Substrate processing apparatus, inference method of substrate processing, and storage medium

Abstract

A substrate processing apparatus capable of quickly adjusting a removal width of a coating film formed on a substrate, an inference method of substrate processing, and a storage medium are provided. The substrate processing apparatus includes: a peripheral removal section that removes a peripheral portion of a coating film formed on a surface of a substrate; a distribution acquisition section that acquires a removal width distribution indicating a relationship between a position in a circumferential direction of the substrate and a width of a portion of the substrate from which the coating film is removed; and a cause inference section that outputs cause information indicating a cause of an error in the width based on the removal width distribution.

Description

Technical Field

[0001] This invention relates to a substrate processing apparatus, a substrate processing inference method, and a storage medium. Background Technology

[0002] Patent Document 1 discloses a coating film removal method, which includes: a coating film removal step in which solvent is supplied from a solvent nozzle to the periphery of the coating film on the surface of the substrate while rotating a circular substrate about its orthogonal axis, thereby removing the coating film in a ring shape with a predetermined width dimension; a step in which the substrate is conveyed to an inspection module for inspecting the state of the coating film by photographing the entire surface of the substrate; a step in which the removed area of ​​the coating film is detected based on the image data acquired by the inspection module; and a step in which the subsequent substrate junction position is corrected based on the detection result.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent document 1: Japanese Patent Application Publication No. 2014-91105. Summary of the Invention

[0006] The problem the invention aims to solve

[0007] The present invention provides a substrate processing apparatus that enables rapid adjustment of the removal width of a coating formed on a substrate.

[0008] Technical means for solving problems

[0009] A substrate processing apparatus of one side of the present invention includes: a peripheral removal unit that removes peripheral portions of a coating formed on the surface of a substrate; a distribution acquisition unit that acquires a removal width distribution representing the relationship between the circumferential position of the substrate and the width of the portion of the substrate in which the coating has been removed; and a cause inference unit that outputs cause information representing the cause of an error in the width based on the removal width distribution.

[0010] Invention Effects

[0011] According to the present invention, a substrate processing apparatus is provided that enables rapid adjustment of the removal width of a coating formed on a substrate. Attached Figure Description

[0012] Figure 1 This is a schematic diagram illustrating the general structure of a substrate processing system.

[0013] Figure 2 This is a schematic diagram illustrating the general structure of a coating unit.

[0014] Figure 3 This is a schematic diagram illustrating the general structure of the inspection unit.

[0015] Figure 4 This is a schematic diagram illustrating the functional structure of the control unit.

[0016] Figure 5 This is a schematic diagram illustrating the hardware structure of the control unit.

[0017] Figure 6 This is a flowchart illustrating the film formation control steps.

[0018] Figure 7 This is a flowchart illustrating the steps for obtaining the distribution.

[0019] Figure 8 This is a flowchart illustrating the steps for outputting cause information.

[0020] Explanation of reference numerals in the attached figures

[0021] 2… Coating and developing apparatus (substrate processing apparatus), 20… Rotation holding unit, 31, 41… Nozzle, 115… Distribution acquisition unit, 116… Feature quantity calculation unit, 121… Evaluation unit, 122… Contribution evaluation unit, 124… Cause inference unit, U1… Coating unit (peripheral removal unit), W… Substrate, Wa… Surface. Detailed Implementation

[0022] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used to refer to the same elements or elements having the same function, and repeated descriptions are omitted.

[0023] (Substrate processing system)

[0024] The substrate processing system 1 is a system for forming a photosensitive coating on a substrate, exposing the photosensitive coating, and developing the photosensitive coating. Examples of substrates that can be processed include semiconductor wafers, glass substrates, mask substrates, or FPDs (Flat Panel Displays). A substrate includes a semiconductor wafer or similar material on which a coating has already been formed in a previous processing step.

[0025] like Figure 1 As shown, the substrate processing system 1 includes a coating and developing apparatus 2 and an exposure apparatus 3. The exposure apparatus 3 performs an exposure process on a resist film (photosensitive coating) formed on a substrate W. The substrate W is, for example, circular, and has position indicators (e.g., notches) at its periphery as a reference for its circumferential position. Specifically, the exposure apparatus 3 irradiates the exposed portion of the resist film with energy rays using methods such as immersion exposure. The coating and developing apparatus 2 performs a process to form a resist film on the surface of the substrate W before the exposure process of the exposure apparatus 3, and performs a development process on the resist film after the exposure process.

[0026] (Substrate processing device)

[0027] The structure of the coating and developing apparatus 2 will be described below as an example of a substrate processing apparatus. The coating and developing apparatus 2 includes a carrier block 4, a processing block 5, an interface block 6, and a control unit 100.

[0028] The carrier block 4 handles the introduction of substrate W into the coating and developing apparatus 2 and the removal of substrate W from the coating and developing apparatus 2. For example, the carrier block 4 can support multiple carriers C (receiving sections) for substrate W and has a built-in transfer arm A1. The carriers C, for example, receive multiple circular substrates W. The transfer arm A1 removes the substrate W from the carrier C and transfers it to the processing block 5, receives the substrate W from the processing block 5 and returns it to the carrier C.

[0029] Processing block 5 has multiple processing modules 11, 12, 13, and 14. Processing module 11 has multiple coating units U1, multiple heat treatment units U2, and a conveyor arm A3 for conveying the substrate W to these units.

[0030] Processing module 11 forms a lower layer film on the surface of substrate W through coating unit U1 and heat treatment unit U2. Coating unit U1 applies a processing solution for lower layer film formation to substrate W. Heat treatment unit U2 performs various heat treatments accompanying the formation of the lower layer film. Heat treatment unit U2, for example, includes a hot plate and a cooling plate. The hot plate heats the substrate W, and the cooling plate cools the heated substrate W to perform heat treatment.

[0031] Processing module 12 (film formation unit) includes multiple coating units U1, multiple heat treatment units U2, multiple inspection units U3, and a transport arm A3 for transporting the substrate W to these units. Processing module 12 forms a resist film on the lower layer film using the coating units U1 and the heat treatment units U2. The coating unit U1 forms a coating on the surface of the substrate W by applying a processing liquid for resist film formation onto the lower layer film. Hereinafter, this coating is referred to as the "pre-baking resist film." The heat treatment unit U2 performs various heat treatments accompanying the formation of the resist film. Thus, the pre-baking resist film becomes the resist film.

