acquisition unit 104 acquires a light reception signal from the light receiving unit 78 each time the processing liquid is supplied in accordance with the irradiation timing (irradiation period) of the irradiation light by the light projection control unit 102.

The foreign object determination unit 106 determines the presence or absence of a foreign object in a corresponding foreign object detection unit among the foreign object detection units 70A-70C based on the light receiving signal acquired by the signal acquisition unit 104. In detail, the foreign object determination unit 106 determines whether or not a foreign object is contained in the processing liquid that has passed through the corresponding location based on the light receiving signal acquired by the corresponding foreign object detection unit. The foreign object determination unit 106 may determine the presence or absence of a foreign object in the corresponding location each time processing liquid is supplied.

The foreign matter determination unit 106 may determine the presence or absence of a foreign matter based on an evaluation value obtained by analyzing the change over time in the signal strength of the received light signal. Figure 7 shows an example of the change over time in the signal strength of the received light signal acquired by the signal acquisition unit 104. Figure 7 shows the received light signal acquired during one supply period Ta of the processing liquid, and the signal strength exceeds a predetermined intensity threshold Th1 at times t1, t2, and t3.

The foreign object determination unit 106 may calculate an evaluation value by counting the number of times the signal strength exceeds a predetermined intensity threshold Th1, and then determine whether the evaluation value (count value) exceeds a predetermined evaluation threshold Th2. In one example, the foreign object determination unit 106 may determine that the above-mentioned event has occurred at a location (where the foreign object detection unit is located) when the number of times the signal strength exceeds the intensity threshold Th1 exceeds the evaluation threshold Th2. Note that the foreign object determination unit 106 may calculate the evaluation value in any way and determine the presence or absence of a foreign object in any way, as long as it determines the presence or absence of a foreign object based on the light receiving signal (according to the evaluation value obtained from the light receiving signal).

The control device 20 of the control system 100 has, as functional modules, for example, as shown in Fig. 6, a liquid processing control unit 112, a determination result storage unit 114, a source estimation unit 116, a cause estimation unit 118, and an output unit 122. The processing performed by these functional modules corresponds to the processing performed by the control device 20 (control system 100).

The liquid processing control unit 112 controls the processing liquid supply unit 28 so that the processing liquid is supplied to the workpiece W to be processed. For example, when starting discharge from the nozzle 30, the liquid processing control unit 112 controls the discharge valve 34 to transition from a closed state to an open state while the pump 42 of the liquid delivery unit 40 is replenished with the processing liquid and the processing liquid is pressurized. For example, after starting the supply of the processing liquid, when the above-mentioned supply period Ta set in advance has elapsed, the liquid processing control unit 112 controls the discharge valve 34 to transition from an open state to a closed state in order to stop discharge from the nozzle 30. The processing liquid is supplied to the workpiece W during the supply period Ta, thereby performing one supply of the processing liquid (one supply of the processing liquid to one workpiece W).

The judgment result storage unit 114 stores the foreign object detection results (judgment results) at each of the multiple locations by the foreign object detection units 70A-70C. For example, the judgment result storage unit 114 acquires the judgment results at each of the multiple locations by the foreign object judgment units 106 of the multiple control units 80 for each supply of processing liquid, and stores the judgment results. The judgment result storage unit 114 may store the judgment results by the foreign object judgment units 106 in association with the number of times processing liquid is supplied (the number of workpieces W processed). In this case, the judgment result storage unit 114 stores the number of times processing liquid is supplied and the judgment results by the foreign object judgment units 106 for each of the foreign object detection units 70A-70C in association with each other.

The source estimation unit 116 estimates the section in the supply flow path 29 where the event that caused the detection of the foreign object occurred based on the detection results at multiple locations by the foreign object detection units 70A to 70C. The source estimation unit 116 may identify (estimate) the part that is the source of the foreign object by estimating the section where the event is assumed to have occurred. The source estimation unit 116 may estimate the section where the event is assumed to have occurred (the section where the event is occurring if the generation of the foreign object continues) when a foreign object is detected by the foreign object detection unit 70A arranged at the position closest to the nozzle 30. Below, an example of a method for estimating the section where the event is assumed to have occurred will be described with reference to FIG. 8.

Figure 8 shows a graph representing the transition of the evaluation value for detecting foreign objects versus the number of times of supply for each of the foreign object detection units 70A to 70C. In Figure 8, "70A" indicates the transition of the evaluation value (e.g., the number of times the intensity threshold Th1 described above is exceeded) acquired by the foreign object detection unit 70A. "70B" indicates the transition of the evaluation value acquired by the foreign object detection unit 70B, and "70C" indicates the transition of the evaluation value acquired by the foreign object detection unit 70C. In the example shown in Figure 8, when the number of times the processing liquid is supplied to the workpiece W to be processed is "tc", the evaluation value acquired by the foreign object detection unit 70A exceeds the evaluation threshold Th2. In this case, when the processing liquid is supplied tc times, the control unit 80 of the foreign object detection unit 70A detects a foreign object at the location where the foreign object detection unit 70A is located.

When a foreign object is detected in the foreign object detection unit 70A, the source estimation unit 116 refers to the past judgment results of the presence or absence of a foreign object in the foreign object detection units 70B and 70C. For example, the source estimation unit 116 refers to the judgment results of other detection units at a time point a predetermined number of times back from the number of supplies when the foreign object was detected in the foreign object detection unit 70A. This predetermined number is set so that the judgment result at the time when the foreign object in the processing liquid when the foreign object was detected in the foreign object detection unit 70A is assumed to have passed through the detection flow path 74 of the foreign object detection unit 70B in the past can be referred to. For example, the above-mentioned predetermined number is determined based on the relationship between the amount of discharge in one supply of processing liquid and the piping volume between the foreign object detection unit 70A and the foreign object detection unit 70B.

In the example shown in Figure 8, the predetermined number of times is set to "b", and the source estimation unit 116 refers to the judgment results of the foreign object detection units 70B, 70C when the number of supplies is "tc-b". In this case, the processing liquid that has passed through the detection flow path 74 of the foreign object detection unit 70B when the number of supplies is (tc-b) passes through (reaches) the detection flow path 74 of the foreign object detection unit 70A when the number of supplies is tc.

