Substrate processing control method, substrate processing apparatus, and storage medium

Abstract

The present invention provides a substrate processing control method, a substrate processing apparatus, and a storage medium that appropriately control various parameters according to a state of substrate processing. A substrate processing control method in a substrate processing apparatus having a first element including a plurality of first level units and a second element including a plurality of second level units includes: an acquisition step of acquiring, for each substrate, a data set including information that specifies a first level unit on which a first processing was performed, information that specifies a second level unit on which a second processing was performed, and information on a characteristic quantity regarding a characteristic of the substrate; a calculation step of calculating, based on the data set, information including an expected value of the characteristic quantity, a level unit deviation of the first level unit with respect to the expected value, and a level unit deviation of the second level unit with respect to the expected value; and a correction step of correcting a first parameter of the first level unit or a second parameter of the second level unit based on the information calculated in the calculation step.

Description

Technical Field

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

[0002] Patent Document 1 discloses a technique for measuring the size of a resist pattern after it has been formed on a substrate, and adjusting the heat treatment temperature based on the result. Furthermore, Patent Document 1 also describes a technique for measuring the size of the heat-treated resist pattern at the adjusted processing temperature, and adjusting the exposure processing conditions based on the inspection results.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-267144 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] This invention provides a technique for appropriately controlling various parameters based on the state of substrate processing.

[0008] Technical solutions for solving technical problems

[0009] One aspect of the present invention is a substrate processing control method within a substrate processing apparatus, the substrate processing apparatus comprising: a first element comprising a plurality of first leveling units for performing a first processing on a substrate based on a first parameter; and a second element comprising a plurality of second leveling units for performing a second processing on a substrate based on a second parameter. The substrate processing control method comprises: an acquisition step, which acquires a dataset for each of the plurality of substrates that has undergone the first processing in the first leveling unit and then the second processing in the second leveling unit, the dataset comprising: information determining the first leveling unit that has undergone the first processing; information determining the second leveling unit that has undergone the second processing; and information regarding a characteristic quantity of the substrate; a calculation step, which calculates, based on the dataset corresponding to each of the plurality of substrates, information including an expected value of the characteristic quantity, a leveling unit deviation of the first leveling unit relative to the expected value, and a leveling unit deviation of the second leveling unit relative to the expected value; and a correction step, which corrects the first parameter in the first leveling unit or the second parameter in the second leveling unit based on the information calculated in the calculation step.

[0010] Invention Effects

[0011] According to the present invention, a technique is provided for appropriately controlling various parameters based on the state of substrate processing. Attached Figure Description

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

[0013] Figure 2 This is a schematic diagram illustrating an example of a coating and developing apparatus.

[0014] Figure 3 This is a schematic diagram representing an example of an inspection unit.

[0015] Figure 4 This is a block diagram representing an example of the functional structure of a control device.

[0016] Figure 5 This is a block diagram representing an example of the hardware structure of a control device.

[0017] Figure 6 This is a flowchart illustrating an example of control performed by a control device.

[0018] Figure 7 (a) and Figure 7 (b) is a figure used to illustrate an example of film thickness correction.

[0019] Figure 8 This is a flowchart illustrating an example of a method for calculating unit deviations performed by a control device.

[0020] Figure 9 (a) and Figure 9 (b) is a graph showing an example of the calculation results of the inspection results and unit deviations.

[0021] Figure 10 (a) and Figure 10 (b) is a graph showing an example of the calculation results of the inspection results and unit deviations.

[0022] Figure 11 This is a graph representing an example of the calculation results for unit deviation.

[0023] Figure 12 This is a graph representing an example of the calculation results for unit deviation.

[0024] Explanation of reference numerals in the attached figures

[0025] 1…Substrate processing system; 2…Coating and developing device; 3…Exposure device; 11-14…Processing module; 100…Control device; 101…Inspection result holding unit; 102…Correction value calculation unit; 103…Regression coefficient calculation unit; 104…Parameter correction value calculation unit; 106…Scheme holding unit; 107…Unit control unit; U1…Coating unit; U2…Heat treatment unit; U3…Inspection unit. Detailed Implementation

[0026] The following describes various illustrative implementation methods.

[0027] In one exemplary embodiment, the substrate processing control method is a substrate processing control method within a substrate processing apparatus, the substrate processing apparatus comprising: a first element comprising a plurality of first leveling units that perform a first processing on a substrate based on a first parameter; and a second element comprising a plurality of second leveling units that perform a second processing on a substrate based on a second parameter. The substrate processing control method comprises: an acquisition step, which acquires a dataset for each of the plurality of substrates that has undergone the first processing in the first leveling unit and then the second processing in the second leveling unit, the dataset comprising: information determining the first leveling unit that has undergone the first processing; information determining the second leveling unit that has undergone the second processing; and information regarding a characteristic quantity of the substrate; a calculation step, which calculates, based on the dataset corresponding to each of the plurality of substrates, information including an expected value of the characteristic quantity, a leveling unit deviation of the first leveling unit relative to the expected value, and a leveling unit deviation of the second leveling unit relative to the expected value; and a correction step, which corrects the first parameter in the first leveling unit or the second parameter in the second leveling unit based on the information calculated in the calculation step.

[0028] In the aforementioned substrate processing control method, a dataset can be obtained containing information about a first leveling unit that has undergone first processing, information about a second leveling unit that has undergone second processing, and information about feature quantities related to the substrate's characteristics. Then, based on this dataset, in the calculation step, information including expected values ​​of the feature quantities, leveling unit deviations of the first leveling unit relative to the expected values, and leveling unit deviations of the second leveling unit relative to the expected values ​​can be calculated. Furthermore, based on the calculated information, a first parameter in the first leveling unit or a second parameter in the second leveling unit can be corrected. By adopting this configuration, parameter correction can be performed based on the expected values ​​and leveling deviations of the feature quantities calculated for the first and second leveling units. Therefore, even for substrates that have undergone processing in multiple leveling units, such as multiple types of processing units, appropriate corrections relative to the target value can be performed for each unit using a dataset containing the substrate's feature quantities.

[0029] Alternatively, in the above calculation steps, based on the dataset corresponding to each of the plurality of substrates, information including the leveling unit deviation of the first leveling unit relative to the expected value and the leveling unit deviation of the second leveling unit relative to the expected value is calculated, so as to minimize the norm other than the expected value of the feature quantity based on the dataset.

[0030] In the above configuration, when calculating the first leveling unit deviation in the first leveling unit and the second leveling unit deviation in the second leveling unit, the leveling unit deviation is calculated to minimize the norm other than the expected value of the feature quantity. Therefore, even when only a dataset is available where the range of unit deviations for each unit cannot be calculated using existing methods such as least squares, the first and second leveling unit deviations can still be calculated. Thus, appropriate corrections can be made for each unit relative to the expected value of the feature quantity.

[0031] Alternatively, in the above calculation steps, if the norm minimization priority corresponding to the order in which the processing of reducing its correction value is prioritized is predetermined for the first element and the second element, based on the above dataset, the unit deviation is calculated sequentially from the element with the high norm minimization priority, so as to minimize the norm other than the expected value of the average value of the above feature quantity.

[0032] By pre-determining the norm minimization priority corresponding to the order in which processing to reduce correction values ​​is prioritized, cell deviations are calculated sequentially from the elements with the highest norm minimization priority to minimize the norm. This configuration prevents corrections to elements with high norm minimization priority from incorporating cell deviations from other elements. Therefore, correction values ​​can be reduced for elements with high norm minimization priority.