[0032] The coating unit U1 may also be configured to remove at least a portion of the resist film. The step of removing at least a portion of the resist film includes removing a portion of the pre-baking resist film before heat treatment in the heat treatment unit U2. For example, after the coating unit U1 forms a pre-baking resist film on the surface of the substrate W, the peripheral portion of the pre-baking resist film is removed by supplying a removal liquid to the periphery of the substrate W.

[0033] The inspection unit U3 performs processing to inspect the state of the surface Wa of the substrate W. For example, the inspection unit U3 obtains information indicating the state of the surface Wa of the substrate W. The information indicating the state of the surface Wa includes information about the width of the portion of the substrate W where the resist film has been removed (e.g., the radial width of the substrate W).

[0034] Processing module 13 incorporates multiple coating units U1, multiple heat treatment units U2, and a conveying arm A3 for transporting the substrate W to these units. Processing module 13 forms an upper film on the resist film using the coating units U1 and heat treatment units U2. The coating units U1 of processing module 13 apply a liquid for upper film formation onto the resist film. The heat treatment units U2 of processing module 13 perform various heat treatments accompanying the formation of the upper film.

[0035] Processing module 14 incorporates multiple developing units U4, multiple heat treatment units U5, and a transport arm A3 for conveying the substrate W to these units. Processing module 14 performs development treatment on the exposed resist film using the developing units U4 and heat treatment units U5. The developing unit U4 develops the resist film by applying a developer solution to the surface of the exposed substrate W and then rinsing it with a rinsing solution. The heat treatment unit U5 performs various heat treatments accompanying the development process. Specific examples of heat treatment include pre-development heat treatment (PEB: Post Exposure Bake) and post-development heat treatment (PB: Post Bake).

[0036] A shelf unit U10 is provided on the side of the carrier block 4 within the processing block 5. The shelf unit U10 is divided into multiple small compartments arranged in the vertical direction. A lifting arm A7 is provided near the shelf unit U10. The lifting arm A7 causes the substrate W to move up and down between the compartments of the shelf unit U10.

[0037] A shelf unit U11 is provided on one side of the interface block 6 within the processing block 5. The shelf unit U11 is divided into multiple small compartments arranged in the vertical direction.

[0038] Interface block 6 facilitates the transfer of substrate W between itself and exposure device 3. For example, interface block 6 has a built-in transfer arm A8 connected to exposure device 3. Transfer arm A8 transfers substrate W, which is disposed in shelf unit U11, to exposure device 3, and after receiving substrate W from exposure device 3, returns it to shelf unit U11.

[0039] The control unit 100 controls, for example, the various elements included in the coating and developing apparatus 2. Hereinafter, a series of control steps performed by the control unit 100 on a substrate W are illustrated. For example, the control unit 100 first controls the transfer arm A1 to transport the substrate W in the carrier C to the shelf unit U10, and controls the lifting arm A7 to place the substrate W into the chamber for the processing module 11.

[0040] Next, the control unit 100 controls the conveyor arm A3 to convey the substrate W from the shelf unit U10 to the coating unit U1 and heat treatment unit U2 within the processing module 11. Furthermore, the control unit 100 controls the coating unit U1 and heat treatment unit U2 to form a lower film on the surface of the substrate W. Afterward, the control unit 100 controls the conveyor arm A3 to return the substrate W with the lower film formed to the shelf unit U10, and controls the lifting arm A7 to position the substrate W into the chamber of the processing module 12.

[0041] Next, the control unit 100 controls the conveyor arm A3 to convey the substrate W of the shelf unit U10 to the coating unit U1 and heat treatment unit U2 within the processing module 12. Furthermore, the control unit 100 controls the coating unit U1 and heat treatment unit U2 to form a resist film on the lower film of the substrate W. For example, the control unit 100 controls the coating unit U1 to form the aforementioned pre-baking resist film on the lower film of the substrate W, removes the peripheral portion of the pre-baking resist film, and controls the heat treatment unit U2 to perform heat treatment on the substrate W to transform the pre-baking resist film into a resist film.

[0042] Next, the control unit 100 controls the conveyor arm A3 to convey the substrate W to the inspection unit U3, and obtains information from the inspection unit U3 indicating the state of the surface of the substrate W. Afterwards, the control unit 100 controls the conveyor arm A3 to send the substrate W back to the shelf unit U10, and controls the lifting arm A7 to place the substrate W into the chamber for the processing module 13.

[0043] Next, the control unit 100 controls the conveyor arm A3 to convey the substrate W of the shelf unit U10 to each unit in the processing module 13, and controls the coating unit U1 and the heat treatment unit U2 to form an upper film on the resist film of the substrate W. Afterwards, the control unit 100 controls the conveyor arm A3 to convey the substrate W to the shelf unit U11.

[0044] Next, the control unit 100 controls the transfer arm A8 to deliver the substrate W from the shelf unit U11 to the exposure apparatus 3. After that, the control unit 100 controls the transfer arm A8 to receive the substrate W after exposure processing from the exposure apparatus 3 and place it into the chamber of the processing module 14 in the shelf unit U11.

[0045] Next, the control unit 100 controls the conveyor arm A3 to transport the substrate W from the shelf unit U11 to the developing unit U4 and the heat treatment unit U5 within the processing module 14, and controls the developing unit U4 and the heat treatment unit U5 to perform developing treatment on the resist film of the substrate W. Afterwards, the control unit 100 controls the conveyor arm A3 to return the substrate W to the shelf unit U10, and controls the lifting arm A7 and the transfer arm A1 to return the substrate W to the carrier C. This completes the series of control steps for one substrate W.

[0046] (Coating Unit)

[0047] Next, an example of the structure of the coating unit U1 in the processing module 12 will be described in detail. As described above, the coating unit U1 supplies a processing liquid for forming a resist film to the surface Wa of the substrate W to form the aforementioned pre-baking resist film. In addition, after the coating unit U1 (peripheral removal section) forms the pre-baking resist film on the surface Wa of the substrate W, it removes the peripheral portion of the pre-baking resist film by supplying a removal liquid to the periphery of the substrate W.

