Substrate processing method, storage medium, and substrate processing apparatus

Abstract

To provide a simple solution for resolving problems caused by foam during liquid processing using processing liquids. [Solution] A substrate processing method according to one aspect of the present disclosure includes supplying the processing liquid to the surface of a substrate using a liquid supply unit having a nozzle capable of discharging the processing liquid, a source for supplying the processing liquid, and a supply pipe connecting the nozzle and the source; acquiring monitoring information at each of a plurality of monitoring locations in the liquid supply unit that allows estimation of whether or not bubbles are present in the processing liquid; and determining one or more countermeasures from a plurality of countermeasures for removing bubbles based on the monitoring information acquired at each of the plurality of monitoring locations.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing method, a storage medium, and a substrate processing apparatus.

Background Art

[0002] Patent Document 1 discloses a degassing device installed on a processing liquid supply line. The degassing device described in Patent Document 1 includes a dissolved gas extraction nozzle that extracts dissolved gas from a processing liquid containing dissolved gas in the form of bubbles, and a first tank that separates the extracted bubbles from the processing liquid while passing through the dissolved gas extraction nozzle.

Prior Art Documents

Patent Documents

[0003] [[ID=2"1]]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a substrate processing method, a storage medium, and a substrate processing apparatus that can easily execute measures for eliminating troubles caused by bubbles in liquid processing using a processing liquid.

Means for Solving the Problems

[0005] A substrate processing method according to one aspect of the present disclosure includes supplying the processing liquid to the surface of a substrate by a liquid supply unit having a nozzle capable of discharging the processing liquid, a supply source of the processing liquid, and a supply pipe connecting between the nozzle and the supply source; obtaining monitoring information capable of estimating whether bubbles are contained in the processing liquid at each of a plurality of monitoring locations in the liquid supply unit; and determining one or more countermeasures from a plurality of countermeasures for removing bubbles based on the monitoring information obtained at each of the plurality of monitoring locations.

Effects of the Invention

[0006] According to this disclosure, a substrate processing method, a storage medium, and a substrate processing apparatus are provided that can easily implement measures to resolve problems caused by foam in liquid processing using a processing liquid. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic plan view showing an example of a wafer processing system. [Figure 2] Figure 2 is a schematic front view showing an example of a wafer processing system. [Figure 3] Figure 3 is a schematic diagram showing an example of a liquid processing apparatus. [Figure 4] Figure 4 is a schematic diagram illustrating the arrangement of the liquid supply unit and the monitoring system. [Figure 5] Figure 5 is a schematic diagram showing an example of an inspection device. [Figure 6] Figure 6 is a block diagram showing an example of the functional configuration of a control device. [Figure 7] Figures 7(a) and 7(b) are schematic diagrams illustrating how the nozzle is imaged. [Figure 8] Figure 8 is a schematic diagram illustrating a wafer in a state where defects have formed. [Figure 9] Figure 9 is a block diagram showing an example of the hardware configuration of a control device. [Figure 10] Figure 10 is a flowchart showing an example of a processing flow executed by a control device. [Figure 11] Figure 11 is a table showing an example of countermeasure information. [Figure 12] Figure 12 is a flowchart showing an example of the processing flow performed by the control device. [Modes for carrying out the invention]

[0008] Hereinafter, the wafer processing system as a substrate processing apparatus according to this embodiment will be described with reference to the drawings. In this specification, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant explanations will be omitted.

[0009] <Wafer Processing System> First, the configuration of the wafer processing system according to this embodiment will be described. Figures 1 and 2 are schematic plan view and front view, respectively, showing the general configuration of the wafer processing system 1. In this embodiment, the case in which the wafer processing system 1 is a photolithography processing system that performs resist film formation processing and development processing on a wafer W (substrate) will be described as an example.

[0010] As shown in Figure 1, the wafer processing system 1 includes a cassette station 2 for loading and unloading cassettes C containing multiple wafers W, and a processing station 3 equipped with multiple processing devices for performing predetermined processing on the wafers W. The wafer processing system 1 has a configuration in which the cassette station 2, the processing station 3, and an interface station 4 for transferring wafers W between the processing station 3 and an adjacent exposure device (not shown) on the opposite side are integrally connected. Although two processing stations 3 are installed between the cassette station 2 and the interface station 4 as shown in Figure 1, there may be one or three or more processing stations.

[0011] The cassette station 2 is equipped with multiple cassette mounting tables 21 and wafer transport devices 22 and 23. The cassette station 2 transports wafers W between the cassette C placed on the mounting table 12 and the processing station 3 using the wafer transport device 22 or 23. For this purpose, the wafer transport devices 22 and 23 are equipped with drive mechanisms that have movement paths in each direction, such as horizontal (X and Y directions), vertical (Z direction), and around the vertical axis (θ direction), as needed, and may also be equipped with drive mechanisms that have movement paths in all directions. At least one of the wafer transfer devices 22 and 23 can transfer the cassette C and the wafer W, and can also transfer the wafer W with the processing station 3. The wafer transfer operation with the processing station 3 means, for example, transferring the wafer W between the third block G3 including a transfer device accessible by the wafer transfer device 33 in the processing station 3 described later. The third block G3 may include a plurality of transfer devices (not shown) arranged in the vertical direction.

[0012] In addition, an inspection device (not shown) for inspecting the wafer W may be provided at a position accessible by either of the wafer transfer devices 22 and 23.

[0013] The processing station 3 is provided with a plurality of blocks, for example, three blocks G1, G2, and G4 of the first, second, and fourth. Also, as shown in FIG. 2, a plurality of layers 31 including the first and second blocks G1 and G2 are stacked in the vertical direction. For example, the first block G1 is provided on the front side (the negative X direction side in FIG. 1) of the processing station 3, and the second block G2 is provided on the back side (the positive X direction side in FIG. 1) of the processing station 3. The fourth block G4 is provided on the interface station 5 side (the positive Y direction side in FIG. 1) of the processing station 3 or at the connection portion with another adjacent processing station 3. The fourth block G4 may include a plurality of transfer devices arranged in the vertical direction. Also, the aforementioned third block G3 may be provided in the processing station 3.

[0014] A plurality of processing devices, for example, a patterning film forming device and a development processing device not shown together, are arranged in the first block G1. As the patterning film forming device, for example, in addition to a resist film forming device, an antireflection film forming device can be included. For example, a plurality of processing devices are arranged side by side in the horizontal direction. The number, arrangement, and type of these processing devices can be arbitrarily selected.

[0015] In these patterning film forming apparatuses and development processing apparatuses, for example, a predetermined processing liquid is supplied onto the wafer W, or a predetermined gas is supplied. In this way, in the patterning film forming apparatus, formation of a resist film used as a mask when forming a pattern of a film on the lower layer side, and formation of an antireflection film or the like for efficiently performing light irradiation processing such as exposure processing are performed. On the other hand, in the development processing apparatus, a part of the exposed resist film is removed to form the concavo-convex shape as the mask. In one example, a liquid processing apparatus U1 is arranged as the patterning film forming apparatus.

[0016] For example, in the second block G2, heat treatment apparatuses (not shown) for performing heat treatment such as heating and cooling of the wafer W are provided side by side in the vertical direction and the horizontal direction. Also in the second block G2, although not shown in any figure, a hydrophilization treatment apparatus for performing hydrophilization treatment to enhance the adhesion between the resist liquid and the wafer W, and a peripheral exposure apparatus for exposing the outer peripheral portion of the wafer W are provided side by side in the vertical direction (Z direction in FIG. 2) and the horizontal direction. The number and arrangement of these heat treatment apparatuses, hydrophilization treatment apparatuses, and peripheral exposure apparatuses can also be arbitrarily selected.

[0017] As shown in FIG. 1, a wafer transfer region 32 is formed in the region sandwiched between the first block G1 and the second block G2 in a plan view. In the wafer transfer region 32, for example, a wafer transfer apparatus 33 is arranged.

[0018] The wafer transfer apparatus 33 has, for example, a transfer arm that is movable in the Y direction, the front-rear direction, the θ direction, and the vertical direction. The wafer transfer apparatus 33 moves within the wafer transfer region 32 and can transfer the wafer W to a predetermined apparatus within the surrounding first block G1, second block G2, third block G3, and fourth block G4. When there are a plurality of processing stations 3 as shown in FIG. 1, the wafer transfer apparatus 33 provided in the processing station 3 located on the interface station 4 side can transfer the wafer W to a predetermined apparatus within the fifth block G5 described later in addition to the first, second, and fourth blocks G1, G2, and G3.