In one example, if a foreign object has not been detected by both foreign object detection units 70B and 70C at a point in time going back a predetermined number of times, the source estimation unit 116 estimates that the above-mentioned event has occurred in the section between foreign object detection units 70A and 70B. In this case, the source estimation unit 116 may estimate that the discharge valve 34 included in the section of the supply flow path 29 located between foreign object detection units 70A and 70B is the source of the foreign object.

If a foreign object is detected by foreign object detection unit 70B and not detected by foreign object detection unit 70C at a point in time going back a predetermined number of times, the source estimation unit 116 estimates that the above-mentioned event has occurred in the section between foreign object detection unit 70B and foreign object detection unit 70C. In this case, the source estimation unit 116 may estimate that at least one of the pump 42 and the filter 46 included in the section of the supply flow path 29 located between the foreign object detection unit 70B and the foreign object detection unit 70C is the source of the foreign object. FIG. 8 illustrates an example of a determination result in such an estimation.

If a foreign object has been detected by both foreign object detection units 70B and 70C at a point in time going back a predetermined number of times, the source estimation unit 116 estimates that the above-mentioned event has occurred in a section upstream of the foreign object detection unit 70C. In this case, the source estimation unit 116 may estimate that at least one of the supply source 52, the storage tank 56, and the pump 58 included in the section of the supply flow path 29 located upstream of the foreign object detection unit 70C is the source of the foreign object.

In the above example, the source estimation unit 116 may refer to the judgment result for the foreign object detection unit 70C at a predetermined number of times going back from the (tc-b) time, which is determined from the relationship between the discharge amount of processing liquid in one supply and the piping volume between the foreign object detection unit 70B and the foreign object detection unit 70C. As exemplified above, the source estimation unit 116 may estimate which part is the source of the foreign object by estimating the section in which the above event is assumed to have occurred (is occurring).

The factor estimation unit 118 estimates the cause of the occurrence of the above event according to the section estimated by the source estimation unit 116. The cause of the occurrence of the above event is the action or phenomenon that caused the occurrence of the above event. The factor estimation unit 118 estimates the cause of the occurrence of the above event, for example, by referring to a table in which the section in which the above event is estimated to have occurred (the estimated source of the foreign matter) and the cause of the foreign matter occurrence are previously associated. In one example, when the factor estimation unit 118 estimates that the above event has occurred in a section including the pump 42 and the filter 46, it estimates that the replacement of the pump or filter, the retention of the processing liquid, and the change in the operating conditions of the pump are the causes of the occurrence of the above event. In the present disclosure, estimating the cause of the occurrence of the above event does not only mean identifying one cause, but also includes the case of identifying multiple causes (candidate causes).

The output unit 122 outputs information indicating the section estimated by the source estimation unit 116 when a foreign object is detected in the supply flow path 29. The output unit 122 may output information indicating the estimated section to the output device 19 when a foreign object is detected in the foreign object detection unit 70A. In this case, the output device 19 may display information indicating that a foreign object has been detected and the estimated section. The output unit 122 may also output information indicating the cause (candidate cause) of the occurrence of the above-mentioned event estimated by the cause estimation unit 118.

Figure 9 is a block diagram showing an example of the hardware configuration of the control unit 80 and the control device 20. One control unit 80 is composed of one or more computers. For example, the control unit 80 has a circuit 150. The circuit 150 has one or more processors 152, a memory 154, a storage 156, an input/output port 158, a timer 162, and a communication port 164. The storage 156 has a storage medium readable by a computer, such as a hard disk. The storage medium stores a program for causing the control unit 80 to execute the foreign object detection method executed in the foreign object detection units 70A-70C. The storage medium may be a removable medium such as a non-volatile semiconductor memory, a magnetic disk, or an optical disk.

The memory 154 temporarily stores the programs loaded from the storage medium of the storage 156 and the results of calculations by the processor 152. The processor 152 executes the above programs in cooperation with the memory 154 to configure each functional module of the control unit 80. The input/output port 158 inputs and outputs electrical signals between the irradiation unit 76 and the light receiving unit 78, etc., in accordance with instructions from the processor 152. The timer 162 measures the elapsed time, for example, by counting reference pulses at a constant period. The communication port 164 communicates with the control device 20 wirelessly, via a wired line, or via a network line, etc., in accordance with instructions from the processor 152.

When the control unit 80 is composed of multiple computers, each functional module may be realized by a separate computer. Alternatively, each functional module may be realized by a combination of two or more computers. In these cases, the multiple computers may be connected to each other so as to be able to communicate with each other and cooperate to execute the above-mentioned foreign object detection method.

The control device 20 is composed of one or more computers. The control device 20 has, for example, a circuit 170. The circuit 170 has one or more processors 172, a memory 174, a storage 176, an input/output port 178, a timer 182, and a communication port 184. The storage 176 has a storage medium readable by a computer, such as a hard disk. The storage medium stores a program for causing the coating and developing apparatus 2 to execute the substrate processing method described below. The storage medium may be a removable medium such as a non-volatile semiconductor memory, a magnetic disk, or an optical disk.

The memory 174 temporarily stores the programs loaded from the storage medium of the storage 176 and the results of calculations by the processor 172. The processor 172 executes the above programs in cooperation with the memory 174 to configure each functional module of the control device 20. The input/output port 178 inputs and outputs electrical signals between the processing liquid supply unit 28 and the output device 19, etc., in accordance with instructions from the processor 172. The timer 182 measures the elapsed time, for example, by counting reference pulses at a constant period. The communication port 184 communicates with the control unit 80 (the above-mentioned communication port 164) wirelessly, via a wired line, or via a network line, etc., in accordance with instructions from the processor 172.

When the control device 20 is composed of multiple computers, each functional module may be realized by a separate computer. Alternatively, each functional module may be realized by a combination of two or more computers. In these cases, the multiple computers may be connected to each other so as to be able to communicate with each other and cooperate to execute the substrate processing method described below.