[0033] In another exemplary embodiment, the substrate processing apparatus includes: a plurality of first processing units that perform first processing on a substrate based on first parameters; a plurality of second processing units that perform second processing on the substrate based on second parameters; a feature information acquisition unit that acquires feature information of the substrate after the first processing in any of the plurality of first processing units and the second processing in any of the plurality of second processing units; and a control unit that controls the plurality of first processing units and the plurality of second processing units, the control unit controlling the plurality of first processing units and the plurality of second processing units after the first processing in any of the plurality of first processing units and the second processing in any of the plurality of second processing units. Each substrate acquires a dataset from the feature quantity information acquisition unit, wherein the dataset includes: information determining the first processing unit that has undergone the first processing; information determining the second processing unit that has undergone the second processing; and feature quantity information regarding the characteristics of the substrate. Based on the dataset corresponding to each of the plurality of substrates, the control unit calculates information including the expected value of the feature quantity, the unit deviation of the first processing unit relative to the expected value, and the unit deviation of the second processing unit relative to the expected value. Based on the calculated information, the control unit corrects the first parameter in the first processing unit or the second parameter in the second processing unit.

[0034] In another exemplary embodiment, the storage medium stores a program for enabling the device to implement the substrate processing control method described above.

[0035] Hereinafter, various exemplary embodiments will be described with reference to the accompanying drawings. In the description, the same reference numerals are used to label the same elements or elements having the same function, and repeated descriptions are omitted.

[0036] [Substrate Processing System]

[0037] 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. The substrate to be processed is, for example, a semiconductor wafer W.

[0038] The substrate processing system 1 includes a coating and developing apparatus 2 and an exposure apparatus 3. The exposure apparatus 3 performs exposure processing on the resist film (photosensitive coating) formed on the wafer W (substrate). Specifically, the exposure apparatus 3 irradiates energy lines onto the exposed portion of the resist film using methods such as immersion exposure. Before exposure processing by the exposure apparatus 3, the coating and developing apparatus 2 processes the surface of the wafer W (substrate) to form a resist film, and after exposure processing, it performs development processing on the resist film.

[0039] [Substrate Processing Device]

[0040] The structure of the coating and developing apparatus 2 will be described below as an example of a substrate processing apparatus. Figure 1 and Figure 2 As shown, the coating and developing apparatus 2 includes a carrier block 4, a processing block 5, an interface block 6, and a control unit 100.

[0041] The carrier block 4 introduces and removes wafers W into and from the coating and developing apparatus 2. For example, the carrier block 4 can support multiple carriers C (receiving sections) for wafers W and includes a transport device A1 with a transfer arm. The carriers C, for example, hold multiple circular wafers W. The transport device A1 removes wafers W from the carriers C and delivers them to the processing block 5, then retrieves the wafers W from the processing block 5 and returns them to the carriers C. The processing block 5 includes multiple processing modules 11, 12, 13, and 14.

[0042] The processing module 11 includes multiple coating units U1, multiple heat treatment units U2, multiple inspection units U3, and a transport device A3 for transporting the wafer W to these units. The processing module 11 forms a lower layer film on the surface of the wafer W using the coating units U1 and the heat treatment units U2. For example, the coating unit U1 of the processing module 11 applies a processing solution for forming the lower layer film onto the wafer W while rotating the wafer W at a predetermined speed. The heat treatment unit U2 of the processing module 11 performs various heat treatments accompanying the formation of the lower layer film. The heat treatment unit U2, for example, includes a hot plate and a cooling plate. The hot plate heats the wafer W to a predetermined heating temperature, and the cooling plate cools the heated wafer W to achieve the heat treatment. The inspection unit U3 performs processing to inspect the surface condition of the wafer W, acquiring information such as information related to the film thickness as information indicating the surface condition of the wafer W.

[0043] Processing module 12 includes multiple coating units U1, multiple heat treatment units U2, multiple inspection units U3, and a transport device A3 for transporting wafer W to the aforementioned units. Processing module 12 forms a resist film on a lower layer film using coating units U1 and heat treatment units U2. Processing module 12 is sometimes referred to as a COT module. Furthermore, the coating unit U1 of the processing module is sometimes referred to as a COT unit. The coating unit U1 of processing module 12 forms a coating film on the surface of wafer W by applying a processing liquid for resist film formation onto the lower layer film. The heat treatment unit U2 of processing module 12 performs various heat treatments accompanying the formation of the resist film. The heat treatment unit U2 of processing module 12 performs heat treatment (PAB: Pre-Applied Bake) on the wafer W with the coating film formed at a specified heating temperature to form the resist film. The inspection unit U3 performs processing to inspect the surface condition of wafer W, obtaining information such as film thickness as information indicating the surface condition of wafer W.

[0044] The processing module 13 includes multiple coating units U1, multiple heat treatment units U2, multiple inspection units U3, and a transport device A3 for transporting the wafer W to these units. The processing module 13 forms an upper layer film on a resist film using the coating units U1 and the heat treatment units U2. For example, the coating unit U1 of the processing module 13 applies a liquid for forming the upper layer film onto the resist film while rotating the wafer W at a predetermined rotational speed. The heat treatment units U2 of the processing module 13 perform various heat treatments accompanying the formation of the upper layer film. The inspection units U3 perform processing to inspect the surface condition of the wafer W, obtaining information such as film thickness as information indicating the surface condition of the wafer W.

[0045] Processing module 14 includes multiple coating units U1, multiple heat treatment units U2, and a transport device A3 for transporting wafers W to the aforementioned units. Processing module 14 uses the coating units U1 and heat treatment units U2 to develop the exposed resist film R. For example, the coating unit U1 of processing module 14 rotates the wafer W at a predetermined speed while applying developer to the surface of the exposed wafer W, followed by rinsing with rinsing solution, thereby developing the resist film R. The heat treatment unit U2 of processing module 14 performs various heat treatments accompanying the development process. Specific examples of heat treatments include heat treatment before development (PEB: Post Exposure Bake) and heat treatment after development (PB: Post Bake).

[0046] 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 chambers arranged in the vertical direction. A conveying device A7, including a lifting arm, is provided near the shelf unit U10. The conveying device A7 causes the wafer W to move up and down between the small chambers of the shelf unit U10.

[0047] A shelf unit U11 is provided on the interface block 6 side within processing block 5. The shelf unit U11 is divided into multiple small compartments arranged in the vertical direction.

[0048] Interface block 6 facilitates the transfer of the substrate W between itself and exposure apparatus 3. For example, interface block 6 may include a built-in transport device A8 with a transfer arm, which is connected to exposure apparatus 3. Transport device A8 delivers the wafer W, which is disposed in shelf unit U11, to exposure apparatus 3, retrieves the wafer W from exposure apparatus 3, and returns it to shelf unit U11.

[0049] [Inspection Unit]

[0050] The inspection unit U3 included in the processing modules 11-13 will be described. The inspection unit U3 acquires information about the film thickness (lower film, resist film, or upper film) formed by the coating unit U1 and the heat treatment unit U2. In this embodiment, film thickness is information related to the characteristics of the substrate and is used as a characteristic quantity representing the characteristics of the substrate on which the film is formed.

[0051] like Figure 3 As shown, the inspection unit U3 includes a housing 30, a holding part 31, a linear drive part 32, an imaging part 33, and a light-projecting and reflecting part 34. The holding part 31 holds the wafer W horizontally. The linear drive part 32 uses an electric motor or similar power source to move the holding part 31 along a horizontal, linear path. The imaging part 33 has a camera 35, such as a CCD camera. The camera 35 is positioned at one end of the inspection unit U3 in the direction of movement of the holding part 31, facing the other end in that direction. The light-projecting and reflecting part 34 projects light within the imaging range, guiding the reflected light from that range to the camera 35. For example, the light-projecting and reflecting part 34 has a semi-reflecting mirror 36 and a light source 37. The semi-reflecting mirror 36 is positioned higher than the holding part 31, in the middle of the movement range of the linear drive part 32, reflecting light from below to the camera 35. The light source 37 is positioned on the semi-reflecting mirror 36, illuminating light downwards through the semi-reflecting mirror 36.