[0019] Multiple wafer transfer devices 33 are arranged vertically, for example, as shown in Figure 2. One wafer transfer device 33 can transfer a wafer W to a predetermined device located at the height of multiple upper layers 31 of the stacked layers 31. Another wafer transfer device 33 can transfer the wafer W to a predetermined device located at the height of multiple layers 31 below those layers 31. Multiple wafer transfer areas 32 are provided to enable this type of wafer transfer W. The number of wafer transfer devices 33 and the number of layers 31 corresponding to one wafer transfer device 33 can be arbitrarily selected, such as providing one wafer transfer device 33 for each layer 31.

[0020] Furthermore, a shuttle transport device (not shown) may be provided in the wafer transport area 32 or in the first block G1 or the second block G2. The shuttle transport device transports the wafer W linearly between a space adjacent to one side of the processing station 3 and another space adjacent to the opposite side.

[0021] Interface station 4 includes a fifth block G5 equipped with multiple transfer devices, and wafer transport devices 41 and 42. Interface station 4 transports wafers W between the fifth block G5, where wafers W are transferred by wafer transport device 33, and the exposure apparatus using wafer transport device 41 or 42. For this purpose, wafer transport devices 41 and 42 are each equipped with a drive mechanism having movement paths in various directions such as horizontal (X direction, Y direction), vertical (Z direction), and around the vertical axis (θ direction), as needed, and may also be equipped with a drive mechanism having movement paths in all directions. At least one of wafer transport devices 41 and 42 can support the wafer W and transport the wafer W between the transfer devices and the exposure apparatus in the fifth block G5.

[0022] A cleaning device for cleaning the surface of the wafer W, and the aforementioned peripheral exposure device, may be provided within the interface station 4 in a location accessible by either the wafer transport device 41 or 42.

[0023] The inspection device may be located in the cassette station 2 as described above, but it may also be located in the processing station 3 and the interface station 4, in a position accessible by any of the transport arms (33, 41, 42 in Figure 1 or Figure 2) located inside each of them. In one example, the inspection device U3 is located in the second block G2.

[0024] The wafer processing system 1 described above is provided with a control device 100. The control device 100 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program that controls the processing of wafers W in the wafer processing system 1. The program storage unit also stores a program that controls the operation of the various processing devices and transport devices and other drive systems to realize wafer processing in the wafer processing system 1. The above program may have been recorded on a storage medium H readable by the computer and installed from the storage medium H to the control device 100. The storage medium H may include ROM, RAM, or a hard disk, but its structure and type are not limited, and it may be temporary or non-temporary. The control device 100 may include a part that stores, reads, and executes the program for realizing wafer processing and performs related communications, and the location of each part may be either inside or outside the wafer processing system 1. The control device 100 may be one or more circuits, and may be provided as a single unit or in parts.

[0025] <Operation of the wafer processing system> The wafer processing system 1 is configured as described above. Next, an example of wafer processing performed using the wafer processing system 1 configured as described above will be explained.

[0026] First, a cassette C containing multiple wafers W is brought into the cassette station 2 of the wafer processing system 1 and placed on the cassette tray 21. Next, each wafer W in the cassette C is sequentially removed by the wafer transport device 22 or 23 and transported to the transfer device of the third block G3.

[0027] The wafer W, transported to the transfer device in the third block G3, is supported by the wafer transfer device 33 and transported to a hydrophobic treatment device located in the second block G2, where a hydrophobic treatment is performed. Next, the wafer transfer device 33 transports the wafer to a resist film forming device (e.g., a liquid treatment device U1) where a resist film is formed on the wafer W. After that, it is transported to a heat treatment device for pre-baking before being transported to the transfer device in the fifth block G5. Note that if there are multiple processing stations 3 as shown in Figures 1 and 2, the wafer W is first placed in the transfer device in the fourth block G4 before being transported to the transfer device in the fifth block G5, and then transferred between the multiple wafer transfer devices 33. In addition, if necessary, the wafer W may be transported by the wafer transfer device 33 to a peripheral exposure device where the peripheral edge of the wafer is exposed.

[0028] The wafer W, transported to the transfer device of the fifth block G5, is then transported to the exposure device by wafer transport devices 41 and 42 and exposed in a predetermined pattern. The wafer W may be cleaned in a cleaning device before the exposure process.

[0029] The exposed wafer W is transported by wafer transport devices 41 and 42 to the transfer device for the fifth block G5. It is then transported by wafer transport device 33 to a heat treatment device for post-exposure baking.

[0030] The wafer W, which has been baked after exposure, is transported by the wafer transport device 33 to the developing device and developed. After development is complete, the wafer W is transported by the wafer transport device 33 to the heat treatment device 40 and subjected to post-bake treatment.

[0031] Subsequently, the wafer W is transported by the wafer transport device 33 to the transfer device of the third block G3, and then transported by the wafer transport device 22 or 23 of the cassette station 2 to cassette C on a predetermined cassette mounting table 21. In this way, the series of photolithography processes is completed.

[0032] It should be noted that the wafer processing system in this disclosure is not limited to the configuration and operation described above. For example, in the above embodiment, the wafer processing system was directly connected to the exposure apparatus and the wafer W was transferred between the interface station 4 and the exposure apparatus, but the wafer processing system does not have to be directly connected to the exposure apparatus. In that case, for example, the wafer W is transported from the cassette station 2 to the processing station 3, the necessary processing is performed, and then it is transported back to the cassette station 2 for removal outside the system. Also, among the processing devices listed, those that are not necessary may not be provided in the wafer processing system, or processing may not be performed in those devices.

[0033] (Liquid treatment equipment) Next, an example of the liquid processing apparatus U1 will be described in detail with reference to Figures 3 and 4. As shown in Figure 3, the liquid processing apparatus U1 comprises a rotating holding unit 50 and a processing liquid supply unit 60 (liquid supply unit).

[0034] The rotating holding unit 50 holds and rotates the wafer W based on the operation instructions of the control device 100. The rotating holding unit 50 has a holding unit 54 and a drive unit 56. The holding unit 54 holds the wafer W with its surface Wa facing upward. The holding unit 54 supports the center of the horizontally positioned wafer W and holds the wafer W by suction (e.g., vacuum suction). The drive unit 56 is a rotary actuator including a power source such as an electric motor, and rotates the holding unit 54 around a vertical rotation axis. As a result, the wafer W rotates around the vertical rotation axis.

[0035] The processing liquid supply unit 60 supplies processing liquid to the surface Wa of the wafer W. The processing liquid supply unit 60 includes, for example, a nozzle 70, a liquid delivery pipe 72, a discharge valve 74, a liquid delivery unit 80, a liquid delivery pipe 78, and a replenishment unit 90, as shown in Figure 4. In the following description, the processing liquid supplied to the wafer W by the processing liquid supply unit 60 will be referred to as "processing liquid L". The terms "upstream" and "downstream" will be used based on the flow of processing liquid L. That is, the processing liquid L flows (moves) from upstream to downstream. The replenishment unit 90, liquid delivery pipe 78, liquid delivery unit 80, discharge valve 74, and nozzle 70 are arranged in this order from upstream.

[0036] The nozzle 70 is a component capable of dispensing a processing liquid L. The nozzle 70, for example, is positioned above the wafer W and dispenses the processing liquid L toward the surface Wa of the wafer W (see also Figure 3). By dispensing the processing liquid L from the nozzle 70 toward the surface Wa of the rotating wafer W, the processing liquid L is applied (supplied) to the surface Wa of the wafer W.

[0037] The liquid delivery pipe 72 connects the nozzle 70 and the liquid delivery unit 80, forming a flow path that guides the processed liquid L from the liquid delivery unit 80 to the nozzle 70. One downstream end of the liquid delivery pipe 72 is connected to the nozzle 70, and the other upstream end of the liquid delivery pipe 72 is connected to the liquid delivery unit 80.

[0038] The discharge valve 74 is located in the flow path formed by the liquid delivery pipe 72. Based on an operation instruction from the control device 100, the discharge valve 74 opens and closes the flow path in the liquid delivery pipe 72 (the flow path between the liquid delivery unit 80 and the nozzle 70). When the discharge valve 74 is open, the processing liquid L is discharged from the nozzle 70 toward the surface Wa of the wafer W, and when the discharge valve 74 is closed, the discharge of the processing liquid L from the nozzle 70 stops. The discharge valve 74 is, for example, an air-operated valve.

[0039] The liquid delivery unit 80 delivers the processing liquid L to the nozzle 70 via the liquid delivery pipe 72. The liquid delivery unit 80 may also deliver the processing liquid L towards the nozzle 70 at a predetermined pressure. The liquid delivery unit 80 includes, for example, a pump 82, a connecting pipe 84, and a filter 86.