The hardware configuration of the control unit 80 and the control device 20 is not necessarily limited to configuring each functional module by a program. For example, each functional module of the control unit 80 and the control device 20 may be configured by a dedicated logic circuit or an ASIC (Application Specific Integrated Circuit) that integrates the dedicated logic circuit.

(Substrate Processing Method)
Next, a series of processes executed by a control system 100 including a control unit 80 and a control device 20 will be described as an example of a substrate processing method including foreign matter detection with reference to Fig. 10. Fig. 10 is a flow chart showing a series of processes executed in response to the supply of processing liquid to one workpiece W.

In this series of processes, the control system 100 executes step S11 after the supply (discharge) of processing liquid to the workpiece W to be processed has begun and the irradiation of light to the detection flow path 74 in each foreign object detection unit and the generation of a light reception signal by the light receiving unit 78 have begun. In step S11, for example, the control unit 80 waits until the supply of processing liquid to the workpiece W to be processed is completed. Until the supply of processing liquid is completed, the signal acquisition unit 104 of the control unit 80 in each foreign object detection unit continues to acquire the light reception signal.

Next, the control system 100 executes step S12. In step S12, for example, the foreign matter determination section 106 of the control section 80 in each foreign matter detection unit determines whether or not a foreign matter has occurred in the processing liquid. In one example, the foreign matter determination section 106 calculates an evaluation value (for example, the number of times the signal strength exceeds an intensity threshold value Th1) from the light receiving signal obtained during the period in which the supply of the processing liquid continues, and compares the evaluation value with an evaluation threshold value Th2 to determine whether or not a foreign matter has occurred in the processing liquid.

Next, the control system 100 executes step S13. In step S13, for example, the judgment result accumulation unit 114 of the control device 20 accumulates (stores) the judgment results in step S12 for each foreign object detection unit. The judgment result accumulation unit 114 may accumulate the number of times the processing liquid is supplied (the number of processed workpieces W) and the judgment results by each foreign object detection unit in association with each other.

Next, the control system 100 executes step S14. In step S14, for example, the source estimation unit 116 of the control device 20 determines whether or not a foreign object was detected in step S12 for the foreign object detection unit (in the above example, foreign object detection unit 70A) located at the most downstream position among the multiple foreign object detection units provided in the supply flow path 29.

If it is determined in step S14 that a foreign object has been detected in the foreign object detection unit located at the most downstream position (step S14: YES), the control system 100 executes step S15. In step S15, for example, the source estimation unit 116 refers to past determination results regarding the presence or absence of a foreign object in foreign object detection units other than the foreign object detection unit located at the most downstream position, and estimates the section in the supply flow path 29 in which an event causing the detection of a foreign object has occurred. In one example, the source estimation unit 116 estimates the above-mentioned section by referring to the determination results of the number of times that the processing liquid that passed through the foreign object detection unit located at the most downstream position during the execution of step S11 has passed through other foreign object detection units (in the above example, foreign object detection units 70B and 70C) in the past.

Next, the control system 100 executes step S16. In step S16, for example, the factor estimation unit 118 of the control device 20 estimates a factor (candidate factor) of the occurrence of the above event according to the section estimated in step S15. In one example, the factor estimation unit 118 estimates the factor of the occurrence of the above event by referring to a table in which sections and factors of the occurrence of the above event are previously associated with each other.

Next, the control system 100 executes step S17. In step S17, for example, the output unit 122 of the control device 20 outputs to the output device 19 information indicating that a foreign object has been detected and the partition estimated in step S15. The output unit 122 may also output to the output device 19 information indicating the cause estimated in step S16. After the information is output from the output unit 122, a procedure for removing the foreign object may be performed in the processing liquid supply unit 28 in accordance with an instruction from an operator or the like in response to the information output to the output device 19.

On the other hand, in step S14, if it is determined that no foreign object is detected by the foreign object detection unit located at the most downstream position (step S14: NO), the control system 100 does not execute steps S15 to S17. The control system 100 may repeat the series of processes of steps S11 to S17 (S14) each time the control system 100 supplies processing liquid to each of the subsequent multiple workpieces W.

(Modification)
The above-described series of processes is an example and can be modified as appropriate. In the above-described series of processes, the control system 100 may execute one step and the next step in parallel, or may execute each step in an order different from the above-described example. The control system 100 may omit any step, or may execute a process different from the above-described example in any step.

The method of estimating the section in which the event causing the foreign object detection is assumed to have occurred is not limited to the above example. In the above example, the section is estimated when a foreign object is detected in the foreign object detection unit located at the most downstream position, but the source estimation unit 116 may estimate the section (the source of the foreign object) when a foreign object is detected in any of the foreign object detection units. For example, when a foreign object is detected in any of the foreign object detection units, the source estimation unit 116 estimates that the above event has occurred in a section located adjacent to the foreign object detection unit upstream.

In one example, the source estimation unit 116 estimates that the above event occurred in a section including the supply source 52, the storage tank 56, and the pump 58 included in the refill unit 50 when a foreign object is detected in the foreign object detection unit 70C. The source estimation unit 116 estimates that the above event occurred in a section including the pump 42 and the filter 46 included in the liquid delivery unit 40 when a foreign object is detected in the foreign object detection unit 70B. When the above event occurs in the refill unit 50, a foreign object may also be detected in the foreign object detection unit 70B as the number of supplies accumulates. In this case, since a foreign object has already been detected in the foreign object detection unit 70C, it is possible to estimate the section including the source of the foreign object. The source estimation unit 116 estimates that the above event occurred in a section including the discharge valve 34 when a foreign object is detected in the foreign object detection unit 70A.

The factor estimation unit 118 may narrow down the cause of the occurrence of the above-mentioned event using other information in addition to the detection results by each foreign matter detection unit. The coating and developing apparatus 2 may further include a flow rate measurement unit 60 as shown in FIG. 4. The flow rate measurement unit 60 measures the flow rate (e.g., the amount of liquid passing per unit time) of the processing liquid flowing through the flow path that leads the processing liquid to the nozzle 30. The flow rate measurement unit 60 may measure the flow rate of the processing liquid by any method. In the example shown in FIG. 4, the flow rate measurement unit 60 is provided in the flow path between the discharge valve 34 and the foreign matter detection unit 70B in the supply flow path 29.