[0052] The inspection unit U3 operates as follows to acquire image data of the surface of the wafer W. First, the linear drive unit 32 moves the imaging unit 33. As a result, the wafer W passes beneath the semi-reflective mirror 36. During this passage, reflected light from various parts of the wafer W's surface is sequentially sent to the camera 35. The camera 35 images the reflected light from each part of the wafer W's surface, acquiring image data of the wafer W's surface. When the thickness of the film formed on the wafer W's surface changes, for example, the color of the wafer W's surface changes accordingly with the film thickness, the image data of the wafer W's surface captured by the camera 35 changes. That is, acquiring image data of the wafer W's surface is equivalent to acquiring information related to the film thickness formed on the surface of the wafer W. Furthermore, the method for calculating the film thickness based on the image data is not particularly limited.

[0053] Image data acquired by camera 35 is sent to control device 100. In control device 100, the film thickness of the film on the surface of wafer W can be inferred based on the image data, and the inference result is stored in control device 100 as an inspection result.

[0054] [Control Device]

[0055] An example of the control device 100 will be described in detail. The control device 100 controls the various elements included in the coating and developing apparatus 2. The control device 100 is configured to perform a process that includes the steps of forming the aforementioned films on the surface of the wafer W and performing a developing process. Furthermore, the control device 100 is configured to perform adjustments to parameters related to the process based on the results of the performed process. Details of the aforementioned process will be described later.

[0056] like Figure 4 As shown, the control device 100, in terms of its functional structure, includes a check result holding unit 101, a correction value calculation unit 102, a scheme holding unit 106, and a unit control unit 107. Furthermore, the correction value calculation unit 102 includes a regression coefficient calculation unit 103 and a parameter correction value calculation unit 104.

[0057] Based on the inspection results of the inspection unit U3, the control device 100 can change the control settings in the coating unit U1 and the heat treatment unit U2. For this information, please refer to... Figure 4 The following description will be provided as an example of the control of the processing module 12 that forms a resist film on the wafer W. The processing module 12 performs the coating process (first processing) related to the coating of the processing liquid in the coating unit U1 (first processing unit) and the heat treatment process (second processing) related to the heat treatment of the processing liquid in the heat treatment unit U2 (second processing unit) on the wafer W.

[0058] The inspection result holding unit 101 has the function of acquiring and holding the inspection results of the inspection unit U3, namely the inspection results related to the resist film on the surface of the wafer W. Furthermore, in the inspection result holding unit 101, based on the process scheme held in the scheme holding unit 106 (described later), information is acquired to determine in which unit (coating unit U1 and heat treatment unit U2) the wafer W corresponding to the inspection result was processed. The inspection result holding unit 101 acquires and holds the above information in association with the inspection result as a dataset related to a substrate. The series of information (dataset) for each substrate held by the inspection result holding unit 101 can be used for calculating the correction value in the correction value calculation unit 102.

[0059] The correction value calculation unit 102 has the function of calculating correction values ​​based on a dataset containing the inspection results held in the inspection result holding unit 101. The correction value calculation performed by the correction value calculation unit 102 is performed by the regression coefficient calculation unit 103 and the parameter correction value calculation unit 104. In the regression coefficient calculation unit 103, the expected value of the set average film thickness (characteristic quantity), the expected value of the film thickness deviation between coating units U1, and the expected value of the film thickness deviation between heat treatment units U2 are calculated by regression calculation. In addition, in the parameter correction value calculation unit 104, the correction value of the parameter of each unit is calculated based on the value calculated in the regression coefficient calculation unit 103. Details of the calculation in each unit will be described later. In the correction value calculation unit 102, the correction value corresponding to each of the multiple coating units U1 and multiple heat treatment units U2 included in the processing module 12 is calculated separately.

[0060] The process plan holding unit 106 has the function of holding the process plan of the processing module 12. In the process plan, it determines which unit (coating unit U1 and heat treatment unit U2) each wafer W will be processed in, and specifies various parameters for processing in each unit.

[0061] The unit control unit 107 has the function of controlling each unit to implement the process when the process plan held in the plan holding unit 106 uses the correction value calculated in the correction value calculation unit 102.

[0062] Below, refer to Figure 4 This explains the calculation of the correction value performed by the control device 100 and the control using the correction value. As described above, the processing module 12 includes multiple coating units U1 and multiple heat treatment units U2. Figure 4 In this diagram, the coating units U1 are designated as COT1, COT2, COT3, etc. Similarly, the heat treatment units U2 are designated as PAB1, PAB2, PAB3, etc. In the processing module 12, wafer W is delivered in the order of coating units U1, heat treatment units U2, and inspection units U3, where a predetermined treatment is performed, thereby forming a resist film on the surface of wafer W. The process plan held in the plan holding unit 106 of the control device 100 determines which of the multiple coating units U1 (COT1, COT2, etc.) and heat treatment units U2 (PAB1, PAB2, etc.) wafer W passes through. Furthermore, the specific treatment performed in each unit is also determined by the process plan.

[0063] Regarding the multiple coating units U1 and multiple heat treatment units U2 included in the processing module 12, units that can form a path for a wafer W can be integrated into sets for processing. Due to structural or functional reasons of the processing module 12, a wafer W that is fed into a specific coating unit U1 (e.g., COT1) may not be fed into all heat treatment units U2. That is, for a wafer W fed into a specific coating unit U1 (e.g., COT1), the process plan is pre-designed to feed into a portion of the specific heat treatment units U2. In other words, the combination of coating units U1 and heat treatment units U2 that a wafer W can pass through is not randomly selected from all units, but selected from a specific set. The path of the wafer W is set in this way in the process plan. As described above, the multiple coating units U1 and multiple heat treatment units U2 included in the processing module 12 can be divided into multiple sets by integrating units that process the same wafer W. Figure 4 In this context, COT1~COT4 and PAB1~PAB4 form a set G1. In this state, like COT1~COT4 or PAB1~PAB4, the same group of units contained in set G1 is called an "element". Furthermore, the two units COT1 and COT2 are respectively called "level units". That is, the first element (COT group) contains multiple first level units (coating units U1), and the second element (PAB group) contains multiple second level units (heat treatment units U2). Furthermore, in... Figure 4 In this context, it indicates the existence of two sets G2 and G3, each consisting of units different from those included in set G1. In processing module 12, a wafer W forms a resist film in coating unit U1 and heat treatment unit U2 included in any of sets G1 to G3, and is inspected in inspection unit U3.

[0064] However, when the processing module 12 has multiple coating units U1 and heat treatment units U2, and each unit performs substrate processing under the same process conditions to make the resist film the same, the film formed varies depending on the characteristics of the unit, etc.

[0065] When a resist film is formed on the surface of a wafer W, for example in a coating unit U1, the film thickness varies depending on the rotational speed of the wafer W during coating. Therefore, even when multiple coating units U1 are operated with the same parameters (rotational speed), there is a possibility that the film thickness may vary due to factors other than the unit temperature. Furthermore, in a heat treatment unit U2, the film thickness varies depending on the heating temperature of the wafer W during heat treatment. However, even when multiple heat treatment units U2 are operated with the same parameters (heating temperature), there is a possibility that the temperature of the wafer W may vary slightly between units. When there is a temperature difference between the wafer W and units, there is a possibility that the thickness of the resist film formed on the wafer W may vary. As described above, even if the process scheme for forming a resist film of a specified thickness is the same, if the characteristics of each unit differ, there is a possibility that the resist film thickness may vary due to these differences. That is, depending on which unit the wafer W is processed through, there may be a situation where the resist film thickness differs between wafers W.