[0040] Pump 82 receives the processing liquid L supplied from the replenishment unit 90, pressurizes the received processing liquid L, and sends it toward the nozzle 70. Pump 82 includes a receiving chamber for containing the processing liquid L and a contraction section for expanding and contracting the receiving chamber. Pump 82 expands the receiving chamber with the contraction section to receive the processing liquid L, and contracts the receiving chamber with the contraction section to send the processing liquid L downstream. A tube diaphragm pump, a diaphragm pump, or a bellows pump may be used as pump 82.

[0041] The connecting pipe 84 connects the pump 82 and the filter 86. One downstream end of the connecting pipe 84 is connected to the pump 82, and the other upstream end is connected to the filter 86. The connecting pipe 84 forms part of the flow path that guides the processing liquid L replenished from the replenishment unit 90 to the pump 82. The filter 86 captures at least some of the foreign matter contained in the processing liquid L flowing through the flow path between the replenishment unit 90 and the pump 82.

[0042] The liquid delivery pipe 78 connects the filter 86 and the replenishment unit 90. One downstream end of the liquid delivery pipe 78 is connected to the liquid delivery unit 80 (filter 86), and the other upstream end of the liquid delivery pipe 78 is connected to the replenishment unit 90. The liquid delivery pipe 78 and the connecting pipe 84 form a flow path for the processed liquid L from the replenishment unit 90 to the pump 82. The liquid delivery pipe 78 may be divided into a first section, a second section, and a third section, in order from the upstream side. The first section is a section that forms a flow path for the processed liquid L to flow from top to bottom. The second section is a section that forms a flow path for the processed liquid L to flow in a substantially horizontal direction. The third section is a section that forms a flow path for the processed liquid L to flow from bottom to top.

[0043] The replenishment unit 90 replenishes the processing liquid L from the processing liquid L supply source to the liquid delivery unit 80. As described above, a flow path for the processing liquid L is formed between the replenishment unit 90 and the pump 82 by the liquid delivery pipe 78 and the connecting pipe 84, and a filter 86 is provided on this flow path. The replenishment unit 90 replenishes the liquid delivery unit 80 with processing liquid L to be delivered toward the nozzle 70. The replenishment unit 90 includes, for example, a supply source 92, a liquid delivery pipe 94, and a replenishment tank 96.

[0044] The supply source 92 is the source of the processing liquid L. The supply source 92 is, for example, a bottle containing the processing liquid L. The bottle serving as the supply source 92 may be replaceable. The liquid delivery pipe 94 connects the supply source 92 to the replenishment tank 96. One downstream end of the liquid delivery pipe 94 is connected to the replenishment tank 96, and the other upstream end of the liquid delivery pipe 94 is connected to the supply source 92. The supply source 92 delivers the processing liquid L to the replenishment tank 96 via the liquid delivery pipe 94, for example, by supplying pressurizing gas.

[0045] The replenishment tank 96 stores the processing liquid L. The replenishment tank 96 receives the processing liquid L from the supply source 92, pressurizes the received processing liquid L, and sends it to the liquid delivery section 80 through the liquid delivery pipe 78 (sending it to the pump 82 through the liquid delivery pipe 78 and connecting pipe 84). The replenishment tank 96 may have the same pump function as the pump 82, or a pump may be connected to the downstream side of the replenishment tank 96. Alternatively, the processing liquid L may be pressurized by supplying gas into the replenishment tank 96 and sent downstream from the replenishment tank 96.

[0046] In the processing liquid supply unit 60, the nozzle 70 and the supply source 92 are connected by piping (hereinafter referred to as "supply piping 69"; see also Figure 3). One downstream end of the supply piping 69 is connected to the nozzle 70, and the other upstream end of the supply piping 69 is connected to the supply source 92. The supply piping 69 forms a flow path that guides the processing liquid L from the supply source 92 to the nozzle 70. In the example shown in Figure 4, the supply piping 69 is composed of a liquid delivery pipe 72, a connecting pipe 84, a liquid delivery pipe 78, and a liquid delivery pipe 94.

[0047] (Inspection device) Next, an example of the inspection apparatus U3 will be described in detail with reference to Figure 5. The inspection apparatus U3 has the function of capturing image data of the surface Wa of the wafer W. The inspection apparatus U3 may also capture image data of the entire surface Wa of the wafer W by capturing image of the entire surface Wa. As shown in Figure 5, the inspection apparatus U3 includes, for example, a housing 150, a holding unit 151, a linear drive unit 152, an imaging unit 153, and an optical path adjustment unit 154.

[0048] The holding unit 151 holds the wafer W horizontally with its surface Wa facing upward. The linear drive unit 152 includes a power source, such as an electric motor, and moves the holding unit 151 along a horizontal, straight path. The imaging unit 153 includes a camera 155, such as a CCD camera. The camera 155 is located near one end of the housing 150 in the direction of movement of the holding unit 151 and is directed toward the other end in that direction of movement.

[0049] The optical path adjustment unit 154 emits light into the imaging range and guides the reflected light from that imaging range to the camera 155. For example, the optical path adjustment unit 154 includes a half mirror 156 and a light source 157. The half mirror 156 is located higher than the holding unit 151 and is positioned in the middle of the movement range of the linear drive unit 152, reflecting light from below to the camera 155. The light source 157 is located above the half mirror 156 and emits illumination light downward through the half mirror 156.

[0050] The inspection device U3 operates as follows to acquire image data of the wafer surface Wa of the wafer W. First, the linear drive unit 152 moves the holding unit 151. This causes the wafer W to pass under the half mirror 156. During this passage process, reflected light from each part of the wafer surface Wa of the wafer W is sequentially sent to the camera 155. The camera 155 forms an image of the reflected light from each part of the wafer surface Wa of the wafer W, and generates image data of the wafer surface Wa (the entire surface Wa) of the wafer W. The image obtained by imaging the wafer surface Wa of the wafer W changes depending on the state of the wafer surface Wa of the wafer W. In the inspection device U3, image data of the wafer surface Wa of the wafer W is acquired as information indicating the state of the wafer surface Wa of the wafer W.

[0051] Image data generated by camera 155 is sent to control device 100. The control device 100 can inspect the condition of the surface Wa of wafer W based on the image data of the surface Wa. For example, it can inspect for defects on the surface Wa of wafer W. One type of defect on the surface Wa is caused by the presence of bubbles in the processing liquid L before it is discharged onto the surface Wa (a mixture of processing liquid L and bubbles).

[0052] (Monitoring system) Next, an example of the monitoring system 200 provided by the wafer processing system 1 will be described with reference to Figures 4 and 6-8. The monitoring system 200 (monitoring unit) is a system that acquires information that allows for the estimation of whether or not bubbles are present in the processing liquid L at each of the multiple monitoring points in the processing liquid supply unit 60. Hereinafter, the information that allows for the estimation of whether or not bubbles are present in the processing liquid L (that the processing liquid L and bubbles are mixed together due to the generation or incorporation of bubbles) will be referred to as "monitoring information". The multiple monitoring points are locations in the processing liquid supply unit 60 that are different from each other. The monitoring system 200 acquires the above monitoring information for each monitoring point.

[0053] The monitoring points in the processing liquid supply unit 60 may be predetermined. For example, multiple monitoring points may be set in the supply source 92, the nozzle 70, and the flow path in the supply piping 69. In this disclosure, the monitoring information that can estimate whether or not the processing liquid L contains foam may also include information that detects foam itself. Foam contained in the processing liquid L may also include foam present on the liquid surface.

[0054] The monitoring system 200 may acquire monitoring information at multiple monitoring locations by combining different means. The monitoring system 200 may include, for example, one or more dissolved concentration sensors 210, one or more bubble sensors 220, and a nozzle camera 230.

[0055] The monitoring system 200 may have one or more dissolved concentration sensors 210, or one dissolved concentration sensor 210. The dissolved concentration sensor 210 is a sensor that measures the concentration of a specific substance (a predetermined component in the processing liquid L) contained in the processing liquid L. For example, the dissolved concentration sensor 210 measures the concentration of oxygen in the processing liquid L. The dissolved concentration sensor 210 may be an electrochemical sensor or an optical sensor. If the dissolved concentration of a specific substance (e.g., oxygen) in the processing liquid L exceeds a predetermined value, it can be inferred that foam is contained in the processing liquid L. The dissolved concentration sensor 210 may output information indicating the measured value of the dissolved concentration to the control device 100 as monitoring information.