Figure 11 shows an example of the change in flow rate over time measured by the flow rate measurement unit 60. Each pulse in the graph shown in Figure 11 corresponds to one supply of treatment liquid. When no bubbles are contained in the treatment liquid passing through the flow rate measurement unit 60, the change in flow rate over time during the period in which the treatment liquid is continuously supplied is approximately constant. On the other hand, when bubbles are contained in the treatment liquid passing through the flow rate measurement unit 60, the flow rate fluctuates during the period in which the treatment liquid is continuously supplied, as shown in the enlarged graph in Figure 11. The pulses shown enlarged in Figure 11 are the measured values detected when the treatment liquid that has passed through the foreign matter detection unit 70B (tc-b) times as illustrated in Figure 8 passes through the flow rate measurement unit 60. From the above, it is possible to estimate whether or not the treatment liquid containing bubbles contains foreign matter by detecting the change in flow rate when the treatment liquid containing bubbles passes through the flow rate measurement unit 60.

The factor estimation unit 118 may narrow down the cause of the occurrence of the above-mentioned event based on the measurement result by the flow rate measurement unit 60. For example, when the factor estimation unit 118 estimates that a part in the liquid delivery unit 40 is the source of the foreign matter, the factor estimation unit 118 may narrow down the cause of the occurrence of the above-mentioned event according to the degree of fluctuation in the flow rate measured by the flow rate measurement unit 60 when the processing liquid passes through the flow rate measurement unit 60 after passing through the foreign matter detection unit 70B. In one example, when the fluctuation in the flow rate is greater than a predetermined level, the factor estimation unit 118 narrows down the cause of the occurrence of the above-mentioned event (candidates for the cause) to the generation of bubbles due to replacement of the pump or filter, the generation of bubbles due to the retention of the processing liquid, and the generation of bubbles due to changes in the operating conditions of the pump. In this case, measures such as removing bubbles from around the pump or filter may be taken based on instructions from an operator or the like. The factor estimation unit 118 may estimate that the generation of bubbles is not the cause when the fluctuation in the flow rate is smaller than a predetermined level. The measurement result by the flow rate measurement unit 60 may be used to check whether the flow rate is stable each time the processing liquid is supplied.

The information used to narrow down the causes of the occurrence of the above-mentioned event is not limited to the above-mentioned fluctuation in flow rate. The cause estimation unit 118 may narrow down the causes of the occurrence of the above-mentioned event based on the supply frequency (discharge frequency) of the processing liquid to the workpiece W when the foreign object is detected. If the supply frequency of the processing liquid is low within a specified period immediately prior to and including the time when the foreign object is detected, it can be estimated that the processing liquid is stagnating in the supply flow path 29. The cause estimation unit 118 may narrow down the causes of the occurrence of the above-mentioned event according to the supply frequency within a specified period immediately prior to and including the time when the foreign object is detected.

For example, when the factor estimation unit 118 estimates that a component in the liquid delivery unit 40 is the source of the foreign matter, the factor estimation unit 118 may narrow down the cause of the occurrence of the above-mentioned event according to the supply frequency within the above-mentioned specified period including the time point at which the foreign matter was detected by the foreign matter detection unit 70B. In one example, when the supply frequency within the above-mentioned specified period is smaller than a predetermined threshold, the factor estimation unit 118 may narrow down the cause of the occurrence of the above-mentioned event to stagnation of processing liquid. When the supply frequency within the above-mentioned specified period is greater than a predetermined threshold, the factor estimation unit 118 may narrow down the cause of the occurrence of the above-mentioned event to replacement of the pump or filter and a change in the operating conditions of the pump.

In the above example, the liquid processing unit U1 has one processing liquid supply unit 28, but may have multiple processing liquid supply units 28. In this case, the liquid processing unit U1 has multiple nozzles 30 and multiple supply flow paths 29 for supplying processing liquid to each of the multiple nozzles 30. The foreign matter detection units 70A-70C may detect foreign matter at multiple locations for each of the multiple supply flow paths 29. The control system 100 may estimate the section in which the above-mentioned event is assumed to have occurred (the section assumed to include the source of the foreign matter) in each of the multiple supply flow paths 29.

A single foreign object detection unit may have a member for detecting foreign objects at multiple different positions along a single supply flow path 29. For example, a single foreign object detection unit may have multiple flow path forming parts 72 that respectively form a detection flow path 74 located between the nozzle 30 and the discharge valve 34, a detection flow path 74 located between the discharge valve 34 and the liquid delivery section 40, and a detection flow path 74 located between the liquid delivery section 40 and the refill section 50. The foreign object detection unit may also have multiple irradiation parts 76 and multiple light receiving parts 78 corresponding to these detection flow paths 74. In this case, a single foreign object detection unit has multiple foreign object detection parts that detect foreign objects in multiple detection flow paths 74 provided at multiple positions on the supply flow path 29.

The coating and developing apparatus 2 may have two foreign object detection units that detect foreign objects at different positions on the supply flow path 29, or may have four or more foreign object detection units. The arrangement of the multiple foreign object detection units (foreign object detection units 70A to 70C) is not limited to the above example, and may be any location as long as they are different positions on the supply flow path 29. The parts that may be the source of foreign objects are not limited to the above example, and may include, for example, a valve that opens and closes the flow path at a position different from the discharge valve 34, and a tube that forms the flow path of the processing liquid. The liquid delivery section 40 is not limited to the above example, and may be configured in any way as long as it has a filter and a pump. The refilling section 50 is not limited to the above example, and may be configured in any way as long as it can refill the liquid delivery section 40 with processing liquid.

The control device 20 may have a functional module that determines the presence or absence of a foreign object at each of multiple locations on the supply flow path 29. In this case, the control unit 80 may not have a foreign object determination unit 106. The control unit 80 of any one of the foreign object detection units 70A-70C may have a functional module that estimates the section in which the above-mentioned event is assumed to have occurred, a functional module that estimates the cause of the foreign object occurrence, and a functional module that outputs the estimation result. In this case, the control units 80 of the foreign object detection units 70A-70C may be connected to each other so that they can communicate with each other, and the control device 20 may not have some of the above-mentioned functional modules.