[0066] However, if the film thickness deviates from the desired value during processing based on the process plan due to the characteristics of a certain unit, a correction value is calculated to correct the difference between the unit and the desired value. Then, by controlling the unit using parameters that take this correction value into account, the film thickness variation caused by the unit's characteristics can be reduced. In the unit control unit 107, the parameters of the unit determined by the process plan held by the plan holding unit 106 are corrected based on the correction value, and each unit is controlled using the corrected parameters. This configuration allows for the reflection of the correction value and control of the units.

[0067] However, not all wafers W are processed through the same unit as described above, but rather by any of the coating unit U1 and heat treatment unit U2 included in a set (any of G1 to G3). Therefore, it is possible for wafers W to travel along the same path, but for each wafer W to be processed by a different unit. Therefore, if a check result shows that the film thickness of a certain wafer W is different from the film thickness preset in the process plan, it is necessary to correct at least one of the coating unit U1 or heat treatment unit U2 that processed the wafer W.

[0068] However, determining which cell to apply what degree of correction to make the film thickness approach the target value is difficult. By comparing the film thickness of wafer W processed in other cells, the characteristics of each cell can be inferred. However, it is also necessary to consider that the film thickness of wafer W processed in other cells includes the influence of the characteristics of those other cells. In modules that perform multiple processes, such as processing module 12, it is sometimes difficult to determine which stage of the multiple processes affected the characteristics of the finished product (e.g., the thickness of the resist film).

[0069] In the case where the set G1 of processing module 12 contains multiple coating units U1 and multiple heat treatment units U2 within the same set, when a specified inspection result exists, it is possible to determine which unit exerted what kind of influence on the film thickness. That is, it is possible to determine the deviation (unit deviation) of each unit based on the specified inspection result. Here, unit deviation refers to the deviation of the film thickness change after processing by each unit from the expected value. The film thickness change of coating unit U1 is the film thickness of the coating amount of the treatment liquid, and the film thickness change of heat treatment unit U2 is the change of film thickness before and after heat treatment. Unit deviation can also be called level unit deviation. Sometimes the unit deviation of coating unit U1 is called the first level unit deviation, and the unit deviation of heat treatment unit U2 is called the second level unit deviation.

[0070] Specifically, for example, when the film thickness inspection results for all combinations of cells that wafer W can pass within the set exist, the least squares method can be used to determine which cell exerted what effect on the film thickness. That is, in the cases of COT1~COT4 and PAB1~PAB4, when the 16 results for all combinations are consistent, the cell deviation of each cell can be determined. Furthermore, as another example, when there are no combinations of all cells, if the combinations of cells that wafer W has passed are not divided into multiple smaller sets, the series of inspection results (prescribed inspection results) contained in that smaller set can be used. Here, the "smaller set" is related to each other and can also be called a subset. However, cells that wafer W did not pass (cells for which no inspection results exist) cannot be evaluated.

[0071] However, even within the same set of cells, there are instances where specific combinations of coating and heat treatment units are not executed in the processing flow of wafer W within the device. In such cases, even within the same set of cells, the combinations of units through which wafer W has passed are divided into multiple smaller sets (subsets), making it difficult to determine cell deviations. In this situation, after applying some inferences, it is necessary to calculate correction values ​​for each cell.

[0072] Furthermore, when controlling the rotation speed of the coating unit U1 or the heating temperature of the heat treatment unit U2 by applying correction values ​​to maintain the film thickness of the wafer W at a specified value, the ease of control differs between the coating unit U1 and the heat treatment unit U2. For example, controlling the rotation speed variation in the coating unit U1 is relatively easy, but sometimes controlling the heating temperature variation in the heat treatment unit U2 is more difficult than controlling the rotation speed variation. Therefore, when the correction value for each unit is calculated after applying some inference rather than being able to calculate it correctly, inference is sometimes required to reduce the amount of heating temperature correction. As described above, when performing a two-stage process (coating and heat treatment) using two different parameters to achieve a specified film thickness for the wafer W, the priority of correction is sometimes determined.

[0073] Therefore, in the control device 100, when correcting the coating unit U1 and heat treatment unit U2 within the processing module 12, a concept called a set target value (film thickness as a set target) is set. Then, in the control device 100, the average film thickness of each set is brought close to the set target value, and a correction value for reducing the unit deviation of each unit is calculated. The set target value can be the film thickness as a target value specified by the user, or it can be the average of all units contained in any of the multiple sets included in the device. Alternatively, the set target value can be the average film thickness of each set, and no correction is performed on the average film thickness of the set, but a correction value is calculated to reduce the unit deviation only. In the above correction, the correction for reducing the unit deviation is also called the intralayer average correction. Furthermore, if the set target value is different from the current average film thickness, a correction is performed to make the expected value of the average film thickness become the set target value; this correction is called target correction.

[0074] Subsequently, based on the aforementioned correction values, correction values ​​for each coating unit U1 and each heat treatment unit U2 within the processing module 12 are calculated. The regression coefficient calculation unit 103 and the parameter correction value calculation unit 104 perform the correction values ​​for each of the aforementioned stages. Details of the calculation of correction values ​​for each stage will be explained later.

[0075] The control device 100 may be composed of one or more control computers. For example, the control device 100 has... Figure 5The circuit 120 shown has one or more processors 121, memory 122, storage 123, and input / output ports 124. The memory 123 has a computer-readable storage medium, such as a hard disk. The storage medium stores a program for causing the control device 100 to perform the process flow described later. The storage medium can be a removable medium such as a non-volatile semiconductor memory, a disk, or an optical disk. The memory 122 temporarily stores the program loaded from the storage medium of the memory 123 and the calculation results of the processor 121. The processor 121 and the memory 122 cooperate to execute the program, thereby constituting the functional modules described above. The input / output ports 124, according to instructions from the processor 121, perform electrical signal input and output between the input / output ports and the components being controlled.

[0076] Furthermore, the hardware structure of the control unit 100 is not necessarily limited to functional modules composed of programs. For example, each functional module of the control unit 100 may be composed of dedicated logic circuits or ASICs (Application Specific Integrated Circuits) obtained by integrating them.

[0077] [Process Flow]

[0078] The following describes the process flow implemented in the coating and developing apparatus 2 as an example of coating and developing treatment.

[0079] In the process flow, firstly, the control device 100 controls the conveying device A1 to transport the wafer W, which is the object of the process, in the carrier C to the shelf unit U10, and controls the conveying device A7 to arrange the wafer W in the small chamber of the processing module 11.

[0080] Next, the control device 100 controls the transport device A3 to transport the wafer W from the shelf unit U10 to the coating unit U1 and the heat treatment unit U2 within the processing module 11. Furthermore, the control device 100 controls the coating unit U1 and the heat treatment unit U2 to form a lower layer film on the surface of the wafer W. Alternatively, after the lower layer film is formed, the control device 100 can control the transport device A3 to transport the wafer W to the inspection unit U3, where the inspection unit U3 inspects the surface condition of the wafer W (e.g., the thickness of the lower layer film). Afterward, the control device 100 controls the transport device A3 to return the wafer W with the lower layer film formed to the shelf unit U10, and controls the transport device A7 to place the wafer W in a chamber for the processing module 12.

[0081] Next, the control device 100 controls the transport device A3 to transport the wafer W from the shelf unit U10 to the coating unit U1 and the heat treatment unit U2 within the processing module 12. Furthermore, the control device 100 controls the coating unit U1 and the heat treatment unit U2 to form a resist film R on the lower film of the wafer W. For example, the control device 100 controls the coating unit U1 to form a resist coating by applying a processing solution for resist film formation to the lower film of the wafer W. Next, the control device 100 controls the heat treatment unit U2 to perform heat treatment on the resist coating. After the resist film R is formed, the control device 100 controls the transport device A3 to transport the wafer W to the inspection unit U3, and controls the inspection unit U3 to inspect the surface condition of the wafer W (e.g., the thickness of the resist film).