[0056] The dissolved concentration sensor 210 may be located in a section of the supply flow path within the supply piping 69 upstream of the filter 86. The dissolved concentration sensor 210 may be located, for example, on the flow path within the liquid delivery pipe 94. Alternatively, the dissolved concentration sensor 210 may be located on the flow path within the liquid delivery pipe 78 instead of the flow path within the liquid delivery pipe 94. In one example, the dissolved concentration sensor 210 may be located in a second section of the flow path within the liquid delivery pipe 78 through which the processed liquid L flows in a substantially horizontal direction.

[0057] The monitoring system 200 may have two dissolved concentration sensors 210 instead of one. In this case, one dissolved concentration sensor 210 may be placed in the flow path within the liquid delivery pipe 94, and the other dissolved concentration sensor 210 may be placed in the flow path within the liquid delivery pipe 78. Note that the arrangement and number of dissolved concentration sensors 210 are examples, and the dissolved concentration sensors 210 may be placed in a section of the supply flow path within the supply piping 69 downstream of the filter 86. The location where the dissolved concentration sensors 210 are placed corresponds to the monitoring location.

[0058] The monitoring system 200 may have one or more bubble sensors 220, or a plurality of bubble sensors 220. A bubble sensor 220 is a sensor that detects the presence of bubbles (gas bubbles) themselves. A bubble sensor 220 may be an ultrasonic sensor that detects bubbles using the reflection or transmission of ultrasonic waves. A bubble sensor 220 may be an optical sensor that detects bubbles using the reflection or transmission of light. A bubble sensor 220 may be a capacitive sensor that detects bubbles using the change in capacitance caused by the presence of bubbles in a liquid. When a bubble sensor 220 detects a bubble, it may output information to the control device 100 indicating that a bubble has been detected as monitoring information.

[0059] A bubble sensor 220 may be placed in the flow path between the supply source 92 and the replenishment tank 96. If a dissolved concentration sensor 210 is placed in the flow path between the supply source 92 and the replenishment tank 96, the bubble sensor 220 does not need to be placed in this flow path. A bubble sensor 220 may be placed in the flow path between the replenishment tank 96 and the filter 86. A bubble sensor 220 may be placed in the third section of the flow path between the replenishment tank 96 and the filter 86, where the processing liquid L flows from bottom to top. If a bubble sensor 220 is placed in the flow path between the replenishment tank 96 and the filter 86, the bubble sensor 220 does not need to be placed in this flow path.

[0060] A bubble sensor 220 may be placed in the flow path between the filter 86 and the pump 82. A bubble sensor 220 may be placed in the flow path between the pump 82 and the discharge valve 74. A bubble sensor 220 may be placed in the flow path between the discharge valve 74 and the nozzle 70. The location where the bubble sensor 220 is installed corresponds to the monitoring location.

[0061] For the sake of explanation, the supply flow path within the supply pipe 69 will be divided into the following five sections, and the names of each section will be defined as follows. Section I: Flow path between supply source 92 and replenishment tank 96 Section II: Flow path between replenishment tank 96 and filter 86 Section III: Flow path between filter 86 and pump 82 Section IV: Flow path between pump 82 and discharge valve 74 Section V: Flow path between discharge valve 74 and nozzle 70

[0062] In one example, a dissolved concentration sensor 210 is placed in section I, and bubble sensors 220 are placed in sections II, III, IV, and V. Alternatively, a dissolved concentration sensor 210 may be placed in section I, and bubble sensors 220 may be placed in sections I, II, III, IV, and V. In another example, a dissolved concentration sensor 210 is placed in section II, and bubble sensors 220 are placed in sections I, III, IV, and V. Alternatively, a dissolved concentration sensor 210 may be placed in section II, and bubble sensors 220 may be placed in sections I, II, III, IV, and V.

[0063] The nozzle camera 230 is positioned near the nozzle 70 and is capable of imaging the inside or tip of the nozzle 70. The nozzle camera 230 is, for example, a digital camera. The nozzle camera 230 may generate video data or still image data. The nozzle camera 230 is provided to acquire image data that can estimate whether or not bubbles are present in the processing liquid L upstream of the tip of the nozzle 70 (for example, in the section above the nozzle 70).

[0064] In one example, the nozzle camera 230 is positioned to capture an image of the area within the field of view, including the tip of the nozzle 70, from the side of the nozzle 70, as shown in Figure 7(a). In Figure 7(a), an example is shown where the processing liquid supply unit 60 has a plurality of nozzles 70. In this case, the processing liquid L may be supplied to one of the plurality of nozzles 70. The processing liquid supply unit 60 may have a nozzle holder 70a. The nozzle holder 70a is a member that supports the plurality of nozzles 70, and a drive unit for moving the plurality of nozzles 70 may be connected to the nozzle holder 70a. The nozzle camera 230 may be attached to the nozzle holder 70a, or it may move together with the nozzle 70 so that its relative position to the nozzle 70 does not change.

[0065] If bubbles are mixed into or generated in the processing liquid L in the section upstream of the nozzle 70 where the discharge port is located, the presence of bubbles will cause the liquid level of the processing liquid L inside the nozzle 70 to drop, as shown in Figure 7(b). For example, if the liquid level of the processing liquid L drops further after it has dropped enough to form a puddle at the tip of the nozzle 70, the puddle at the tip will fall off (a drip of processing liquid L occurs). When the puddle of processing liquid L falls onto the surface Wa of the wafer W, a defect occurs, i.e., a defect caused by bubbles. Figure 8 schematically shows a state in which a defect has occurred due to the unintentional dripping of processing liquid L from the tip of the nozzle 70. In Figure 8, the part indicated by "d" shows the defect (defective area).

[0066] By monitoring the liquid level in the image data (nozzle image data) obtained by the nozzle camera 230, it is possible to estimate whether or not bubbles are present in the processing liquid L upstream of the tip of the nozzle 70. The nozzle camera 230 may also output the generated image data as monitoring information to the control device 100. Furthermore, it is also possible to detect defects d from the image data (surface image data) obtained by the inspection device U3. By understanding the characteristics of defects d caused by dripping, it is possible to infer from the surface image data that bubbles are present in the processing liquid L.

[0067] (Control device) Returning to Figure 6, the control device 100 has the following functional components (referred to as "functional blocks" in this disclosure): a monitoring information acquisition unit 112, a foam presence determination unit 114, an operation determination unit 116, a countermeasure information holding unit 118, a countermeasure execution unit 120, a result storage unit 122, and an operation adjustment unit 124. The processes executed by these functional blocks correspond to the processes executed by the control device 100.

[0068] The monitoring information acquisition unit 112 acquires monitoring information from each of the multiple monitoring points set in the processing liquid supply unit 60. In one example, the monitoring information acquisition unit 112 acquires information indicating the measured value of dissolved concentration from the dissolved concentration sensor 210 and information indicating that bubbles have been detected from the bubble sensor 220. The monitoring information acquisition unit 112 may also acquire image data from the nozzle camera 230. In addition to acquiring monitoring information from the monitoring system 200, the monitoring information acquisition unit 112 may also acquire image data from the inspection device U3.

[0069] The foam presence determination unit 114 determines whether or not foam is present in the processing liquid L, that is, whether or not it is in a foam-containing state, based on the monitoring information acquired by the monitoring information acquisition unit 112. The foam presence determination unit 114 may also detect defects caused by the presence of foam in the processing liquid L (foam-containing state) based on image data acquired from the inspection device U3.

[0070] The operation determination unit 116 determines one or more corrective actions from among multiple corrective actions for removing foam, based on monitoring information acquired at each of the multiple monitoring locations. Multiple corrective actions for removing foam (candidate corrective actions) are predetermined. The operation determination unit 116 may also select one or more corrective actions depending on the combination of monitoring information acquired at multiple monitoring locations at a certain monitoring timing.

[0071] The response information holding unit 118 holds response information. The response information is information that associates a combination of the results of monitoring information from multiple monitoring locations with one or more response actions. In other words, by referring to the response information, once a combination of the results of monitoring information from multiple monitoring locations is determined, one or more response actions are determined according to that combination.

[0072] In the response information, at least some of the combinations of the results of acquiring monitoring information at multiple monitoring locations are associated with two or more candidate actions for removing foam, and a priority order for these two or more candidate actions may be defined. When two or more response actions are determined (selected), the action determination unit 116 may further determine the execution order of these two or more response actions according to the response information.

[0073] The response execution unit 120 controls the processing liquid supply unit 60 to execute one or more response actions determined by the operation determination unit 116. The response execution unit 120 may also control the processing liquid supply unit 60 so that the response actions determined by the operation determination unit 116 are executed without taking into account instructions from an operator such as a worker. In this way, the control device 100 may autonomously perform a process that includes determining a response action according to the monitoring information obtained from the monitoring system 200, and causing the device to execute the determined response action.