[0048] like Figure 2 As shown, the coating unit U1 includes a rotating holding section 20, a processing liquid supply section 30, and a removal liquid supply section 40. The rotating holding section 20 holds the substrate W and rotates it. For example, the rotating holding section 20 includes a holding section 21 and a rotating drive section 22. The holding section 21 supports the substrate W, which is horizontally arranged with its surface Wa facing upward, and holds the substrate W by adsorption (e.g., vacuum adsorption). The rotating drive section 22, for example, uses an electric motor as a power source to rotate the holding section 21 about a vertical rotation center CL. As a result, the substrate W rotates.

[0049] The processing liquid supply unit 30 supplies processing liquid for resist film formation to the surface Wa of the substrate W. For example, the processing liquid supply unit 30 includes a nozzle 31, a liquid source 32, a liquid delivery unit 33, and a nozzle moving unit 34. The nozzle 31 discharges processing liquid onto the surface Wa of the substrate W. The liquid source 32 collects the processing liquid and pumps it to the nozzle 31. The liquid delivery unit 33 guides the processing liquid from the liquid source 32 to the nozzle 31. For example, the liquid delivery unit 33 includes a liquid delivery line L1 and a valve V1. The liquid delivery line L1 connects the liquid source 32 and the nozzle 31. The valve V1 is, for example, an air valve, which opens and closes the flow path within the liquid delivery line L1. The nozzle moving unit 34, powered by a motor or similar source, moves the nozzle 31 between its rotation center CL and the area outside the substrate W.

[0050] The removal liquid supply unit 40 supplies removal liquid to the surface Wa of the substrate W. The removal liquid is a solvent capable of removing (dissolving) the resist film formed by the processing liquid supplied from the processing liquid supply unit 30 before baking. Specific examples of the removal liquid include organic solvents such as diluents. For example, the removal liquid supply unit 40 includes a nozzle 41, a liquid source 42, a liquid delivery unit 43, a flow sensor 45, and a nozzle moving unit 44.

[0051] Nozzle 41 discharges removal liquid to the periphery of the substrate W, which is held and rotated by the rotating holding part 20. Nozzle 41 discharges removal liquid to the surface Wa of the substrate W, which is rotating by the rotating holding part 20. Liquid source 42 collects removal liquid and pressurizes it towards nozzle 41. Liquid delivery part 43 guides removal liquid from liquid source 42 to nozzle 41. For example, liquid delivery part 43 has a liquid delivery line L2 and a valve V2. Liquid delivery line L2 connects liquid source 42 and nozzle 41. Valve V2 is, for example, an air valve, which opens and closes the flow path in liquid delivery line L2. Flow sensor 45 detects the flow rate (flow rate per unit time) of removal liquid in liquid delivery line L2. Nozzle moving part 44 moves nozzle 41 between the periphery of substrate W and the area outside substrate W by a power source such as an electric motor.

[0052] (Inspection Unit)

[0053] Next, an example of the structure of the inspection unit U3 will be described in detail. The inspection unit U3 acquires image data by photographing the surface Wa of the substrate W, which serves as surface information representing the state of the surface Wa. For example... Figure 3 As shown, the inspection unit U3 has a holding part 51, a rotation drive part 52, a position index detection part 53, and an imaging part 57.

[0054] The holding part 51 supports a substrate W that is horizontally arranged with its surface Wa facing upwards, and holds the substrate W by adsorption (e.g., vacuum adsorption). The rotation drive part 52, for example, uses a power source such as an electric motor to rotate the holding part 51 about a vertical rotation center. As a result, the substrate W rotates.

[0055] The position indicator detection unit 53 detects a notch in the substrate W. For example, the position indicator detection unit 53 includes a light-emitting unit 55 and a light-receiving unit 56. The light-emitting unit 55 emits light towards the periphery of the rotating substrate W. For example, the light-emitting unit 55 is positioned above the periphery of the substrate W and emits light downwards. The light-receiving unit 56 receives the light emitted by the light-emitting unit 55. For example, the light-receiving unit 56 is positioned below the periphery of the substrate W, opposite to the light-emitting unit 55.

[0056] The imaging unit 57 is a camera that captures at least the peripheral portion of the surface Wa of the substrate W. For example, the imaging unit 57 captures the peripheral portion of the surface Wa of the substrate W where no resist film has been formed (the resist film before baking has been removed). For example, the imaging unit 57 is positioned above the peripheral portion of the substrate W held by the holding unit 51 and faces downward.

[0057] (Control Department)

[0058] The aforementioned coating unit U1 and inspection unit U3 are controlled by the control unit 100. The control steps performed by the control unit 100 for the coating unit U1 and inspection unit U3 include: a step of having the coating unit U1 remove the peripheral portion of the resist film formed on the surface Wa of the substrate W; a step of obtaining from the inspection unit U3 a removal width distribution indicating the relationship between the circumferential position of the substrate W and the width (hereinafter referred to as "removal width") of the portion of the substrate W where the resist film has been removed; and a step of outputting cause information indicating the cause of the removal width error based on the removal width distribution. The error refers to a deviation from a specified target value.

[0059] Removal width errors can occur due to various reasons; however, determining the cause of the error solely based on error evaluation results is time-consuming. In this regard, the removal width distribution, which represents the relationship between the circumferential position of the substrate W and the removal width, tends to exhibit different characteristics depending on the cause of the error. Therefore, reliable causal information can be output based on the removal width distribution.

[0060] The following is for reference Figure 4 Specifically, the structure of the control unit 100 used to control the coating unit U1 and the inspection unit U3 is illustrated. For example... Figure 4 As shown, the control unit 100, as a functional structural element (hereinafter referred to as a "functional block"), includes a transport control unit 111, a film formation control unit 112, a peripheral removal control unit 113, a program storage unit 114, a distribution acquisition unit 115, a feature quantity calculation unit 116, a candidate cause storage unit 123, a device status acquisition unit 117, a record generation unit 118, and a data storage unit 119.

[0061] The transport control unit 111 controls the transport arm A3 to transport the substrate W based on the operation program stored in the program storage unit 114. The operation program of the transport arm A3 includes commands with timing defined by at least one control parameter. Specific examples of the at least one control parameter include the target transport position of the substrate W and the speed at which it moves towards that target position.