(Effects of the embodiment)
The substrate processing system 1 according to the first embodiment described above includes a processing liquid supply unit 28 having a nozzle 30 capable of ejecting a processing liquid, a processing liquid supply source 52, and a supply flow path 29 connecting the nozzle 30 and the supply source 52, and supplying the processing liquid to the workpiece W, a plurality of foreign object detection units (foreign object detection units 70A-70C) arranged at different positions along the supply flow path 29 and detecting foreign objects contained in the processing liquid based on a light reception signal obtained by receiving light emitted from within the supply flow path 29 in response to light irradiation, and a source estimation unit 116 which estimates a section of the supply flow path 29 in which an event causing the detection of a foreign object occurred, based on the detection results at each of the plurality of positions by the plurality of foreign object detection units.

Unlike the above example, in order to prevent the supply of processing liquid containing foreign matter to the workpiece W, a method is considered in which a foreign matter detection unit is disposed at one location between the nozzle and the discharge valve in the supply flow path between the nozzle and the processing liquid source to detect foreign matter in the processing liquid. With this method, it is possible to know that a foreign matter has occurred in the processing liquid, but it is not possible to know from the detection result what factor caused the above-mentioned event upstream of the foreign matter detection unit. In contrast, in the substrate processing system 1, the section in which the above-mentioned event occurred is estimated from the detection result of foreign matter at multiple locations on the supply flow path 29. Therefore, by using the estimation result, it is possible to easily know the factor causing the above-mentioned event in the processing liquid supply unit 28.

The treatment liquid supply unit 28 may have a liquid delivery unit 40 including a filter 46 that collects foreign matter contained in the treatment liquid in the supply flow path 29 and a pump 42 that delivers the treatment liquid toward the nozzle 30, and a discharge valve 34 that opens and closes the flow path between the liquid delivery unit 40 and the nozzle 30 in the supply flow path 29. The multiple foreign matter detection units may have a first foreign matter detection unit (foreign matter detection unit 70A) arranged in the flow path between the nozzle 30 and the discharge valve 34, and a second foreign matter detection unit (foreign matter detection unit 70B) arranged in the flow path between the discharge valve 34 and the liquid delivery unit 40. In this case, it is possible to estimate, from the detection results by the first foreign matter detection unit and the second foreign matter detection unit, whether the section in which the above-mentioned event is assumed to have occurred is a section including the discharge valve 34 or a section including the pump 42 and filter 46 of the liquid delivery unit 40.

The processing liquid supply unit 28 may further include a refill unit 50 that refills the processing liquid from a supply source 52 to the liquid delivery unit 40. The multiple foreign object detection units may further include a third foreign object detection unit (foreign object detection unit 70C) disposed in the flow path between the refill unit 50 and the liquid delivery unit 40. In this case, by also using the detection result by the third foreign object detection unit, it is possible to estimate that the section in which the above-mentioned event is assumed to have occurred in the section not including the discharge valve 34 (the section upstream of the second foreign object detection unit) is either the section including the liquid delivery unit 40 or the section including the refill unit 50.

The substrate processing system 1 may further include a factor estimation unit 118 that estimates the cause of the occurrence of the above-mentioned event according to the section estimated by the source estimation unit 116. In this case, by using the result of the factor estimation by the factor estimation unit 118, it becomes possible to more easily grasp the cause of the occurrence of the above-mentioned event.

The substrate processing system 1 may further include a flow rate measurement unit 60 that measures the flow rate of the processing liquid flowing through a flow path that guides the processing liquid to the nozzle 30. The cause estimation unit 118 may narrow down the causes of the occurrence of the above-mentioned event based on the measurement results by the flow rate measurement unit 60. In this case, since the estimation results of the causes of the occurrence of the above-mentioned event are narrowed down, it becomes possible to more easily grasp the causes of the occurrence of the above-mentioned event.

The cause estimation unit 118 may narrow down the causes of the occurrence of the above-mentioned event based on the frequency of supply of the processing liquid to the workpiece W when the above-mentioned event occurs. In this case, since the estimation results of the causes of the occurrence of the above-mentioned event are narrowed down, it becomes possible to more easily grasp the causes of the occurrence of the above-mentioned event.

[Second embodiment]
Next, the substrate processing system 1 according to the second embodiment will be described with reference to Figs. 12 and 13. The substrate processing system 1 according to the second embodiment is configured similarly to the substrate processing system 1 according to the first embodiment. In the substrate processing system 1 according to the second embodiment, other chemicals mixed in the processing liquid are detected as foreign matter instead of the above-mentioned particles such as dust, dirt, and bubbles. That is, in the present disclosure, the "foreign matter" in the processing liquid includes not only the above-mentioned particles such as dust, dirt, and bubbles, but also chemicals having components different from the processing liquid. In the substrate processing system 1 according to the first embodiment, particles and the like are detected based on an evaluation value, whereas the substrate processing system 1 according to the second embodiment uses the intensity of background light to detect other chemicals in the processing liquid.

Background light is light that is emitted (e.g., scattered) from the detection flow path 74 when light is irradiated onto the processing liquid, regardless of the presence or absence of particles. As shown in FIG. 7, the degree of scattering of the irradiated light in the detection flow path 74 (in the processing liquid) changes depending on the presence or absence of particles such as dust, so the magnitude of the signal intensity changes depending on the presence or absence of particles. The received signal corresponding to the scattered light includes a signal Ib corresponding to the background light when no particles are present, and a signal Is corresponding to the scattered light from the particle when the particle is present. In more detail, the signal Is is a signal corresponding to the background light and the scattered light scattered by the particle.