[0082] Furthermore, after obtaining the inspection results from the inspection unit U3, the control device 100 calculates the expected value of the average film thickness within the set and the unit deviations of the coating unit U1 and the heat treatment unit U2 based on the inspection results. Specifically, it calculates the unit deviations (first unit deviation, second unit deviation) of the rotation speed (first parameter) in the coating unit U1 (first processing unit) and the heating temperature (second parameter) in the heat treatment unit U2 (second processing unit). Then, the control device 100 determines a correction value for the film thickness based on the calculated unit deviations, and controls the rotation speed or heating temperature in each unit based on this value.

[0083] Subsequently, the control device 100 controls the conveying device A3 to send the wafer W back to the shelf unit U10, and controls the conveying device A7 to place the wafer W in the unit used by the processing module 13.

[0084] Next, the control device 100 controls the transport device A3 to transport the wafer W from the shelf unit U10 to the respective units within 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 wafer W. Alternatively, after the upper film is formed, the control device 100 can control the transport device A3 to transport the wafer W to the inspection unit U3, and use the inspection unit U3 to inspect the surface condition of the wafer W (e.g., the thickness of the upper film). Afterward, the control device 100 controls the transport device A3 to transport the wafer W to the shelf unit U11.

[0085] Next, the control device 100 controls the transport device A8 to deliver the wafer W from the shelf unit U11 to the exposure device 3. After that, the control device 100 controls the transport device A8 to receive the wafer W that has undergone exposure processing from the exposure device 3 and place it in the unit of the processing module 14 in the shelf unit U11.

[0086] Next, the control device 100 controls the conveying device A3 to transport the wafer W from the shelf unit U11 to the respective units within the processing module 14, and controls the coating unit U1 and the heat treatment unit U2 to perform development processing on the resist film R of the wafer W. Afterwards, the control device 100 controls the conveying device A3 to return the wafer W to the shelf unit U10, and controls the conveying devices A7 and A1 to return the wafer W to the carrier C. The process is then complete.

[0087] [Substrate Processing Control Method]

[0088] Below, refer to Figures 6-12 This describes the substrate processing control method performed by the control device 100 on the processing module 12. The substrate processing control method includes: the calculation process of the rotation speed (first parameter) of the coating unit U1 (first processing unit) and the correction value of the heating temperature (second parameter) of the heat treatment unit U2 (second processing unit); and the control process of each unit.

[0089] like Figure 6 As shown, firstly, the control device 100 executes step S01 (acquisition step). In step S01, the inspection result (film thickness inspection result) of the wafer W is acquired from the inspection unit U3 and stored in the inspection result holding unit 101. At this time, in the inspection result holding unit 101, information on the units (coating unit U1 and heat treatment unit U2) that have processed the wafer W is acquired is acquired from the scheme holding unit 106. Thus, a series of data sets are acquired in the control device 100. In addition, the information on the units (coating unit U1 and heat treatment unit U2) that have processed the wafer W can also be acquired from the inspection unit U3.

[0090] Next, the control device 100 executes step S02 (calculation step). In step S02, in the regression coefficient calculation unit 103 of the correction value calculation unit 102, a model of film thickness variation is created based on the inspection results held in the inspection result holding unit 101. Specifically, the regression coefficient calculation unit 103 creates a model of film thickness variation corresponding to changes in the parameter settings of each unit under the condition of controlling the film thickness of each process in the coating unit U1 and heat treatment unit U2 in the determined set. Then, based on this model, a function (objective function) is set to infer the expected value of the average film thickness in the determined set, the expected value of the unit deviation of the coating unit U1, and the expected value of the unit deviation of the heat treatment unit U2. After that, the optimal solution of the expected value of the average film thickness, the unit deviation of the coating unit U1, and the unit deviation of the heat treatment unit U2 is obtained so that the expected value of the average film thickness is close to the above-mentioned set target value, and the unit deviation of the coating unit U1 and the heat treatment unit U2 is close to 0. The expected value of the average film thickness, the optimal solution of the unit deviation of coating unit U1 and the unit deviation of heat treatment unit U2 are equivalent to the regression coefficients.

[0091] The expected value of the average film thickness, the optimal solutions for the element deviations of coating unit U1 and heat treatment unit U2 can be obtained by solving a least squares problem with equality constraints. This least squares problem with equality constraints is model-based, which presupposes control over the film thickness in a set containing multiple coating units U1 and multiple heat treatment units U2. However, sometimes the solution to the aforementioned least squares problem with equality constraints is not unique due to different conditions or insufficient order. Therefore, in addition to the expected value of the average film thickness, the constraint of minimizing the norms of the element deviations of coating unit U1 and heat treatment unit U2 is added, and this is expressed as a multi-objective optimization problem. Thus, by solving the aforementioned multi-objective optimization problem, regression coefficients can be calculated. Furthermore, it is also possible that, among the aforementioned constraints, the priority of minimizing the norms of the element deviations of coating unit U1 and heat treatment unit U2 (norm minimization priority) is higher than the priority of minimizing the norm of the average film thickness.

[0092] After solving the aforementioned multi-objective optimization problem and obtaining the optimal solutions for the expected value of the average film thickness, the unit deviation of coating unit U1, and the unit deviation of heat treatment unit U2, the control device 100 executes step S03 (correction step). In step S03, based on the aforementioned optimal solution, correction values ​​for the parameters corresponding to the optimal solution are obtained. The calculation of the parameter correction values ​​is performed by the parameter correction value calculation unit 104. By executing step S03, the correction value of the film thickness in each unit is determined. Therefore, the correction value of the parameters corresponding to the correction value of the film thickness is calculated. The calculation of the correction value of the parameters of each unit can be based on the relationship between the film thickness and the parameters of each unit that the control device 100 has held in advance. That is, the extent to which the film thickness changes when the parameters (norms) of each unit are changed is obtained in advance, and the magnitude of the film thickness that is to be changed by correction is obtained based on the unit deviation, thereby the correction value of the parameters can be obtained based on the pre-obtained relationship.

[0093] Next, the control device 100 executes step S04 (correction step). In step S04, the unit control unit 107 controls each unit (coating unit U1 or heat treatment unit U2) based on the process plan held in the plan holding unit 106 and the correction value calculated by the correction value calculation unit 102. By using the correction value calculated by the correction value calculation unit 102 on the parameters of each unit included in the process plan, the corrected parameters can be calculated. The unit control unit 107 controls each unit based on the corrected parameters. Thus, the process processing in each unit is performed while reflecting the correction value.

[0094] Regarding the series of steps described above, see the specific example below. Figure 7 (a) will be explained. In Figure 7 In (a), three sets G10 to G30 are shown. Set G10 consists of COT11, COT12, and PAB11 to PAB13. Set G20 consists of COT21, COT22, and PAB21 to PAB23. Set G30 consists of COT31, COT32, and PAB31 to PAB33. Figure 7 In (a), the cell thickness deviations for each cell within each set are shown. Additionally, the value R1, indicated by dashed lines for each cell in set G10, represents the average film thickness of the wafer W processed within set G10. Figure 7 In (a), the case where the average film thickness of the wafer W of the G10 assembly is 90.05 nm is shown.