[0062] The film formation control unit 112 controls the coating unit U1 to form a pre-baking resist film on the surface of the substrate W based on the operation program stored in the program storage unit 114. The peripheral removal control unit 113 controls the coating unit U1 to remove the peripheral portion of the pre-baking resist film based on the operation program stored in the program storage unit 114.

[0063] The operation program of the coating unit U1 includes timing commands defined by at least one control parameter. Specific examples of the at least one control parameter include: the discharge rate (discharge per unit time) of the treatment liquid from the nozzle 31 for forming the resist film, the position of the nozzle 41 when discharging the removal liquid (e.g., the distance from the rotation center CL to the center of the nozzle 41), and the discharge rate (discharge per unit time) of the removal liquid from the nozzle 41. The opening degree of valve V1 can also be determined instead of the discharge rate of the treatment liquid from the nozzle 31, and the opening degree of valve V2 can also be determined instead of the discharge rate of the removal liquid from the nozzle 41.

[0064] The distribution acquisition unit 115 acquires from the inspection unit U3 the removal width distribution, which represents the relationship between the circumferential position of the substrate W and the width of the portion of the substrate W where the resist film has been removed (the removal width). The circumferential position of the substrate W refers to the position based on the position index detected by the position index detection unit 53, and is expressed, for example, by the angle around the center of the substrate W. The width of the portion where the resist film has been removed is, for example, the radial width of the substrate W. The removal width distribution can be a discrete dot matrix data representing the relationship between the circumferential position of the substrate W and the removal width, or it can be a continuous function data representing the relationship between the circumferential position of the substrate W and the removal width.

[0065] The feature quantity calculation unit 116 calculates multiple types of feature quantities associated with at least one error cause based on the removal width distribution. These multiple types of feature quantities include an evaluation value for the removal width, an evaluation value for the deviation (eccentricity) of the resist film periphery relative to the substrate W periphery, an evaluation value for the roundness of the resist film periphery, and an evaluation value for the roughness of the resist film periphery. The evaluation value for the removal width is, for example, a value representing the overall tendency of the removal width distribution. Specific examples of such evaluation values ​​include the average, median, etc.

[0066] The feature calculation unit 116 calculates an approximate function of the shape of the resist film with the center of the substrate W as the origin based on the width distribution of the removed material, and calculates the evaluation values ​​of the aforementioned deviation, the evaluation value of roundness, and the evaluation value of roughness based on the function.

[0067] The multiple types of feature quantities calculated by the feature quantity calculation unit 116 are each associated with at least one error cause in the candidate cause storage unit 123. The multiple types of feature quantities may include composite feature quantities associated with multiple types of error causes.

[0068] As an example, the evaluation value of the width is associated in the candidate cause storage unit 123 with at least the positional offset of the nozzle 41 and the change in the discharge amount of the removal liquid from the nozzle 41, where the change refers to a long-term change that occurs over a period longer than the processing period of a substrate W.

[0069] The deviation evaluation value in the candidate cause storage unit 123 is at least related to the positional offset of the substrate W on the rotating holding unit 20; the roundness evaluation value is at least related to the deformation of the substrate W and the deformation of the rotating holding unit 20; and the roughness evaluation value is at least related to the liquid splashing of the removal liquid and the variation in the discharge amount of the removal liquid from the nozzle 41. Here, variation refers to variation during the processing of one substrate W. The width evaluation value, roundness evaluation value, and roughness evaluation value, which are associated with at least two error causes, correspond to the aforementioned composite characteristic quantities.

[0070] The device status acquisition unit 117 acquires information indicating the operating status of at least the devices involved in the formation of the resist film, such as the conveyor arm A3 and the coating unit U1. For example, the device status acquisition unit 117 acquires the placement position of the substrate W in the coating unit U1 by the conveyor arm A3 (the position of the substrate W on the rotation holding unit 20), the placement position of the nozzle 41 when removing the resist film before baking, and the discharge amount of the removal liquid from the nozzle 41 when removing the resist film before baking (e.g., the flow rate detected by the flow sensor 45), etc.

[0071] The record generation unit 118 generates a record containing the calculation result of one feature quantity and the state of the coating unit U1 corresponding to that feature quantity, and saves it in the data storage unit 119. Here, "corresponding" means corresponding to the same substrate W. The state of the coating unit U1 corresponding to that feature quantity refers to the state of the coating unit U1 during the process of removing the pre-baking resist from the substrate W to which the feature quantity is calculated.

[0072] The state of the coating unit U1 includes at least the position of the substrate W on the rotating holding part 20 (the position of the center of the substrate W relative to the rotation center CL of the holding part 21), the position of the nozzle 41 when discharging the removal liquid, the amount of removal liquid discharged from the nozzle 41, and the variation range of the amount of removal liquid discharged from the nozzle 41. Here, the variation range refers to the variation range during the processing of one substrate W. The data storage unit 119 stores the records generated by the record generation unit 118.

[0073] The control unit 100 also includes an evaluation unit 121, a contribution evaluation unit 122, and a cause inference unit 124. The evaluation unit 121 evaluates the removal width based on the removal width distribution. The evaluation result of the removal width by the evaluation unit 121 can include multiple types of evaluation values. For example, the evaluation result of the removal width by the evaluation unit 121 can include the maximum and minimum values ​​of the removal width in the removal width distribution, or it can include the maximum, average, and minimum values ​​of the removal width in the removal width distribution.

[0074] The contribution evaluation unit 122 evaluates the contribution of multiple types of feature quantities to the error based on the calculation results of these feature quantities. Contribution is a value representing the degree of influence on the error. Contribution can be calculated using known statistical methods.

[0075] The cause inference unit 124 outputs cause information indicating the cause of the error in the width removal based on the width distribution. The means of outputting this information include displaying it on the display device 196 (described later) and sending the cause information to other devices. The means of outputting this information also include, as described later, the parameter adjustment unit 125, outputting the cause information to a function block that performs further processing based on the cause information.

[0076] The cause inference unit 124 can output cause information based on the calculation results of multiple types of feature quantities. The cause inference unit 124 can also output cause information based on the contribution of multiple types of feature quantities to the error. The cause inference unit 124 can output cause information based on at least one error cause among multiple types of error causes that is associated with at least the feature quantity with the largest contribution. For example, the cause inference unit 124 outputs cause information representing an error cause that is associated with at least the feature quantity with the largest contribution.