The signal Ib corresponding to the background light may include a component corresponding to scattered light from a substance normally contained in the processing liquid and a component corresponding to disturbance. An example of a substance normally contained in the processing liquid is a base resin (base polymer). The foreign object detection unit 70 obtains the intensity of the background light contained in the light emitted from the detection flow path 74 from the above-mentioned light receiving signal. The foreign object detection unit 70 detects other chemical liquids mixed in the processing liquid as foreign objects by utilizing the fact that the intensity of the background light changes depending on the type of chemical liquid such as the processing liquid. The following illustrates an example in which the liquid processing unit U1 of the processing module 12 supplies a processing liquid (hereinafter referred to as "processing liquid Lr") for forming a resist film to the workpiece W.

In the supply flow path 29, other chemical liquids may be mixed into the processing liquid Lr. The other chemical liquid is, for example, the cleaning liquid Lc. FIG. 12 shows the measurement results of the intensity of the background light when the processing liquid Lr and the cleaning liquid Lc are supplied. In FIG. 12, the vertical axis shows the intensity of the background light [mW]. The intensity of the background light is obtained by calculating the time average of the intensity in a predetermined period in the received light signal. From the graph shown in FIG. 12, it can be seen that the intensity of the background light differs depending on the type of chemical liquid. Specifically, it can be seen that the intensity of the background light differs between the case where the processing liquid Lr is supplied and the case where the cleaning liquid Lc is supplied. It can also be seen that the intensity of the background light has an approximately constant level if the type of chemical liquid is the same.

When replacement of the chemical liquid occurs in the supply flow path 29, other chemical liquids may become mixed into the processing liquid Lr. The liquid processing unit U1 continues to supply processing liquid Lr to each workpiece W while processing of the workpiece W continues in the coating and developing apparatus 2. While processing of the workpiece W continues, the processing may be interrupted and maintenance performed on the liquid processing unit U1. One example of maintenance is replacement of parts such as the filter 46 included in the processing liquid supply section 28.

When maintenance is performed, the processing liquid Lr in the supply flow path 29 is replaced with cleaning liquid Lc. Then, when processing is resumed after maintenance is completed, the processing liquid Lr is replaced again in the supply flow path 29. For example, if the replacement of the cleaning liquid Lc with the processing liquid Lr is not sufficiently performed when processing is resumed, some of the cleaning liquid Lc may become mixed with the processing liquid Lr during processing of the workpiece W.

In the graph shown in FIG. 12, the horizontal axis indicates the number of supplies. After the supply of the processing liquid Lr continues, when the supply count is "tc1", the processing liquid Lr is replaced with the cleaning liquid Lc, and when the supply count is "tc2", the processing liquid Lr is replaced again. The reason why the intensity of the background light is not stable in the period immediately after tc1 and tc2 is thought to be because the processing liquid Lr and the cleaning liquid Lc are mixed and the replacement of the chemical liquid is not complete. By utilizing the characteristic that the intensity of the background light depends on the type of chemical liquid, the intensity of the background light can be measured after the replacement of the chemical liquid is completed (after the number of supplies at which the replacement is assumed to be complete), and thus insufficient replacement of the chemical liquid can be detected.

The control device 20 and the control unit 80 execute the same process as the series of processes shown in FIG. 10. In step S12, each of the multiple foreign object detection units 70A-70C determines whether or not the treatment liquid Lr contains a foreign object based on intensity information indicating the intensity of background light contained in the light (e.g., scattered light) emitted from the supply flow path 29. In one example, the foreign object determination unit 106 of the control unit 80 possessed by each foreign object detection unit acquires intensity information indicating the intensity of background light contained in the scattered light in the corresponding detection flow path 74 from the received light signal (calculates the intensity of the background light). The foreign object determination unit 106 determines whether the intensity of the background light indicated by the intensity information is at a level corresponding to the treatment liquid Lr.

When the intensity of the background light is outside a predetermined level (predetermined range) corresponding to the treatment liquid Lr, the foreign matter determination unit 106 determines that the cleaning liquid Lc is mixed in as a foreign matter in the corresponding detection flow path 74. When the treatment liquid Lr is replaced with the cleaning liquid Lc, the foreign matter determination unit 106 may acquire a signal indicating that the replacement is completed throughout the entire supply flow path 29 based on an input from another control device or a user input. The foreign matter determination unit 106 may perform detection of foreign matter based on the background light in the number of supplies after acquiring a signal indicating that the replacement is completed throughout the entire supply flow path 29. For example, the replacement may be determined to be completed when the chemical liquid is discharged from the nozzle 30 a predetermined number of times after the liquid source (bottle) of the chemical liquid is replaced.

The source estimation unit 116 estimates the section in the supply flow path 29 where the event of mixing with cleaning liquid Lc has occurred based on the detection results using the background light intensity information at each of multiple locations by the foreign object detection units 70A to 70C. The source estimation unit 116 may estimate the section where the mixing with cleaning liquid Lc has occurred (the section where the event that caused the detection of a foreign object has occurred) when the mixing with cleaning liquid Lc is detected by the foreign object detection unit 70A arranged at the position closest to the nozzle 30. Below, an example of a method for estimating the section where the mixing with cleaning liquid Lc is assumed to have occurred will be described with reference to FIG. 13.

Figure 13 shows a graph representing the change in background light intensity over time for each of foreign object detection units 70A to 70C versus the number of times the light is supplied. In Figure 13, "70A" shows the change in background light intensity over time acquired by foreign object detection unit 70A. "70B" shows the change in background light intensity over time acquired by foreign object detection unit 70B, and "70C" shows the change in background light intensity over time acquired by foreign object detection unit 70C.

"TLv" is the level (range) of the intensity of the background light when the detection flow path 74 is filled with the cleaning liquid Lc. "RLv" is the level (range) of the intensity of the background light when the detection flow path 74 is filled with the treatment liquid Lr. The intensity levels TLv, RLv of the background light corresponding to the cleaning liquid Lc or the treatment liquid Lr are measured in advance. In the example shown in FIG. 13, the replacement of the cleaning liquid Lc with the treatment liquid Lr is started when the number of times the chemical solution of the cleaning liquid Lc or the treatment liquid Lr has been supplied is "tc2". After the replacement of the cleaning liquid Lc with the treatment liquid Lr is started, the measured value of the intensity of the background light changes from the intensity level TLv corresponding to the cleaning liquid Lc to the intensity level RLv corresponding to the treatment liquid Lr, starting from the upstream.