[0095] The film thickness of COT11 is 89.73 nm. This means that by processing wafer W in COT11, the heat-treated resist film thickness decreased by 0.32 nm (-0.32 nm) relative to the target value of 90.05 μm, thus COT11 affected the film thickness variation. Furthermore, the film thickness of PAB11 is 90.13 nm. This means that by processing wafer W in PAB11, the heat-treated resist film thickness increased by 0.08 nm (+0.08 nm) relative to the target value of 90.05 nm, thus PAB11 affected the film thickness variation. As described above, it is known that before correction, the process treatment in each cell affected the film thickness variation of the heat-treated resist film. In the case of COT11, the cell thickness deviation is -0.32 nm, and in the case of PAB11, the cell thickness deviation is +0.08 nm. Therefore, the wafer W that passed COT11 and PAB11 is affected by the film thickness variation corresponding to the cell deviation in the two cells. The film thickness varies relative to the target value (the average film thickness of wafer W) by -0.32nm + 0.08nm = -0.24nm.

[0096] As described above, in the correction value calculation unit 102, a set target value is set for each set based on the results held in the inspection result holding unit 101. Then, in the correction value calculation unit 102, the unit deviation (first unit deviation, second unit deviation) for the film thickness variation of the process processing performed in each unit is calculated based on the difference from the set target value. Furthermore, the set target value can also be set to a value different from the average film thickness of the wafer W.

[0097] If the cell deviation for each cell group with respect to film thickness can be calculated, then the correction value can be based on that cell deviation. That is, in the case of COT11, the cell deviation relative to film thickness variation is -0.32 nm; therefore, it is only necessary to calculate the correction value for the parameters of the process used to achieve a film thickness of +0.32 nm. Furthermore, in the case of PAB11, the cell deviation relative to film thickness variation is +0.08 nm; therefore, it is only necessary to calculate the correction value for the parameters of the process used to achieve a film thickness of -0.08 nm.

[0098] Furthermore, regarding the calculation of the regression coefficients described in step S02, the detailed process can be modified based on the inspection results held in the inspection result holding unit 101, and considering the safety or ease of correction corresponding to the correction of the parameters being corrected. That is, a priority for minimizing the norm (norm minimization priority) can be set, and the detailed process for calculating the correction value can be modified considering this priority. Figure 8 The diagram illustrates the process of calculating the correction value while considering the norm minimization priority.

[0099] First, the regression coefficient calculation unit 103 executes step S11. In step S11, using the results held in the check result holding unit 10, it is determined whether the unit deviation can be calculated using the least squares method (least squares method with equality constraints). Then, if the result of this determination is "yes (YES)", the regression coefficient calculation unit 103 executes step S12. In step S12, the unit deviation (first unit deviation, second unit deviation) of each unit is calculated using the least squares method with equality constraints.

[0100] As mentioned above, when the film thickness inspection results for all combinations of cells that can pass through wafer W within the same set exist, the cell deviation of all cells can be determined using the least squares method with equality constraints. For example, in Figure 9 In (a), an example is shown of a set consisting of four coating units U1 (COT1 to COT4) and four heat treatment units U2 (PAB1 to PAB4). Figure 9 In the set shown in (a), if it is possible to obtain the inspection results of the film thickness of the resist film in all combinations, such as Figure 9 As shown in (b), the cell deviation of each cell can be calculated using the least squares method with equality constraints. That is, using the least squares method with equality constraints, the overall average (the average film thickness within the set) and the cell deviation (equivalent to the difference) of the resist film thickness of each cell relative to the overall average can be calculated. In the above, the case where the film thickness of the resist film in all combinations can be obtained has been explained. However, whether the cell deviation can actually be calculated using the least squares method with equality constraints depends on whether the obtained results are divided into subsets. Therefore, in step S11, a determination is made as to whether the obtained results are divided into subsets. If the determination result in step S11 is "yes", in step S12, the cell deviation and correction value are calculated using the least squares method with equality constraints.

[0101] Next, if the result of the judgment in step S11 is "NO," meaning the check results are not sufficiently consistent and the unit deviation cannot be calculated using the least squares method with equality constraints, the regression coefficient calculation unit 103 executes step S13. In step S13, a judgment is made as to whether the norm minimization priority exists when calculating the unit deviation and correction value for each element (unit group) (the norm minimization priority is different for each element). If the result of this judgment is "Yes," meaning the norm minimization priority exists when calculating the unit deviation and correction value for each element (the norm minimization priority is different for each element), the regression coefficient calculation unit 103 executes step S14. In step S14, the norm is minimized relative to the set target value and the unit deviation is calculated according to the order of the norm minimization priority for each element. On the other hand, if the result of this judgment is "No," meaning the norm minimization priority does not exist when calculating the unit deviation and correction value for each element (the norm minimization priority is the same for each element), the regression coefficient calculation unit 103 executes step S15. In step S15, the cell deviation of each cell is calculated to minimize the norm of the entire feature outside the intercept.

[0102] As mentioned above, Figure 8 This explains how the calculation method can be modified based on whether the least squares method with equality constraints can be used to calculate the unit deviation and whether there is a priority for minimizing the norm of each element. However, in Figure 8 The calculations under the conditions shown (steps S12, S14, S15) can also be concentrated in step S14. That is, steps S11 and S13 can be omitted, and only step S14 can be executed to calculate the unit deviation. For example, as shown in step S12, the solution can be obtained using the least squares method with equality constraints, meaning the solution has no degrees of freedom. In this case, the same solution can be calculated regardless of whether there is a norm minimization priority. Therefore, even if the norm minimization priority is appropriately set, the solution can still be obtained by executing the algorithm corresponding to step S14. Furthermore, when considering the case that the norm minimization priority in step S14 is the same for each element, step S15 can obtain the solution using the same algorithm as step S14. Therefore, even if only step S14 is executed, the solution can be obtained as well as the solution based on... Figure 8 The process calculated the same solution.

[0103] Reference Figures 10-12 Steps S13 to S15 will be explained below. Figure 10 In (a), the inspection results are shown for the set consisting of five coating units U1 (COT1 to COT5) and five heat treatment units U2 (PAB1 to PAB5). Figure 10In the example shown in (a), the film thickness of the resist film was not obtained for all combinations. That is, Figure 10 This indicates the state of Set1, which represents the inspection results of a combination of COT1, COT2, COT3, PAB1, and PAB2, and the state of Set2, which represents the inspection results of a combination of COT4, COT5, PAB3, PAB4, and PAB5. In this state, as... Figure 10 As shown in (b), it is possible to calculate the overall average (equivalent to the set target value), the difference between the overall average and the averages of Set1 and Set2 respectively, and the unit deviations of each unit in Set1 and Set2 based on least squares relative to the set target value. However, the unit deviations of each unit are for the Set units from which the inspection results were obtained. Therefore, the correction value based on this unit deviation is a correction value used to correct the average value of the Set units, and not a correction value corresponding to the correction of the Set units. Furthermore, the obtained inspection results in Figure 10 In the state shown in (a), when trying to calculate the unit deviation of each unit relative to the overall average of the set using the least squares method, there are infinitely many solutions because the equations are insufficient with respect to the unknowns. That is, it is a state in which the unit deviation of the process in each unit cannot be calculated.

[0104] When there are infinitely many solutions using least squares with equality constraints, generally, the solution that minimizes the norm of the explanatory variables is chosen. Here, the overall mean (intercept) and the deviations of each unit are the explanatory variables. Figure 11 Indicates according to Figure 10 The inspection results shown in (a) are calculated by taking the element deviation of each element to minimize the norm of the element deviation, excluding the expected value (intercept) of the average film thickness within the set. In this case, as... Figure 11 As shown, the norm of COT / PAB is 1.572, and the element deviations of COT1~5 and PAB1~5 are 1.278 and 0.915, respectively. The process (computation) for determining the solution under the condition that the norm becomes minimal can be compared with... Figure 8 The step S15 shown corresponds to this. Furthermore, known methods can be used as a specific procedure for determining the solution under the condition that the norm becomes minimal.