[0077] The cause inference unit 124 can also output cause information representing the contribution degree and at least one corresponding error cause for each of the multiple types of feature quantities. Based on this cause information, in addition to indicating the error cause associated with the feature quantity with the largest contribution, it can also indicate how much larger the contribution degree of this error cause is compared to the contribution degrees of other error causes.

[0078] Furthermore, the cause inference unit 124 can also output cause information indicating which of the multiple types of feature quantities has the greatest contribution. When it is known to the user which error cause each of the multiple types of feature quantities is associated with, the error cause is indicated by indicating which of the multiple types of feature quantities has the greatest contribution.

[0079] The cause inference unit 124 can also output cause information indicating the contribution of each of the multiple types of feature quantities. Based on this cause information, in addition to indicating the feature quantity with the largest contribution, it can also indicate how much larger the contribution of that feature quantity is compared to the contributions of other error causes.

[0080] When the feature quantity contributing the most is a composite feature quantity, the cause inference unit 124 can output cause information based on multiple types of error causes associated with that composite feature quantity and the state of the coating unit U1. Here, the state of the coating unit U1 refers to the state of the coating unit U1 corresponding to that composite feature quantity. "Corresponding" means associated with the same substrate W. The state of the coating unit U1 corresponding to that composite feature quantity refers to the state of the coating unit U1 during the process of removing the pre-baking resist from the substrate W, the object of calculation for that composite feature quantity.

[0081] For example, if the feature quantity with the greatest contribution is a composite feature quantity, the cause inference unit 124 can evaluate the correlation level between each of the multiple types of error causes and the composite feature quantity based on the records stored in the data storage unit 119, and output cause information based on the evaluation results of the correlation level.

[0082] The cause inference unit 124 can evaluate the correlation level between various types of error causes and composite feature quantities based on a predetermined number of records, including the latest record, stored in the data storage unit 119. For example, the cause inference unit 124 outputs cause information for error causes that indicate a higher correlation level with composite feature quantities.

[0083] As an example, when the feature quantity contributing the most is the width evaluation value, the cause inference unit 124 evaluates the correlation level between the position of nozzle 41 and the width evaluation value (hereinafter referred to as "first correlation level") and the correlation level between the discharge volume of the removed liquid from nozzle 41 and the width evaluation value (hereinafter referred to as "second correlation level") based on a series of records of the aforementioned predetermined number. For example, the first correlation level represents the correlation level between the positional offset of nozzle 41 and the width evaluation value. For example, the second correlation level represents the correlation level between the change in the discharge volume of the removed liquid from nozzle 41 and the width evaluation value.

[0084] If the first correlation level is higher than the second correlation level, the cause inference unit 124 outputs cause information indicating that the positional deviation of the nozzle 41 is the most likely cause of the error. If the second correlation level is higher than the first correlation level, the cause inference unit 124 outputs cause information indicating that the change in the discharge volume of the removal liquid from the nozzle 41 is the most likely cause of the error.

[0085] When the feature quantity contributing the most to the error is the roughness evaluation value, the cause inference unit 124 evaluates the correlation level (hereinafter referred to as "third correlation level") between the variation in the discharge amount of the removal liquid from the nozzle 41 and the roughness evaluation value based on a series of records of the aforementioned predetermined number. If the third correlation level exceeds the predetermined level, the cause inference unit 124 outputs cause information indicating that the variation in the discharge amount of the removal liquid is the most likely cause of the error. If the third correlation level is less than the predetermined level, the cause inference unit 124 outputs cause information indicating that liquid splashing of the removal liquid is the most likely cause of the error.

[0086] The cause inference unit 124 may output cause information if the evaluation result of the removal width from the evaluation unit 121 is outside the specified range, and omit the output of cause information if the evaluation result of the removal width from the evaluation unit 121 is within the specified range. For example, the cause inference unit 124 may output cause information if the maximum value of the removal width exceeds the upper limit of the specified range or if the minimum value of the removal width is lower than the lower limit of the specified range, and omit the output of cause information if both the maximum and minimum values ​​of the removal width are within the specified range.

[0087] Correspondingly, the contribution evaluation unit 122 can calculate the contribution if the evaluation result of the removal width from the evaluation unit 121 is outside the specified range, and omit the calculation of the contribution if the evaluation result of the removal width from the evaluation unit 121 is within the specified range. For example, the contribution evaluation unit 122 can calculate the contribution if the maximum value of the removal width exceeds the upper limit of the specified range or if the minimum value of the removal width is lower than the lower limit of the specified range, and omit the calculation of the contribution if both the maximum and minimum values ​​of the removal width are within the specified range.

[0088] The control unit 100 may also include a parameter adjustment unit 125. The parameter adjustment unit 125 adjusts at least one control parameter in the action program stored in the program storage unit 114 based on the cause information. For example, the parameter adjustment unit 125 changes at least one control parameter to mitigate the error cause indicated by the cause information.

[0089] As an example, if the parameter adjustment unit 125 indicates a positional shift of the nozzle 41, which is the most likely cause of error, it changes the position of the nozzle 41 when discharging the removal liquid. If the parameter adjustment unit 125 indicates a change in the amount of removal liquid discharged from the nozzle 41, which is the most likely cause of error, it changes the discharge volume of the removal liquid from the nozzle 41. If the parameter adjustment unit 125 indicates a positional shift of the substrate W on the rotating holding unit 20, which is the most likely cause of error, it changes the placement position of the substrate W within the coating unit U1 by the conveying arm A3.

[0090] Figure 5 This is a block diagram illustrating the hardware structure of the control unit 100. The control unit 100 is composed of one or more control computers. Figure 5 As shown, the control unit 100 includes a circuit 190. The circuit 190 includes at least one processor 191, a memory 192, a storage device 193, an input / output port 194, an input device 195, and a display device 196. The storage device 193 may be a computer-readable storage medium, such as a hard disk. The storage device 193 stores a program for causing the control unit 100 to perform the following steps: a step of having the coating unit U1 remove the peripheral portion of the resist film formed on the surface Wa of the substrate W; a step of obtaining a removal width distribution from the inspection unit U3 indicating the relationship between the circumferential position of the substrate W and the removal width; and a step of outputting cause information indicating the cause of the removal width error based on the removal width distribution. For example, the storage device 193 stores a program for constructing the aforementioned functional blocks in the control unit 100.