[0074] The result storage unit 122 stores the results of executing one or more corrective actions determined by the action determination unit 116 as execution result information. The execution result information may include at least one of the following: information indicating whether the foam was removed when one or more corrective actions were performed, the number of corrective actions performed to remove the foam, and information indicating how long it took to remove the foam.

[0075] The operation adjustment unit 124 may change the priority order defined in the handling information based on the execution result information stored by the result storage unit 122. Depending on the stored execution result information, the operation adjustment unit 124 may decide not to change the priority order in the handling information.

[0076] Figure 9 schematically shows the hardware configuration of the control device 100. As shown in Figure 9, the control device 100 has a circuit 140. The circuit 140 has a processor 141, a memory 142, a storage 143, a timer 144, and an input / output port 145. The storage 143 is composed of one or more non-volatile memory devices such as flash memory or a hard disk. The storage 143 stores a program for causing the computer to execute the board processing method described later. The memory 142 is composed of one or more volatile memory devices such as random access memory. The memory 142 temporarily stores the program loaded from the storage 143.

[0077] The processor 141 is composed of one or more computing devices such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The processor 141 constitutes the above-mentioned functional block by executing a program loaded into memory 142. The calculation results by the processor 141 are temporarily stored in memory 142. The timer 144 measures the elapsed time by counting clock pulses. The input / output port 145 performs input and output of electrical signals with the dissolved concentration sensor 210, bubble sensor 220, nozzle camera 230, inspection device U3, and processing liquid supply unit 60, etc., in response to requests from the processor 141.

[0078] The control device 100 is not necessarily limited to having each function configured by a program. For example, the control device 100 may have at least some functions configured by a dedicated logic circuit or an ASIC (Application Specific Integrated Circuit) that integrates such a circuit. The program may be provided by being permanently recorded on a tangible recording medium such as a CD-ROM, DVD-ROM, or semiconductor memory. Alternatively, the program may be provided via a communication network as a data signal superimposed on a carrier wave.

[0079] [Substrate Processing Method] Next, an example of a substrate processing method performed in the wafer processing system 1 will be described. This substrate processing method includes a supply step, a monitoring information acquisition step, and an operation determination step. The supply step is a step of supplying processing liquid L to the surface Wa of the wafer W by the processing liquid supply unit 60. The monitoring information acquisition step is a step of acquiring monitoring information at each of the multiple monitoring points in the processing liquid supply unit 60. The monitoring information acquisition step is performed, for example, by the monitoring system 200 and the monitoring information acquisition unit 112 of the control device 100. The operation determination step is a step of determining one or more countermeasures from among multiple countermeasures for removing bubbles based on the monitoring information acquired at each of the multiple monitoring points. The operation determination step is performed, for example, by the operation determination unit 116.

[0080] In the monitoring process, image data may be acquired by a nozzle camera 230 that images the inside or tip of the nozzle 70, as information that can estimate whether or not bubbles are present in the processing liquid L upstream of the tip of the nozzle 70. In the monitoring process, monitoring information may be acquired using a plurality of sensors arranged at different positions on the supply flow path formed by the supply piping 69 of the processing liquid supply unit 60. The plurality of sensors used in the monitoring process may include at least one of the dissolved concentration sensor 210 and the bubble sensor 220 (for example, both the dissolved concentration sensor 210 and the bubble sensor 220).

[0081] In the operation determination step, one or more countermeasures may be selected from among multiple countermeasures according to countermeasure information that associates combinations of acquired monitoring information results from multiple monitoring points with combinations of actions for removing bubbles. If two or more countermeasures are selected in the operation determination step, the execution order of these two or more countermeasures may be further determined according to the countermeasure information. The substrate processing method may further include a control step. The control step is a step of controlling the processing liquid supply unit 60 to execute the one or more countermeasures determined in the operation determination step. The control step is executed, for example, by the countermeasure execution unit 120.

[0082] The substrate processing method may further include an accumulation step and an operation adjustment step. The accumulation step is a step of accumulating the results of executing one or more countermeasure operations determined in the operation determination step as execution result information. The accumulation step is performed, for example, by a result accumulation unit 122. The operation adjustment step is a step of changing the priority order defined in the countermeasure information based on the execution result information accumulated in the accumulation step. The operation adjustment step is performed, for example, by an operation adjustment unit 124.

[0083] The substrate processing method may further include a surface imaging step and a defect detection step. The surface imaging step is a step of imaging the surface Wa of the wafer W after the processing liquid L has been supplied by the processing liquid supply unit 60. The surface imaging step is performed, for example, by an inspection device U3. The defect detection step is a step of detecting defects d caused by the presence of bubbles in the processing liquid L, based on the image data obtained in the surface imaging step. The defect detection step is performed, for example, by a bubble presence determination unit 114.

[0084] (Processing flow) Next, an example of the processing flow executed by the control device 100 will be described with reference to Figures 10, 11, and 12. Hereinafter, it will be assumed that the monitoring system 200 consists of either a dissolved concentration sensor 210 or a bubble sensor 220, located in each of the aforementioned sections I, II, III, IV, and V, and that a nozzle camera 230 is located near the nozzle 70.

[0085] In this processing flow, the control device 100 first executes step S01. In step S01, for example, the monitoring information acquisition unit 112 starts acquiring monitoring information from the monitoring system 200 for each of the pre-set monitoring points in the processing liquid supply unit 60. Thereafter, the monitoring information acquisition unit 112 repeatedly acquires monitoring information for each monitoring point at predetermined acquisition timings. Note that acquiring monitoring information also includes waiting to receive output from the bubble sensor 220.

[0086] Next, the control device 100 executes step S02. In step S02, for example, the foam presence determination unit 114 waits until a predetermined determination timing is reached. The determination timing is set in advance by an operator, such as a worker. In one example, the determination timing is set so that a determination of whether or not foam is present is performed during the period when the supply of the processing liquid L to the surface Wa of the wafer W is being waited for. The determination timing may be set so that the number of times the determination is performed differs depending on the length of the waiting period.

[0087] Next, the control device 100 executes step S03. In step S03, for example, the foam presence determination unit 114 determines whether or not foam is present in the processing liquid L before discharge from the processing liquid supply unit 60, based on the monitoring information for each monitoring location obtained immediately before the determination timing. The foam presence determination unit 114 may determine that foam is present in the processing liquid L at a monitoring location where a dissolved concentration sensor 210 is located if the measurement value from the dissolved concentration sensor 210 is greater than a predetermined threshold. The foam presence determination unit 114 may also determine that foam is not present in the processing liquid L at a monitoring location if the measurement value from the dissolved concentration sensor 210 is less than or equal to a predetermined threshold.

[0088] The foam presence determination unit 114 may determine that foam is present in the processing liquid L at a monitoring location if the foam sensor 220 outputs a signal indicating the detection of foam at that monitoring location. The foam presence determination unit 114 may also determine that foam is not present in the processing liquid L at that monitoring location if it does not receive a signal indicating the detection of foam from the foam sensor 220.

[0089] The foam presence determination unit 114 may detect the liquid level (liquid height) of the processing liquid L inside the nozzle 70 from image data obtained from the nozzle camera 230. The foam presence determination unit 114 may then determine that foam is present in the processing liquid L in the upstream section of the nozzle 70 if the liquid level of the processing liquid L inside the nozzle 70 is below a predetermined level. The foam presence determination unit 114 may then determine that no foam is detected in the processing liquid L inside the nozzle 70 if the liquid level of the processing liquid L inside the nozzle 70 is not below a predetermined level. In one example, the predetermined level is set to a height position a few millimeters below the tip of the nozzle 70.

[0090] Next, the control device 100 executes step S04. In step S04, for example, the foam presence determination unit 114 determines, based on the determination result in step S03, whether or not foam is present in the processing liquid L throughout the processing liquid supply unit 60. If the foam presence determination unit 114 determines that foam is present in the processing liquid L at at least some of the multiple monitoring locations, it determines that foam is present in the processing liquid L at the processing liquid supply unit 60 at that determination timing. If the foam presence determination unit 114 determines that foam is not present in the processing liquid L at all of the multiple monitoring locations of the processing liquid supply unit 60, it determines that foam is not present in the processing liquid L at the processing liquid supply unit 60 at that determination timing.

[0091] If, in step S04, it is determined that the processing liquid L in the processing liquid supply unit 60 does not contain foam (step S04: No), the control device 100 returns to step S02. Thereafter, the control device 100 repeats the processes from steps S02 to S04.