When the number of chemical liquid supplies reaches "ts", the foreign matter detection unit 70A determines that the intensity of the background light is outside the intensity level RLv corresponding to the processing liquid Lr, and that the processing liquid Lr is mixed with cleaning liquid Lc. When the number of supplies reaches ts, the control unit 80 (foreign matter determination unit 106) acquires a signal indicating that replacement is complete. If the foreign matter detection unit 70A does not have any mixing of cleaning liquid Lc, the intensity of the background light would have reached the intensity level RLv corresponding to the processing liquid Lr at the time of ts, as shown by the dotted line in the graph.

When the foreign object detection unit 70A detects the presence of cleaning liquid Lc, the source estimation unit 116 refers to the past judgment results of the foreign object detection units 70B and 70C regarding the presence or absence of foreign objects. For example, the source estimation unit 116 refers to the judgment results of other detection units at a time point a predetermined number of times ("b" times) back from the ts time point. This predetermined number of times is set so that the judgment results at the time point when the cleaning liquid Lc in the processing liquid detected by the foreign object detection unit 70A is assumed to have passed through the detection flow path 74 of the foreign object detection unit 70B in the past can be referenced, as in the example shown in FIG. 8.

In one example, if neither foreign object detection unit 70B, 70C has detected the presence of cleaning liquid Lc at a predetermined number of times going back ("ts-b" times), the source estimation unit 116 estimates that the presence of cleaning liquid Lc is occurring (has occurred) in the section between foreign object detection unit 70A and foreign object detection unit 70B. If the presence of cleaning liquid Lc is detected by foreign object detection unit 70B at the (ts-b) time point, and the presence of cleaning liquid Lc is not detected by foreign object detection unit 70C, the source estimation unit 116 estimates that the presence of cleaning liquid Lc is occurring (has occurred) in the section between foreign object detection unit 70B and foreign object detection unit 70C. Figure 13 illustrates the judgment result when this estimation is made.

If the presence of cleaning liquid Lc is detected by both foreign object detection units 70B and 70C at a time point going back a predetermined number of times, the source estimation unit 116 estimates that the presence of cleaning liquid Lc is occurring (occurred) in a section upstream of the foreign object detection unit 70C. The cause estimation unit 118 estimates the cause of the occurrence of the above-mentioned event based on the detection result based on the intensity of background light by the foreign object determination unit 106 and the section estimated by the source estimation unit 116. When the determination result of the example shown in FIG. 13 is obtained, the source estimation unit 116 may estimate that insufficient replacement of the chemical solution in the filter 46 or the pump 42 is the cause of the event that causes the detection of a foreign object.

The following are some of the events that may cause the chemicals to become mixed in the filter 46. The cleaning liquid Lc that was passed through the piping of the supply flow path 29 to clean it before the start of processing using the processing liquid Lr may remain in a narrow area inside the filter 46 (such as an internal flow path of a material that collects foreign matter, not shown), and the remaining cleaning liquid Lc may not be discharged. In this case, the processing liquid Lr fills the piping of the supply flow path 29 without a portion of the cleaning liquid Lc being discharged. Since the pressure loss is likely to be higher in the narrow area inside the filter 46 than in other flow paths in the supply flow path 29, the processing liquid Lr is not immediately dissolved when filled, and the cleaning liquid Lc may dissolve at an unexpected timing during pressure control for liquid delivery during actual processing.

The example shown in the first embodiment may be applied to the substrate processing system 1 according to the second embodiment. The foreign matter detection unit 70 may detect particles based on an evaluation value obtained from the light receiving signal, and detect the presence of other chemical liquids based on intensity information indicating the intensity of background light. In detection based on the evaluation value, foreign matter is detected based on fluctuations in the instantaneous value of the light receiving signal, whereas in detection based on the intensity information, foreign matter is detected based on the time-averaged magnitude of the entire light receiving signal. When a foreign matter is detected in at least one of detection based on the evaluation value and detection based on the intensity information, the foreign matter detection unit 70 may determine that a foreign matter is contained in the processing liquid in the corresponding detection flow path 74.

When a foreign object is detected in detection based on the intensity information, the factor estimation unit 118 may narrow down the causes of the occurrence of the above-mentioned event based on the measurement results of the flow velocity of the processing liquid flowing through the supply flow path 29, as in the above-mentioned example. When a foreign object is detected in detection based on the intensity information, the factor estimation unit 118 may narrow down the causes of the occurrence of the above-mentioned event based on the frequency of supply of the processing liquid to the workpiece W when the above-mentioned event occurred, as in the above-mentioned example.

When a foreign object is detected in the detection based on the intensity information, a procedure for discharging the other chemical liquid (cleaning liquid Lc) may be performed based on the instructions of an operator, etc. In one example of a procedure for discharging the other chemical liquid, the flow state of the processing liquid Lr is maintained until the intensity of the background light reaches an intensity level corresponding to the processing liquid (processing liquid Lr). In this procedure, dummy discharge on a standby bath capable of discharging the liquid may be repeatedly performed with the continuous pressurization time being shorter than when the processing liquid Lr is actually supplied to the workpiece W. Increasing the frequency of pressure fluctuations in this manner can encourage the stagnant cleaning liquid Lc to dissolve into the processing liquid Lr.

There are cases where detection of foreign matter caused by the generation of bubbles and detection of foreign matter caused by insufficient replacement of the chemical solution occur at approximately the same time. For example, detection based on the evaluation value and detection based on the intensity information between the liquid delivery unit 40 and the discharge valve 34 may lead to estimation that foreign matter has occurred in the treatment liquid at approximately the same time. In this case, the factor estimation unit 118 may estimate that there are two factors: the presence of bubbles in the filter 46 or pump 42, and the retention of other chemical solution in the filter 46.