[0091] The memory 192 temporarily stores programs downloaded from the storage medium of the storage device 193 and the calculation results of the processor 191. The processor 191, in cooperation with the memory 192, executes the aforementioned programs to form the aforementioned functional blocks. The input / output port 194, according to instructions from the processor 191, performs input / output of electrical signals between the transport arm A3, the coating unit U1, and the inspection unit U3. The input device 195 and the display device 196 function as the user interface of the control unit 100. The input device 195, for example, is a keyboard, which acquires user input information. The display device 196, for example, includes a liquid crystal monitor, which is used to display information to the user. The display device 196 is used, for example, to display the aforementioned reason information. The input device 195 and the display device 196 can be integrated as a so-called touch panel.

[0092] (Control Steps)

[0093] The following describes the control steps of the coating and developing apparatus 2 performed by the control unit 100 as an example of a substrate processing method. The overall steps are explained in the (Substrate Processing Apparatus) section. In addition to the steps described above, the control steps of the coating and developing apparatus 2 performed by the control unit 100 also include a film formation control step, a removal distribution acquisition step, and a cause information output step.

[0094] The film formation control step is a control step in which the control unit 100 causes the coating unit U1 to perform the formation of the resist film before baking and the removal of the peripheral portion of the resist film before baking. The removal distribution acquisition step is a step in which the control unit 100 acquires the removal distribution by having the inspection unit U3 measure the removal width at at least two locations in the circumferential direction of the substrate W. The cause information output step is a step in which the control unit 100 outputs cause information indicating the cause of the error in the removal width based on the removal distribution. Hereinafter, the film formation control step, the removal distribution acquisition step, and the cause information output step will be described in detail.

[0095] (Film formation control steps)

[0096] like Figure 6 As shown, the control unit 100 sequentially executes steps S01, S02, S03, S04, S05, S06, and S07. In step S01, based on the operation program stored in the program storage unit 114, the transport control unit 111 controls the transport arm A3 to place the substrate W into the coating unit U1. At this time, the device status acquisition unit 117 acquires information about the placement position of the substrate W by the transport arm A3. In step S02, the film formation control unit 112 causes the holding unit 21 to hold the substrate W placed into the coating unit U1 by the transport arm A3. In step S03, the film formation control unit 112 causes the holding unit 21 and the substrate W to start rotating by the rotation drive unit 22.

[0097] In step S04, based on the operation program stored in the program storage unit 114, the film formation control unit 112 controls the coating unit U1 to form a pre-baking resist film on the surface Wa of the substrate W. For example, the film formation control unit 112 controls the nozzle moving unit 34 to position the nozzle 31 at the rotation center CL of the substrate W, and controls the liquid delivery unit 33 to discharge the processing liquid from the nozzle 31 for a predetermined period. This forms a liquid film of the processing liquid on the surface Wa. Then, the film formation control unit 112 controls the liquid delivery unit 33 to stop the discharge of the processing liquid from the nozzle 31, and uses the nozzle moving unit 34 to retract the nozzle 31 from the substrate W. After the discharge of the processing liquid stops, the film formation control unit 112 controls the rotation drive unit 22 to continue the rotation of the substrate W for a predetermined period. This dries the liquid film, forming a pre-baking resist film.

[0098] In step S05, based on the operation program stored in the program storage unit 114, the peripheral removal control unit 113 controls the coating unit U1 to remove the peripheral portion of the resist film before baking. For example, the peripheral removal control unit 113 controls the nozzle moving unit 44 to position the nozzle 41 on the peripheral portion of the substrate W, and controls the liquid delivery unit 43 to ensure that the discharge of removal liquid from the nozzle 41 continues for a predetermined period. Thus, the peripheral portion of the resist film before baking is removed.

[0099] When the resist film before baking is removed, the device status acquisition unit 117 acquires information about the configuration position of the nozzle 41 as determined by the nozzle movement unit 44 and the discharge amount of the removal liquid from the nozzle 41 (e.g., the detection value of the flow sensor 45). Then, the peripheral removal control unit 113 controls the liquid delivery unit 43 to stop the discharge of the removal liquid from the nozzle 41, and the nozzle movement unit 44 retracts the nozzle 41 from the substrate W.

[0100] In step S06, the peripheral removal control unit 113 stops the rotation of the holding part 21 and the substrate W by rotating the drive unit 22. In step S07, the peripheral removal control unit 113 causes the holding part 21 to release the substrate W, and the transport control unit 111 controls the transport arm A3 to deliver the substrate W out of the coating unit U1. As described above, the film formation control step ends.

[0101] (Steps for obtaining the distribution are removed)

[0102] like Figure 7 As shown, the control unit 100 first executes steps S11, S12, S13, S14, S15, S16, and S17. In step S11, based on the operation program stored in the program storage unit 114, the transport control unit 111 controls the transport arm A3 to place the substrate W into the inspection unit U3. In step S12, the distribution acquisition unit 115 causes the holding unit 51 to hold the substrate W placed into the inspection unit U3 by the transport arm A3. In step S13, the distribution acquisition unit 115 causes the holding unit 51 and the substrate W to start rotating by the rotation drive unit 52.

[0103] In step S14, the distribution acquisition unit 115 waits for the position index detection unit 53 to detect the position index (e.g., a notch). In step S15, the distribution acquisition unit 115 waits for the rotation angle after notch detection to reach a predetermined measurement angle. In step S16, the distribution acquisition unit 115 causes the imaging unit 57 to capture images of the periphery of the substrate W, calculates the removal width based on the captured image, and stores it in association with the current measurement angle. In step S17, the distribution acquisition unit 115 confirms whether the removal width acquisition has been completed across the entire circumference of the substrate W. For example, the distribution acquisition unit 115 confirms whether the removal width acquisition is complete for all predetermined measurement areas along the periphery of the substrate W.