[0092] On the other hand, if it is determined in step S04 that the processing liquid L in the processing liquid supply unit 60 contains foam (step S04: YES), the control device 100 proceeds to step S05. In step S05, for example, the operation determination unit 116 determines one or more corrective actions from among a plurality of candidate actions for removing foam, based on the determination results for each monitoring location in step S03. The operation determination unit 116 may also determine one or more corrective actions by referring to the corrective action information held by the corrective action information holding unit 118.

[0093] Here, we will explain a specific example of the response information. For each of the above-mentioned sections I, II, III, IV, and V, we will assume that the response actions to be taken when foam is detected in each section are defined as follows. Section I: Operation A, Operation B Section II: Operation C Section III: Operation D, Operation E Section IV: Operation F Section V: Operation G, Operation H

[0094] Operations A to H represent different countermeasures and are predetermined as candidate countermeasures for removing foam depending on the section. If two or more operations are set for a single section, at least some of the two or more operations will be executed in one of the specified order. If the presence of foam is detected from the image data from the nozzle camera 230, one or more countermeasures from operations A to H may be executed. Operations A to H include, for example, operations to agitate the components placed in the supply pipe 69 using ultrasound or temperature, and operations to adjust the pressure in the container containing the processing liquid L (for example, operations to adjust by lowering the pressure set value). Operations A to H may also include operations that utilize means for removing foam provided on the components placed in the supply pipe 69.

[0095] Figure 11 is a table showing an example of response information. In the response information, the response action is determined according to the combination of the results of the acquisition of monitoring information from multiple monitoring points (more specifically, the combination of the results of the determination of whether or not foam is present in the processing liquid L based on the monitoring information). Since the presence or absence of foam in the processing liquid L is monitored at multiple monitoring points, and foam may be detected at multiple points rather than just one, there are various combinations (patterns) of the results of the acquisition of monitoring information. In the response information, one or more response actions are associated with each combination of the results of the acquisition of monitoring information. Note that the combination of the results of the acquisition of monitoring information in the response information can also be said to be the combination of the monitoring results from multiple monitoring points.

[0096] In Figure 11, the "Monitoring Information" column shows a checkmark next to the monitoring location where foam was detected. For example, in combination number "No. 1," foam was detected in section I, but not in any other monitoring location. In combination "No. 7," foam was detected in sections I and II, but not in any other monitoring location.

[0097] In some combinations of acquired monitoring information, two or more corrective actions are associated with them, and a priority order is defined for these two or more corrective actions. Priority refers to the order in which the corrective actions are executed. For example, in combination "No. 1," actions A and B are associated, and the priority order is set so that action A is executed first and action B is executed second. At least at the initial stage when wafer processing system 1 is installed (including the case when the monitoring system 200 and control device 100 described above are first applied to an existing wafer processing system), the priority order in the corrective information is predetermined.

[0098] Returning to Figure 10, after step S05 is executed, the control device 100 executes step S06. In step S06, for example, the action execution unit 120 controls the processing liquid supply unit 60 to execute one or more action actions determined in step S05. If two or more action actions were selected in step S05, the action execution unit 120 causes the processing liquid supply unit 60 to execute the two or more selected action actions in order according to the determined execution order.

[0099] The response execution unit 120 may, after instructing the processing liquid supply unit 60 to execute one or more of the determined response actions, continue to have the processing liquid supply unit 60 perform one or more response actions until it is determined that no bubbles are present in the processing liquid L at all of the multiple monitoring locations. When two or more response actions are to be performed, the response execution unit 120 may terminate the execution of the response actions midway if it is determined that no bubbles are present in the processing liquid L at all of the multiple monitoring locations after performing some of the response actions.

[0100] The response execution unit 120 may repeatedly instruct the processing liquid supply unit 60 to perform one or more response actions until it is determined that no foam is present in the processing liquid L at all of the multiple monitoring locations. If the state in which foam is determined to be present in the processing liquid L persists even after one or more response actions have been repeatedly performed, the response execution unit 120 may notify an operator such as a worker of an alarm or similar.

[0101] Next, the control device 100 executes step S07. In step S07, for example, the result storage unit 122 records the execution result of the corrective action in step S06. The result storage unit 122 may record the information by associating the result of the decision on the corrective action in step S03 (including the priority order if two or more corrective actions were decided) with the execution result. The result storage unit 122 may also record the timing at which the condition in which it was determined that bubbles were present in the processing liquid L was resolved as an execution result.

[0102] After step S07 is executed, the control device 100 returns to step S02. The control device 100 repeatedly executes the series of processes from step S02 onward, for example, until the operation of the wafer processing system 1 stops.

[0103] Figure 12 is a flowchart showing an example of a processing flow for adjusting the priority of response information. In this processing flow, the control device 100 first executes step S11. In step S11, for example, the operation adjustment unit 124 waits until the adjustment timing is reached. The adjustment timing is set in advance by an operator, such as a worker. The adjustment timing may be set to the extent that the number of times foam is detected and corresponding response actions are performed reaches a predetermined range.

[0104] Next, the control device 100 executes step S12. In step S12, for example, the operation adjustment unit 124 calculates a score value according to predetermined conditions for each combination of the results of acquiring monitoring information in the countermeasure information, based on the execution result information accumulated by the result storage unit 122. The operation adjustment unit 124 does not need to calculate a score value for combinations in which the number of countermeasure operations performed is less than the specified number, or for combinations in which the priority of countermeasure operations has not been determined, as these are excluded from adjustment. The conditions for calculating the score value are predetermined, and for example, the score value is set to be lower if the number of countermeasure operations performed is large or if foam removal is not achieved.

[0105] Next, the control device 100 executes step S13. In step S13, for example, the operation adjustment unit 124 determines whether there are any combinations in which the score value calculated in step S12 is below the standard. If, in step S13, the score value is greater than the standard for all combinations to be adjusted (step S13: NO), the control device 100 returns to step S11.

[0106] On the other hand, if there are combinations in step S13 whose score values ​​are below the standard (step S13: YES), the control device 100 proceeds to step S14. In step S14, for example, the priority of the actions taken to address combinations whose score values ​​are below the standard is changed. The method for changing the priority may be predetermined, or the priority may be changed based on instructions from an operator such as a worker.

[0107] After step S04 is executed, the control device 100 returns to step S11. The control device 100 repeatedly executes the series of processes from step S11 onward, for example, until the wafer processing system 1 is shut down. The control device 100 may also execute the series of processes from step S12 onward when the wafer processing system 1 is shut down for maintenance.

[0108] [Differentiation] The series of processes shown in Figures 10 and 12 are examples and can be modified as appropriate. In the above series of processes, one step and the next step may be executed in parallel, and some steps may be executed in a different order than the example above. In place of at least some of the steps in the above series of processes, or in addition to the above series of processes, steps with content different from the example above may be executed.

[0109] In the example described above, the control device 100 autonomously performs corrective actions based on its own judgment, but the control device 100 may present one or more corrective actions it has decided (selected) to an operator such as a worker. A monitor 102 may be connected to the control device 100, as shown in Figure 1 or Figure 6. The monitor 102 can be any type of display that can show information to the operator, such as a liquid crystal display.

[0110] The control device 100 may have an information display unit 126 as a functional block. The information display unit 126 displays one or more corrective actions determined by the action determination unit 116 on the monitor 102. In addition to one or more corrective actions, the information display unit 126 may also display at least one of the information acquired by the monitoring information acquisition unit 112 and the information indicating the determination result by the foam mixing determination unit 114 on the monitor 102. An operator, such as a worker, may check the results of the corrective actions displayed on the monitor 102 and decide which corrective actions to perform based on those results. An operator, such as a worker, may input information specifying the corrective actions to the control device 100, along with a user instruction to instruct the execution of the specified corrective actions.

[0111] The substrate processing method may include a display step. The display step is a step of displaying one or more corrective actions determined in the action determination step on the monitor 102. The display step is performed, for example, by the information display unit 126. When the display step is performed, the control step may involve the corrective action execution unit 120 controlling the processing liquid supply unit 60 to execute one or more corrective actions specified by user instructions.

[0112] In the above supply process, a metal-containing resist may be supplied to the surface Wa of the wafer W as the processing liquid L. That is, the processing liquid L discharged from the nozzle 70 toward the surface Wa of the wafer W may be a metal-containing resist. The processing liquid supply unit 60 that supplies the metal-containing resist to the surface Wa may have a gas atmosphere pipe 250 and a gas supply unit 260 (see Figure 4). The gas atmosphere pipe 250 is a pipe that surrounds at least a part of the supply pipe 69 and contains an inert gas Gn inside. The gas atmosphere pipe 250 is configured to surround at least a part of the outer wall of the supply pipe 69 and maintain a state in which the inert gas Gn is filled around its outer wall.