When two factors are estimated, the dummy discharge may be continued until the intensity of the background light reaches an intensity level corresponding to the processing liquid. When the intensity of the background light stabilizes first in a state where bubbles are present, the frequency of switching between increasing and decreasing the pressure during the dummy discharge may be reduced from the state in which the dummy discharge was performed intermittently, thereby suppressing the risk of an increase in microbubbles due to vibration and further promoting the reduction of bubbles. In this way, when the factor estimation unit 118 (controller 20) estimates multiple events that cause the detection of foreign matter, it may monitor the progress of each subsequent event as the treatment operation such as dummy discharge or other operation in the substrate processing system 1 progresses after the estimation. For example, the factor estimation unit 118 may sequentially determine which of the multiple events has stabilized, that is, which event's influence has been eliminated, based on the light reception signals in the foreign matter detection units 70A to 70C. The factor estimation unit 118 (controller 20) sequentially determines the stability of the events and determines the necessary treatment operation according to the event that is not yet stable at a certain point in time, thereby enabling efficient stabilization when multiple events occur.

In the substrate processing system 1 according to the second embodiment described above, as in the first embodiment, it is possible to easily grasp the cause of an event that causes detection of a foreign object in the processing liquid supply unit 28. Furthermore, by detecting another chemical liquid in the processing liquid as a foreign object based on intensity information indicating the intensity of background light contained in the emitted light, it is possible to easily detect insufficient replacement of a chemical liquid such as the processing liquid.

1...substrate processing system, 2...coating and developing apparatus, 20...control device, U1...liquid processing unit, 28...processing liquid supply section, 29...supply flow path, 30...nozzle, 34...discharge valve, 40...liquid delivery section, 42...pump, 46...filter, 50...replenishment section, 52...supply source, 60...flow rate measurement section, 70, 70A, 70B, 70C...foreign matter detection unit, 116...source estimation section, 118...cause estimation section, W...work.

Claims (8)

a processing liquid supply unit including a nozzle capable of discharging a processing liquid, a supply source of the processing liquid, and a supply flow path connecting the nozzle and the supply source, and supplying the processing liquid to a substrate;
a plurality of foreign matter detectors that are arranged at different positions along the supply flow path and detect foreign matter contained in the treatment liquid based on a light reception signal obtained by receiving light emitted from within the supply flow path in response to irradiation with light;
a source estimation unit that estimates a section in the supply flow path where an event that caused the detection of the foreign object occurred based on detection results at the plurality of locations by the plurality of foreign object detection units; and
a cause estimation unit that estimates a cause of the occurrence of the event according to the section estimated by the occurrence source estimation unit;
a flow rate measuring unit that measures a flow rate of the treatment liquid flowing through a flow path that guides the treatment liquid to the nozzle,
The cause estimating unit narrows down causes of occurrence of the event based on a measurement result by the flow velocity measuring unit. a processing liquid supply unit including a nozzle capable of discharging a processing liquid, a supply source of the processing liquid, and a supply flow path connecting the nozzle and the supply source, and supplying the processing liquid to a substrate;
a plurality of foreign matter detectors that are arranged at different positions along the supply flow path and detect foreign matter contained in the treatment liquid based on a light reception signal obtained by receiving light emitted from within the supply flow path in response to irradiation with light;
a source estimation unit that estimates a section in the supply flow path where an event that caused the detection of the foreign object occurred based on detection results at the plurality of locations by the plurality of foreign object detection units; and
a cause estimation unit that estimates a cause of the occurrence of the event according to the section estimated by the occurrence source estimation unit,
The cause estimating unit narrows down causes of occurrence of the event based on a frequency of supply of the processing liquid to the substrate when the event occurs. The processing liquid supply unit includes:
a liquid delivery unit including a filter that collects foreign matter contained in the treatment liquid in the supply flow path and a pump that delivers the treatment liquid toward the nozzle;
a discharge valve that opens and closes a flow path between the liquid delivery unit and the nozzle in the supply flow path;
a replenishing unit that replenishes the treatment liquid from the supply source to the liquid delivery unit,
The plurality of foreign object detection units include
a first foreign object detector disposed in a flow path between the nozzle and the discharge valve;
a second foreign object detector disposed in a flow path between the discharge valve and the liquid delivery unit;
The substrate processing apparatus according to claim 1 , further comprising: a third foreign matter detector disposed in the flow path between the refill unit and the liquid delivery unit. a flow rate measuring unit for measuring a flow rate of the treatment liquid flowing through a flow path that guides the treatment liquid to the nozzle;
The substrate processing apparatus according to claim 2 , wherein the cause estimating unit narrows down causes of the occurrence of the event based on a measurement result by the flow velocity measuring unit. 5. The substrate processing apparatus according to claim 1 , wherein each of the plurality of foreign matter detection units detects another chemical liquid contained in the processing liquid as the foreign matter based on intensity information indicating an intensity of background light contained in the emitted light. supplying a processing liquid onto a substrate from a nozzle capable of discharging the processing liquid;
detecting foreign matter contained in the treatment liquid based on a light receiving signal obtained by receiving light emitted from within the supply flow path in response to irradiation of light at a plurality of different positions along the supply flow path connecting a supply source of the treatment liquid and the nozzle;
estimating a section in the supply flow path in which an event that caused the detection of the foreign object occurred based on a result of the detection of the foreign object at each of the plurality of locations;
estimating a cause of the occurrence of the event according to the section in which the event is estimated to have occurred;
measuring a flow rate of the treatment liquid flowing through a flow path that guides the treatment liquid to the nozzle;
In the step of estimating the cause, causes of the occurrence of the event are narrowed down based on a result of measuring the flow velocity . supplying a processing liquid onto a substrate from a nozzle capable of discharging the processing liquid;
detecting foreign matter contained in the treatment liquid based on a light receiving signal obtained by receiving light emitted from within the supply flow path in response to irradiation of light at a plurality of different positions along the supply flow path connecting a supply source of the treatment liquid and the nozzle;
estimating a section in the supply flow path in which an event that caused the detection of the foreign object occurred based on a result of the detection of the foreign object at each of the plurality of locations;
and estimating a cause of the occurrence of the event according to the section in which the event is estimated to have occurred;
In the step of estimating the cause, causes of the occurrence of the event are narrowed down based on a frequency of supply of the processing liquid to the substrate when the event occurs. 8. A computer-readable storage medium storing a program for causing an apparatus to execute the substrate processing method according to claim 6 .

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