[0104] If, in step S17, it is determined that there is residual material at the periphery of the substrate W where the acquisition of the removal width was not completed, the control unit 100 returns the process to step S15. Thereafter, the removal width corresponding to the predetermined measurement angle is repeatedly acquired until the acquisition of the removal width is completed throughout the entire circumference.

[0105] If, in step S17, it is determined that the removal width has been acquired covering the entire circumference of the substrate W, the control unit 100 executes steps S18 and S19. In step S18, the distribution acquisition unit 115 stops the rotation of the holding unit 51 and the substrate W by rotating the drive unit 52. In step S19, the distribution acquisition unit 115 releases the substrate W from the holding unit 51, and the transport control unit 111 controls the transport arm A3 to send the substrate W out of the inspection unit U3. As described above, the removal distribution acquisition step ends.

[0106] (Steps for outputting cause information)

[0107] like Figure 8 As shown, the control unit 100 first executes steps S21, S22, S23, S24, and S25. In step S21, the feature quantity calculation unit 116 waits for the completion of the removal distribution acquisition performed by the distribution acquisition unit 115. In step S22, the feature quantity calculation unit 116 calculates the aforementioned multiple types of feature quantities based on the removal width distribution. In step S23, the record generation unit 118 generates a record containing the calculation results of the feature quantities and the state of the coating unit U1 corresponding to the feature quantity, and saves it in the data storage unit 119. The record generation unit 118 acquires information indicating the state of the coating unit U1 corresponding to the feature quantity from the device state acquisition unit 117.

[0108] In step S24, the evaluation unit 121 evaluates the removal width based on the removal width distribution. For example, the evaluation unit 121 evaluates the maximum and minimum values ​​of the removal width in the removal width distribution. In step S25, the contribution evaluation unit 122 confirms whether the evaluation result of the removal width by the evaluation unit 121 is outside the specified range. For example, the contribution evaluation unit 122 determines that the evaluation result of the removal width is outside the specified range if the maximum value of the removal width exceeds the upper limit of the specified range, and also determines that the evaluation result of the removal width is outside the specified range if the minimum value of the removal width is below the lower limit of the specified range.

[0109] If, in step S25, the evaluation result for removing the width is determined to be outside the specified range, the control unit 100 executes steps S26, S27, and S28. In step S26, the contribution evaluation unit 122 evaluates the contribution of multiple types of feature quantities to the error based on the calculation results of these feature quantities. In step S27, the cause inference unit 124 derives the error cause associated with the feature quantity with the largest contribution based on the candidate cause storage unit 123. In step S28, the cause inference unit 124 confirms whether the feature quantity with the largest contribution is the aforementioned composite feature quantity.

[0110] If, in step S28, it is determined that the feature quantity with the largest contribution is a composite feature quantity, the control unit 100 executes steps S31, S32, and S33. In step S31, if the feature quantity with the largest contribution is a composite feature quantity, the cause inference unit 124 evaluates the correlation level between each of the multiple types of error causes and the composite feature quantity based on the records stored in the data storage unit 119. In step S32, the cause inference unit 124 selects the error cause with the largest correlation level among the multiple error causes associated with the composite feature quantity. In step S33, the cause inference unit 124 outputs cause information representing the error cause selected in step S32.

[0111] If, in step S28, it is determined that the feature quantity with the largest contribution is not a composite feature quantity, the control unit 100 executes step S33 instead of steps S31 and S32. In this case, the cause inference unit 124 outputs cause information indicating the cause of the error derived in step S27.

[0112] Next, the control unit 100 executes step S34. In step S34, the parameter adjustment unit 125 adjusts at least one control parameter in the action program stored in the program storage unit 114 based on the cause information.

[0113] If, in step S25, the evaluation result of the width removal is determined to be within the specified range, the contribution evaluation unit 122 omits the calculation of the contribution, the cause inference unit 124 omits the output of cause information, and the parameter adjustment unit 125 omits the adjustment of the control parameters. As described above, the cause information output step ends.

[0114] (Effects of this implementation method)

[0115] As described above, the coating and developing apparatus 2 (substrate processing apparatus) includes: a coating unit U1 (peripheral removal unit) that removes the peripheral portion of the coating formed on the surface Wa of the substrate W; a distribution acquisition unit 115 that acquires a removal width distribution indicating the relationship between the circumferential position of the substrate W and the width of the portion of the substrate W where the coating has been removed; and a cause inference unit 124 that outputs cause information indicating the cause of the width error based on the removal width distribution.

[0116] Removal width errors occur due to various reasons; however, determining the cause of the error solely based on error evaluation results is time-consuming. Furthermore, the removal width distribution, which represents the relationship between the circumferential position of the substrate W and the removal width, tends to exhibit different characteristics depending on the cause of the error. Therefore, reliable cause information can be output based on the removal width distribution. Based on this reliable cause information, the cause of the error can be quickly determined for adjustment. Thus, the coating and developing apparatus 2 enables rapid adjustment of the removal width.

[0117] The coating and developing apparatus 2 also includes an evaluation unit 121 that evaluates width based on the removal width distribution, and a cause inference unit 124 that can output cause information when the width evaluation result is outside a specified range. In this case, by only outputting cause information when the error evaluation result exceeds a specified level, the information processing load in the coating and developing apparatus 2 can be reduced.

[0118] The coating and developing apparatus 2 also includes a feature quantity calculation unit 116 that calculates multiple types of feature quantities associated with at least one cause of error based on the removal width distribution. The cause inference unit 124 can output cause information based on the calculation results of the multiple types of feature quantities. In this case, it is easier to output cause information.

[0119] Multiple types of feature quantities can include evaluation values ​​for width, deviation of the coating periphery from the substrate periphery, roundness of the coating periphery, and roughness of the coating periphery. In this case, more useful causal information can be output.

[0120] The coating unit U1 includes: a rotating holding part 20 that holds and rotates a substrate W; and a nozzle 41 that discharges a removal liquid for removing the coating to the periphery of the substrate W held and rotated by the rotating holding part 20. The evaluation value of the width is associated at least with the positional offset of the nozzle 41 and the variation in the discharge amount of the removal liquid from the nozzle 41; the evaluation value of the deviation is associated at least with the positional offset of the substrate W on the rotating holding part 20; the evaluation value of the roundness is associated at least with the deformation of the substrate W and the deformation of the rotating holding part 20; and the evaluation value of the roughness is associated at least with the liquid splashing of the removal liquid and the variation in the discharge amount of the removal liquid from the nozzle 41. In this case, more useful causal information can be output.