[0105] However, in the above Figure 11The results shown minimize the norm outside the intercept of multiple units as a whole, but the priority of corrections for parameters corresponding to the units is not considered. In cases where there is a desire to reduce the norm of the heating temperature of the heat treatment unit U2, as described above, norm minimization is performed to reduce the correction value of the parameter whose correction value is desired, i.e., the correction value of the heating temperature of the heat treatment unit U2. In this embodiment, the heating temperature of the heat treatment unit U2 is processed by calculating unit deviations to minimize the norm.

[0106] As described above, regarding the parameters of each unit, when the norm minimization priority of the unit deviation calculation (correction value calculation) is different, the unit deviation of each unit used to minimize the norm is calculated based on the parameter with the higher norm minimization priority. In this embodiment, the parameters of each unit are the rotation speed of the coating unit U1 and the heating temperature of the heat treatment unit U2. Furthermore, the parameter with the higher norm minimization priority corresponds to the parameter whose correction value is not to be increased to the required level. Parameters (elements) whose correction value is not to be increased to the required level can be exemplified as parameters that are not easy to correct or parameters that would pose some risks if corrected. On the other hand, parameters whose correction value can be increased can be exemplified as parameters that are easy to correct or parameters with low risk when corrected. As described above, when there is a parameter to which the correction value is to be minimized, the parameter to which the element (unit group) belongs is processed with the higher norm minimization priority. Then, when minimizing the norm, the minimization calculation is performed based on the element with the higher norm minimization priority. In the configuration of this embodiment, compared to COT, which uses rotation speed as a parameter, PAB, which uses heating temperature as a parameter, becomes the element with the higher norm minimization priority. Therefore, the elements with high priority for norm minimization are calculated, namely, the unit deviations of the process treatment used to minimize the norm for each unit according to PAB.

[0107] The calculation of cell bias considering norm minimization priority (and) Figure 8 The calculation corresponding to step S14 can be performed, for example, by the following method: Describe the expected value of the average membrane thickness in a set and the cell deviation of the membrane thickness in each cell as explanatory variables (regression coefficients) and the objective function. Then, add an additional objective function that considers the priority of norm minimization, and calculate the regression coefficients by solving a multi-objective optimization problem. Thus, for each cell, after considering the priority of norm minimization, the cell deviation can be calculated to minimize the norm. The calculation of the regression coefficients themselves can use known methods.

[0108] The unit deviation of each unit is calculated according to the above process. Figure 12 It is given in [the document]. Figure 12 In the results shown, with Figure 11 Compared to the results shown, the squared errors are the same, but the element biases of COT1 to COT5 are larger, while the element biases of PAB1 to PAB5 are smaller. Specifically, in Figure 12 In the results shown, the norm of coating unit U1 (COT1~COT5) is 1.681, while the norm of heat treatment unit U2 (PAB1~PAB5) is 0.663.

[0109] When calculating the unit deviations of the process for each unit to minimize the norm in order of priority based on minimizing the norm of elements with higher priority, the norm of the overall unit is not minimized. For example, in Figure 11 In the calculation results shown, the COT / PAB norm is 1.572, which is in contrast to... Figure 12 In the calculation results shown, the COT / PAB norm is 1.807. However, the process treatment of the cells for elements with high norm minimization priority can result in a smaller calculated cell deviation. That is, the norm can be reduced for the cell deviations of the process treatments involved in parameters with high norm minimization priority. This is because calculations are performed to further reduce the cell deviations of elements with high norm minimization priority.

[0110] Furthermore, whether to set a norm minimization priority can be controlled by the correction value calculation unit 102 of the control device 100. When executing step S13, a determination can be made based on information held by this device.

[0111] In this embodiment, the case where a process based on two parameters in two processing units is described, and unit deviations (first unit deviation, second unit deviation) are calculated and corrected accordingly. The two processing units are coating unit U1 and heat treatment unit U2, and the two parameters are rotation speed and heating temperature. However, the same process can be performed when there are three or more processing units and three or more types of parameters. That is, when three levels of norm minimization priority are set for the three processing units (i.e., three process treatments), the unit deviation that minimizes the norm is calculated is repeatedly performed in the same manner, starting from the processing unit with the highest norm minimization priority. Thus, the three unit deviations in the three units performing the three process treatments can be calculated with priority taken into account. Furthermore, when there are four or more types of processing units and parameters, the unit deviations can be calculated with priority taken into account in the same manner. In addition, the norm minimization priority can be set only in a portion of the processing units (a portion of the process treatments).

[0112] Furthermore, the aforementioned substrate processing control method can be implemented at a predetermined time during substrate processing using the substrate processing system 1. For example, processing can be performed at a user-specified time. Additionally, when processing of any batch of substrates is completed, the aforementioned processing can be performed if the simple average of the film thicknesses of the substrates processed in each unit does not deviate from a preset range, based on the film thickness of the closest predetermined number of substrates in that batch. In this case, the correction amount in each unit can also be calculated based on the aforementioned simple average.

[0113] Furthermore, the start of the aforementioned processing can be determined based on the comparison between the 95% confidence interval and the reference value. Specifically, when the processing of any batch of substrates is completed, based on the film thickness measurement results of the closest predetermined number of substrates in that batch, and assuming the cell deviations in each cell are inferred, a 95% confidence interval for the inferred value is calculated. It is permissible to determine whether to proceed with the aforementioned processing if the 95% confidence interval does not contain the reference value that serves as the inferred value. For example, if the ensemble target value is the same as the expected value of the current average film thickness, the trigger for starting the aforementioned substrate processing control method may be the case that the 95% confidence interval of the cell deviations in coating unit U1 or heat treatment unit U2 does not contain the reference value 0. Alternatively, it is permissible to set the ensemble target value differently from the expected value of the average film thickness, for example, assuming that only the first cell is related to the correction of the average film thickness. It is also permissible to use the case that, based on this assumption, the trigger is the case that the 95% confidence interval of the sum of the expected value of the average film thickness and the deviation of the first cell does not contain the ensemble target value that serves as the reference value. In this case, the fact that the 95% confidence interval of the second unit deviation does not include the baseline value of 0 can also be used as a trigger. The above method is just one example and is not limited to it.

[0114] [effect]

[0115] According to the substrate processing control method and substrate processing apparatus of the above embodiments, a dataset is obtained from multiple processed substrates. This dataset includes information identifying a first leveling unit (coating unit U1) that has undergone a first processing, information identifying a second leveling unit (heat treatment unit U2) that has undergone a second processing, and information about characteristic quantities (e.g., film thickness) of the substrate. Furthermore, in the calculation step, information including expected values ​​of the characteristic quantities, leveling unit deviations of the first leveling unit relative to the expected values, and leveling unit deviations of the second leveling unit relative to the expected values ​​are calculated. Furthermore, based on the calculated information, a first parameter in the first unit or a second parameter in the second unit is corrected. By adopting this configuration, leveling unit deviations can be calculated for each of the multiple first processing leveling units and the multiple second processing leveling units, and parameters of each unit can be corrected based on these leveling unit deviations. Therefore, even for substrates that have undergone processing in multiple leveling units such as multiple types of processing units, appropriate corrections relative to target values ​​can be made for each unit using the dataset containing the substrate's characteristic quantities.

[0116] Methods for correcting features of a processed substrate that differ from the target value have been studied. However, no method has been developed to appropriately control the parameters of each processing unit and to what extent they should be corrected, based on the feature values ​​of the substrate after repeated processing of multiple types of processes. In particular, no method has been developed to calculate correction values ​​for multiple processing units that perform multiple types of processes, considering which processing unit causes the feature values ​​of the substrate to change and to what extent. In this regard, according to the substrate processing control method and substrate processing apparatus described above, the leveling unit deviation is calculated for each of the first and second leveling units, and the parameters of each unit are corrected based on the result. Therefore, even for substrates that have undergone processing in multiple leveling units such as multiple types of processing units, it is possible to appropriately correct each unit relative to the target value using a dataset containing the feature values ​​of the substrate.