[0113] The gas supply unit 260 supplies inert gas Gn to the space formed by the gas atmosphere piping 250. The gas supply unit 260 may supply nitrogen gas as the inert gas Gn. The gas supply unit 260 may be able to adjust the amount of inert gas Gn supplied to the space formed by the gas atmosphere piping 250. By maintaining a state in which inert gas Gn is contained in the space around at least a part of the outer wall of the processing liquid supply unit 60, the effects on the metal-containing resist caused by exposure to the atmospheric atmosphere (effects due to moisture) can be reduced.

[0114] A metal-containing resist is one that contains metal as a component of the resist, and does not mean a resist that contains metal only as an impurity. A metal-containing resist is formed on the surface Wa of a wafer W, and the resist material that forms the resist film contains metal to which ligands and hydroxyl groups are bonded. The metal component of this resist may be selected from, for example, tin (Sn), tungsten (W), hafnium (Hf), zirconium (Zr), indium (In), tellurium (Te), antimony (Sb), nickel (Ni), cobalt (Co), titanium (Ti), tantalum (Ta), molybdenum (Mo), bismuth (Bi), iodine (I), germanium (Ge), and combinations thereof, and is not limited to the metal materials described above. The ligand is an organic compound such as ethyl, i-propyl, n-propyl, t-butyl, i-butyl, n-butyl, sec-butyl, n-pentyl, i-pentyl, t-pentyl, sec-pentyl, or alkyl, and the organic compound may be partially substituted with fluorine or halogen elements such as bromine or iodine. The ligand may also be a portion selected from the group consisting of the mixtures described above.

[0115] In metal-containing resists, exposure after film formation, primarily, leads to the cleavage of the bond between the metal and its ligand (i.e., ligand detachment), followed by the recombination of the metal with the oxygen atoms constituting the hydroxyl groups (metal recombination), and condensation reactions between the hydroxyl groups. Through this series of reactions, each metal exists in the resist pattern as an oxide. The aggregated metal oxides are bonded to each other via oxygen atoms, resulting in a stronger compound in the resist pattern than before oxide formation. The above description is an example illustrating the state of the negative development process; in the case of positive development, methods such as hydrophilization after exposure and alkaline development can be performed by utilizing the polarity change caused by exposure. The metal-containing resist according to this disclosure is not limited to the components described above, and may consist of other components; the reactions as a metal-containing resist are not limited to those described above. Furthermore, the method of forming the resist film is not limited to spin coating, but may also include CVD (chemical vapor deposition) or atomic layer deposition (ALD).

[0116] In one example, the gas atmosphere piping 250 is positioned between the discharge valve 74 and the nozzle 70 (section V) such that it surrounds at least a portion of the liquid supply pipe 72. In this case, when it is determined that bubbles are present in section V, the pressure inside the gas atmosphere piping 250 may be adjusted as a corrective action. The pressure inside the gas atmosphere piping 250 may be adjusted by adjusting the amount of inert gas Gn supplied by the gas supply unit 260. By lowering the pressure inside the gas atmosphere piping 250 (for example, the set pressure), the possibility of bubbles being generated in the processed liquid L due to the placement of the gas atmosphere piping 250 can be reduced.

[0117] If the action execution unit 120 determines that the action is to reduce the pressure inside the gas atmosphere piping 250, it may control the gas supply unit 260 so that the pressure inside the gas atmosphere piping 250 becomes the reduced set value. If the action execution unit 120 is continuously supplying the processing liquid L to the surface Wa of the wafer W, it may repeatedly alternately perform control to maintain the pressure at the reference set pressure and control to maintain the pressure at the reduced set pressure. The gas atmosphere piping 250 may be configured to create negative pressure inside it. For at least a portion of the time while the action is being performed, control may be performed so that the space inside the gas atmosphere piping 250 becomes negative pressure.

[0118] A separate computer from the control device 100 may have at least some of the various functional blocks illustrated in Figure 6. This separate computer may be connected to the control device 100 in a communicative manner. If it is determined that a defect caused by bubbles has occurred based on the image data from the inspection device U3, any of the corrective actions may be performed. In one of the various examples described above, at least some of the matters described in the other examples may be combined.

[0119] [Summary of this disclosure] This disclosure includes the configurations described in (1) to (13) below.

[0120] A substrate processing method comprising: (1) supplying a processing liquid (L) to the surface (Wa) of a substrate (W) using a liquid supply unit (60) having a nozzle (70) capable of discharging a processing liquid (L), a source (92) for supplying the processing liquid (L), and a supply pipe (69) connecting the nozzle (70) and the source (92); acquiring monitoring information at each of a plurality of monitoring points in the liquid supply unit (60) that can estimate whether or not bubbles are present in the processing liquid (L); and determining one or more countermeasures from a plurality of countermeasures for removing bubbles based on the monitoring information acquired at each of the plurality of monitoring points. In some cases, a method is used in which the presence of foam in the processing liquid (L) is detected from the state of the surface (Wa) after the processing liquid (L) has been supplied, and an operator such as a worker identifies the cause of the foam and takes countermeasures. In contrast, in the above substrate processing method, monitoring information is acquired at each of the multiple monitoring points that allows for the estimation of whether or not the processing liquid (L) and foam are mixed, and one or more countermeasures to remove the foam are determined based on this monitoring information. This eliminates some of the judgment and confirmation work performed by the operator such as a worker. Therefore, in the above substrate processing method, countermeasures to resolve problems caused by foam in liquid processing using processing liquid (L) can be easily implemented.

[0121] (2) The substrate processing method according to (1) above, further comprising controlling the liquid supply unit (60) to perform one or more determined corrective actions. In this case, one or more of the determined corrective actions are executed without the need for judgment or confirmation by an operator such as a worker. Therefore, it is possible to simplify the work required to resolve problems caused by foam.

[0122] (3) The substrate processing method described in (1) above, further comprising displaying one or more determined corrective actions on a monitor (102). In this case, operators such as workers can refer to the information displayed on the monitor (102) and decide on the actions to take to resolve the foam-related problem. Therefore, it is possible to simplify the work required to resolve foam-related problems.

[0123] (4) A substrate processing method according to any one of (1) to (3) above, further comprising: imaging the surface (Wa) of the substrate (W) after the processing liquid (L) has been supplied by the liquid supply unit (60); and detecting defects (d) caused by bubbles in the processing liquid (L) based on surface image data obtained by imaging the surface (Wa) of the substrate (W). In this case, even if the mixing of the processing liquid (L) and foam cannot be detected at multiple monitoring points for some reason, the processing liquid supply unit (60) can detect that the processing liquid (L) and foam are in a mixed state.

[0124] (5) In order to acquire monitoring information, nozzle image data is acquired by a camera (230) that images the inside or tip of the nozzle (70) as information that can estimate whether or not bubbles are present in the processing liquid (L) upstream of the tip of the nozzle (70), the substrate processing method according to any one of (1) to (4) above. If a mixture of processing liquid (L) and foam occurs upstream of the tip of the nozzle (70), the presence of foam will lower the liquid level of the processing liquid (L) inside the nozzle (70). By detecting this drop in liquid level from nozzle image data, it is possible to perform corrective actions to avoid problems such as the processing liquid (L) unintentionally falling from the nozzle (70) due to foam.

[0125] (6) In acquiring monitoring information, a plurality of sensors are used, which are arranged at different positions on the supply flow path formed by the supply pipe (69), to acquire monitoring information at each of the plurality of monitoring locations, wherein the plurality of sensors include at least one of a dissolved concentration sensor (210) that measures the dissolved concentration of a predetermined component in the processing liquid (L) and a bubble sensor (220) that detects bubbles in the processing liquid (L), the substrate processing method according to any one of (1) to (5) above. In this case, the state of mixing between the processing liquid (L) and foam can be detected more reliably, and it is possible to identify at which point in the flow path within the supply pipe (69) the foam is present.