[0121] The coating and developing apparatus 2 also includes a contribution evaluation unit 122 that evaluates the contribution of multiple types of feature quantities to the error based on calculation results of multiple types of feature quantities. The cause inference unit 124 can output cause information based on the contribution of multiple types of feature quantities to the error. In this case, more reliable cause information can be easily output.

[0122] The cause inference unit 124 can output cause information based on at least one error cause among multiple types of error causes that is associated with at least the feature quantity that contributes the most. In this case, cause information that is easier to understand can be output.

[0123] The multiple types of feature quantities include composite feature quantities associated with multiple types of error causes. When the feature quantity with the largest contribution is a composite feature quantity, the cause inference unit 124 can output cause information based on the multiple types of error causes associated with the composite feature quantity and the state of the coating unit U1. In this case, more reliable cause information can be output.

[0124] The embodiments have been described above. However, the present invention is not limited to the embodiments described above, and various modifications can be made without departing from its spirit.

Claims

1. A substrate processing apparatus, characterized in that, include: The peripheral removal section removes the peripheral portion of the coating formed on the surface of the substrate; The distribution acquisition unit acquires a removal width distribution that represents the relationship between the circumferential position of the substrate and the width of the portion of the substrate from which the coating has been removed. and The feature calculation unit calculates multiple types of feature quantities associated with the cause of error in at least one of the widths based on the removed width distribution; The cause inference unit, based on the calculation results of the multiple types of feature quantities, outputs cause information indicating the cause of the error. The plurality of characteristic quantities include an evaluation value for the width, an evaluation value for the deviation of the periphery of the coating from the periphery of the substrate, an evaluation value for the roundness of the periphery of the coating, and an evaluation value for the roughness of the periphery of the coating.

2. The substrate processing apparatus as described in claim 1, characterized in that: The cause inference unit outputs the cause information when the evaluation value of the width is outside the specified range.

3. The substrate processing apparatus as described in claim 1 or 2, characterized in that: The peripheral removal section has: A rotation holding part capable of holding and rotating the substrate; and A nozzle discharges a removal liquid for removing the coating to the periphery of the substrate, which is held and rotated by the rotating holding part. The evaluation value of the width is related at least to the positional offset of the nozzle and the change in the discharge rate of the removal fluid from the nozzle. The evaluation value of the deviation is at least related to the positional offset of the substrate on the rotating holding part. The evaluation value for roundness is at least related to the deformation of the substrate and the deformation of the rotating holding part. The roughness evaluation value is at least related to the variation in liquid splashing of the removal fluid and the amount of removal fluid discharged from the nozzle.

4. The substrate processing apparatus as described in claim 1 or 2, characterized in that: It also includes a contribution evaluation unit that evaluates the contribution of the multiple types of feature quantities to the error based on the calculation results of the multiple types of feature quantities. The cause inference unit outputs the cause information based on the contribution of the multiple types of feature quantities to the error.

5. The substrate processing apparatus as described in claim 4, characterized in that: The cause inference unit outputs the cause information based on at least one cause of the error that is associated with the feature quantity that has the greatest contribution among the multiple types of causes of the error.

6. The substrate processing apparatus as described in claim 1 or 2, characterized in that: The multiple types of feature quantities include composite feature quantities that are associated with the causes of the multiple types of errors. When the feature quantity with the largest contribution is the composite feature quantity, the cause inference unit outputs the cause information based on the causes of multiple types of errors associated with the composite feature quantity and the state of the perimeter removal unit.

7. A method for inferring substrate processing, characterized in that, include: In the substrate processing of a substrate processing apparatus that removes the peripheral portion of a coating formed on the surface of a substrate, a removal width distribution representing the relationship between the circumferential position of the substrate and the width of the portion of the substrate from which the coating has been removed is obtained in the distribution acquisition step. The feature quantity calculation step calculates multiple types of feature quantities associated with the cause of error in at least one of the widths based on the removed width distribution; and The cause inference step outputs cause information representing the cause of the error based on the calculation results of the multiple types of feature quantities. The plurality of characteristic quantities include an evaluation value for the width, an evaluation value for the deviation of the periphery of the coating from the periphery of the substrate, an evaluation value for the roundness of the periphery of the coating, and an evaluation value for the roughness of the periphery of the coating.

8. The inference method for substrate processing as described in claim 7, characterized in that: In the cause inference step, the cause information is output when the evaluation value of the width is outside the specified range.

9. The inference method for substrate processing as described in claim 7 or 8, characterized in that: The substrate processing has the following characteristics: Rotation process that holds the substrate and rotates the substrate; and A removal process for removing the coating is performed by discharging a removal solution to the periphery of the substrate, which is held and rotated. The evaluation value of the width is at least related to the offset of the discharge position of the removed liquid and the change in the discharge amount of the removed liquid during the discharge process. The evaluation value of the deviation is at least related to the positional offset of the substrate during rotational holding. The evaluation value for roundness is at least related to the deformation of the substrate and the deformation during rotational retention. The roughness evaluation value is at least related to the variation in liquid splashing of the removal liquid and the amount of removal liquid discharged during the discharge process.

10. The inference method for substrate processing as described in claim 7 or 8, characterized in that: It also includes a contribution evaluation step that assesses the contribution of the multiple types of feature quantities to the error based on the calculation results of the multiple types of feature quantities. In the cause inference step, the cause information is output based on the contribution of the multiple types of feature quantities to the error.

11. The inference method for substrate processing as described in claim 10, characterized in that: In the cause inference step, the cause information is output based on at least one cause of the error that is associated with the feature quantity that has the greatest contribution among the multiple types of causes of the error.

12. The inference method for substrate processing as described in claim 7 or 8, characterized in that: The multiple types of feature quantities include composite feature quantities that are associated with the causes of the multiple types of errors. In the cause inference step, when the feature quantity with the largest contribution is the composite feature quantity, the cause information is output based on the causes of the errors of multiple types associated with the composite feature quantity and the state of the substrate processing.

13. A computer storage medium, characterized in that: The device stores a program for performing the inference method for substrate processing as described in claim 7.

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