[0126] (7) The substrate processing method according to (6) above, wherein the plurality of sensors include a dissolved concentration sensor (210) and a bubble sensor (220), the liquid supply unit (60) includes a liquid supply unit (80) which includes a filter (86) for collecting foreign matter contained in the processing liquid (L) in the supply channel and a pump (82) for sending the processing liquid (L) toward the nozzle (70), a discharge valve (74) for opening and closing the flow path between the liquid supply unit (80) and the nozzle (70) in the supply channel and a replenishment unit (90) for replenishing the processing liquid (L) from a supply source (92) to the liquid supply unit (80), and the dissolved concentration sensor (210) is located in a section of the supply channel upstream of the filter (86). The presence of foam detected by the dissolved concentration sensor (210) is often due to foam being mixed into the processing liquid (L) itself at the supply source (92). Therefore, by using the dissolved concentration sensor (210) in the section of the supply flow path within the supply piping (69) that is closest to the supply source (92), it is possible to detect the presence of foam more efficiently.

[0127] (8) A substrate processing method according to any one of (1) to (7) above, wherein, in supplying a processing liquid (L) to the surface (Wa) of the substrate (W), a metal-containing resist is supplied to the surface (Wa) of the substrate (W) as the processing liquid (L), and the liquid supply unit (60) is arranged to surround at least a part of the supply pipe (69) and further has a gas atmosphere pipe (250) containing an inert gas (Gn) inside, and the multiple processing operations include an operation to adjust the pressure inside the gas atmosphere pipe (250). Bubbles may form in the processing solution (L) due to the inert gas (Gn) in the gas atmosphere piping (250). In response to this, the above substrate processing method includes an operation to adjust the pressure in the gas atmosphere piping (250) as one of the countermeasures. This makes it possible to reduce the influence of the inert gas (Gn) in the gas atmosphere piping (250) on the metal-containing resist and to suppress problems caused by bubbles.

[0128] (9) In determining one or more corrective actions, the substrate processing method according to any one of (1) to (8) above, wherein one or more corrective actions are selected from among multiple corrective actions according to corrective information which associates a combination of the results of acquiring monitoring information at multiple monitoring points with a combination of actions for removing bubbles. In this case, it is possible to simplify the calculation process for determining one or more corrective actions.

[0129] (10) The substrate processing method described in (9) above, wherein in the countermeasure information, at least a portion of the combination of the results of acquiring monitoring information at multiple monitoring locations is associated with two or more actions for removing bubbles, and a priority order for the two or more actions is defined, and when determining one or more countermeasure actions, if two or more actions are selected, the execution order of the two or more actions is also determined according to the countermeasure information. When performing two or more corrective actions, it is sometimes more efficient to perform them sequentially rather than at approximately the same time. The above method also determines the execution order, making it possible to further simplify the process of resolving problems caused by foam.

[0130] (11) The substrate processing method described in (10) above, further comprising: (11) storing the results of executing one or more determined countermeasures as execution result information; and changing the priority order defined in the countermeasure information based on the stored execution result information. In this case, priorities are changed based on past performance, so more efficient priorities are determined in the troubleshooting process. Therefore, it becomes possible to efficiently carry out countermeasures to resolve problems caused by foam.

[0131] (12) A computer-readable storage medium storing a program for causing the apparatus to execute any one of the substrate processing methods described in (1) to (11) above. This storage medium allows for easy implementation of countermeasures to resolve problems caused by bubbles during liquid processing using the processing solution (L), similar to the substrate processing method described above.

[0132] (13) A substrate processing apparatus (1) comprising: a liquid supply unit (60) that supplies the processing liquid (L) to the surface (Wa) of a substrate (W), having a nozzle (70) capable of discharging a processing liquid (L), a source (92) for supplying the processing liquid (L), and a supply pipe (69) connecting the nozzle (70) and the source (92); a monitoring unit (200) that acquires monitoring information capable of estimating whether or not bubbles are present in the processing liquid (L) at each of a plurality of monitoring points in the liquid supply unit (60); and an operation determination unit (116) that determines one or more countermeasures from a plurality of countermeasures for removing bubbles based on the monitoring information acquired at each of the plurality of monitoring points. In this substrate processing apparatus (1), similar to the substrate processing method described above, it is possible to easily implement measures to resolve problems caused by foam during liquid processing using the processing liquid (L). [Explanation of symbols]

[0133] 1...Wafer processing system, W...Wafer, Wa...Surface, U1...Liquid processing device, L...Processing liquid, 60...Processing liquid supply unit, 69...Supply piping, 70...Nozzle, 74...Discharge valve, 80...Liquid delivery unit, 82...Pump, 86...Filter, 90...Replenishment unit, 92...Supply source, U3...Inspection device, 100...Control device, 102...Monitor, 112...Monitoring information acquisition unit, 116...Operation decision unit, 120...Response execution unit, 200...Monitoring system, 210...Dissolved concentration sensor, 220...Bubble sensor, 230...Nozzle camera, 250...Gas atmosphere piping, Gn...Inert gas.

Claims

1. A liquid supply unit having a nozzle capable of discharging the processing liquid, a source for supplying the processing liquid, and a supply pipe connecting the nozzle and the source, supplies the processing liquid to the surface of the substrate. In each of the multiple monitoring locations in the liquid supply unit, monitoring information is acquired that allows for the estimation of whether or not foam is present in the processing liquid. Based on the monitoring information acquired at each of the aforementioned multiple monitoring locations, one or more countermeasures are selected from among multiple countermeasures for removing foam. A substrate processing method, including the following.

2. The further includes controlling the liquid supply unit to perform one or more of the determined countermeasures, The substrate processing method according to claim 1.

3. The further includes displaying the one or more determined corrective actions on a monitor. The substrate processing method according to claim 1.

4. The surface of the substrate after the processing liquid has been supplied by the liquid supply unit is imaged, The further includes detecting defects caused by bubbles in the processing liquid based on surface image data obtained by imaging the surface of the substrate, The substrate processing method according to claim 1.

5. In acquiring the aforementioned monitoring information, nozzle image data is acquired by a camera that images the inside or tip of the nozzle, as information that can estimate whether or not bubbles are present in the processing liquid upstream of the nozzle tip. A substrate processing method according to any one of claims 1 to 4.

6. In acquiring the aforementioned monitoring information, a plurality of sensors are used, each of which is positioned at different locations on the supply path formed by the supply piping, to acquire the monitoring information at each of the plurality of monitoring locations. The plurality of sensors include at least one of a dissolved concentration sensor for measuring the dissolved concentration of a predetermined component in the processing liquid and a bubble sensor for detecting bubbles in the processing liquid. A substrate processing method according to any one of claims 1 to 4.

7. The plurality of sensors include the dissolved concentration sensor and the bubble sensor, The aforementioned liquid supply unit is A liquid supply unit including a filter for collecting foreign matter contained in the processing liquid in the supply channel and a pump for sending the processing liquid toward the nozzle, A discharge valve that opens and closes the flow path between the liquid delivery section and the nozzle in the supply flow path, It has a replenishment unit that replenishes the processing liquid from the supply source to the liquid supply unit, The dissolved concentration sensor is located in the section of the supply channel upstream of the filter. The substrate processing method according to claim 6.

8. In supplying the processing solution to the surface of the substrate, a metal-containing resist is supplied to the surface of the substrate as the processing solution. The liquid supply unit is arranged to surround at least a portion of the supply piping and further includes a gas atmosphere piping that contains an inert gas inside. The aforementioned multiple corrective actions include actions to adjust the pressure in the gas atmosphere piping. A substrate processing method according to any one of claims 1 to 4.

9. In determining the one or more countermeasures described above, one or more countermeasures are selected from the multiple countermeasures according to countermeasures information that associates the combination of the results of acquiring the monitoring information at the multiple monitoring locations with the combination of actions for removing foam. A substrate processing method according to any one of claims 1 to 4.

10. In the aforementioned countermeasure information, at least a portion of the combinations of the results of acquiring the monitoring information at the multiple monitoring locations are associated with two or more actions for removing foam, and a priority order for these two or more actions is defined. In determining the one or more corrective actions described above, if two or more actions are selected, the execution order of those two or more actions is also determined according to the corrective information. The substrate processing method according to claim 9.

11. The results of executing the one or more actions determined above are stored as execution result information, This further includes changing the priority specified in the action information based on the accumulated execution result information, The substrate processing method according to claim 10.

12. A computer-readable storage medium storing a program for causing an apparatus to execute the substrate processing method described in any one of claims 1 to 4.

13. A liquid supply unit having a nozzle capable of discharging a processing liquid, a source for supplying the processing liquid, and a supply pipe connecting the nozzle and the source for supplying the processing liquid to the surface of a substrate, A monitoring unit that acquires monitoring information capable of estimating whether or not foam is present in the processing liquid at each of the multiple monitoring locations in the liquid supply unit, Based on the monitoring information acquired at each of the aforementioned multiple monitoring locations, an action determination unit determines one or more countermeasures from among multiple countermeasures for removing foam, A substrate processing apparatus comprising:

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