[0117] Furthermore, in the above-described embodiment, when calculating the first leveling unit deviation in the first leveling unit and the second leveling unit deviation in the second leveling unit, the leveling unit deviation is calculated to minimize the norm other than the expected value of the feature quantity. By adopting the above configuration, for example, even when only a dataset is available where the range of unit deviations for each unit cannot be calculated using existing methods such as least squares, the first leveling unit deviation (first unit deviation) and the second leveling unit deviation (second unit deviation) can still be calculated. Therefore, according to the above configuration, appropriate corrections can be made for each unit relative to the target value. In particular, even when the dataset is insufficient, the unit deviations for each unit can be appropriately calculated from the viewpoint of minimizing the norm, thus enabling more appropriate corrections.

[0118] Furthermore, in the above embodiment, when a norm minimization priority corresponding to the order in which processing to reduce the correction value is prioritized is predetermined, the unit deviations are calculated sequentially from the elements with high norm minimization priority to minimize the norm other than the expected value of the feature quantity. With this configuration, corrections to elements with high norm minimization priority are prevented from including unit deviations from other elements. Therefore, the correction value can be reduced for elements with high norm minimization priority. In the above embodiment, the heating temperature of the heat treatment unit U2, which corresponds to the second parameter, is a parameter belonging to the elements with high norm minimization priority. Therefore, by calculating the correction value from the heat treatment unit U2 in a manner that minimizes the norm of the unit deviation, the correction value of the heating temperature can be reduced.

[0119] Furthermore, as described in the above embodiment, multiple first processing units and multiple second processing units can be divided into sets formed by integrating processing units capable of processing a substrate. In this case, for each set formed by integrating processing units capable of processing a substrate, a set target value is set, and the first unit deviation and the second unit deviation are calculated. Therefore, compared to calculating the unit deviation by considering combinations of processing units that cannot process a substrate, the unit deviation can be calculated with higher accuracy. Even when calculating the unit deviation without considering sets, for example, if substrate processing is performed using first and second processing units contained in different sets, the unit deviation can still be calculated. In this case, there is a possibility of reduced accuracy in calculating the unit deviation. To address this, as described above, by calculating the unit deviation for each set, the unit deviation can be calculated with high accuracy.

[0120] [Other Implementation Methods]

[0121] The above descriptions illustrate various illustrative embodiments. However, the embodiments described are not limited to those shown above, and various omissions, substitutions, and changes can be made. Furthermore, elements from different embodiments can be combined to form other embodiments.

[0122] For example, in the above embodiment, the parameters in each of the plurality of coating units U1 and the plurality of heat treatment units U2 are corrected during the formation of the resist film in the processing module 12. However, the above-described substrate processing control method can also be applied to processes different from the formation of the resist film on the substrate. For example, in the above-described coating and developing apparatus 2, the formation of a lower layer film and an upper layer film are also performed, and the above-described process can also be controlled by the control device 100 while correcting the parameters. Furthermore, the parameter correction performed by the control device 100 can also be applied to substrate processing processes not described in the above embodiments. As described above, the calculation of unit deviations and the correction of parameters based on unit deviations in the processes described in the above embodiments are not particularly limited.

[0123] Furthermore, the characteristic quantity is not limited to the film thickness formed on the substrate. For example, the linewidth of the resist pattern can be used as a characteristic quantity. Moreover, the parameters of the first and second processes can be appropriately changed based on the characteristic quantity. For example, in the above embodiment, the rotational speed in the coating unit U1 for applying the treatment liquid is used as a parameter; however, for other processing units that perform processing while rotating the substrate, the rotational speed can also be selected as a parameter. Furthermore, when performing some processes using a treatment liquid, the characteristics of the treatment liquid can be selected as a parameter. Additionally, a processing condition in one of the processing units can also be selected as a parameter. As described above, the characteristic quantity of the substrate's characteristics can be appropriately selected, and the first and second processes can be appropriately selected based on the characteristic quantity. Furthermore, the first parameter in the first process and the second parameter in the second process can also be appropriately changed based on the characteristic quantity, etc.

[0124] Furthermore, in the above embodiments, such as Figure 6 The diagram illustrates the process of calculating the corrected values ​​of the parameters for each unit after the regression coefficients are calculated, but this process can be modified.

[0125] Furthermore, when the control device 100 calculates the correction value, it does not proceed. Figure 8All steps shown. For example, if only the portion of the dataset that cannot be calculated using the least squares method is available, and the priority of each element is determined, steps S11 and S13 can be omitted. As described above, if the quantity or content of the dataset obtained by the control device 100, the characteristics of the parameters of the processing unit that is the object of calculating the unit deviation and correction value are known in advance, processing can be appropriately omitted based on the information known to the device.

[0126] Furthermore, in the above embodiment, the case where the expected value of the average film thickness, the first unit deviation, and the second unit deviation are processed separately when considering the priority of norm minimization and calculating the correction value for further reducing unit deviation is described. However, it is also possible to integrate a portion of the above three elements into one for processing. Specifically, consider processing the expected value of the average film thickness and the first unit deviation (unit deviation of coating unit U1) as described in the above embodiment as a whole. In this case, the value composed of the expected value (intercept) of the first unit deviation and the average film thickness is processed as the expected value of the film thickness of the first unit, and the objective function is described using the expected value of the film thickness of the first unit and the second unit deviation, and the optimal solution of the above regression coefficients is calculated. The average value of the expected value of the film thickness of the first unit will not become 0, but by replacing norm minimization with distribution minimization, the same effect as norm minimization of the first unit deviation can be obtained.

[0127] Based on the above description, various embodiments of the present invention have been described in this specification for illustrative purposes. It should be understood that various modifications can be made without departing from the scope and spirit of the invention. Therefore, the various embodiments disclosed in this specification are not limiting, and the true scope and spirit are given by the scope of the appended claims.

Claims

1. A substrate processing control method in a substrate processing apparatus, the substrate processing apparatus comprising: The first element comprises a plurality of first leveling units that perform a first processing on the substrate based on a first parameter; The second element comprises multiple second leveling units that perform a second processing on the substrate based on a second parameter. The substrate processing control method is characterized by including: The acquisition step involves acquiring a dataset for each of a plurality of substrates that have undergone the first processing in the first leveling unit and the second processing in the second leveling unit. The dataset includes: information identifying the first leveling unit that has undergone the first processing; information identifying the second leveling unit that has undergone the second processing; and information about feature quantities relating to the characteristics of the substrate. The calculation step, based on a dataset corresponding to each of the plurality of substrates, calculates information including the expected value of the feature quantity, the leveling unit deviation of the first leveling unit relative to the expected value, and the leveling unit deviation of the second leveling unit relative to the expected value; and The correction step, based on the information calculated in the calculation step, corrects the first parameter in each first leveling unit and the second parameter in each second leveling unit. The first leveling unit is a coating unit, and the first parameter is the rotational speed. The second leveling unit is a heat treatment unit, and the second parameter is the heating temperature. The characteristic quantity is film thickness. The leveling unit deviation of the first leveling unit is the deviation of the film thickness change after processing by the coating unit from the expected value. The leveling unit deviation of the second leveling unit is the deviation of the film thickness change after treatment by the heat treatment unit from the expected value.

2. The substrate processing control method as described in claim 1, characterized in that: In the calculation step, based on the dataset corresponding to each of the plurality of substrates, information including the leveling unit deviation of the first leveling unit relative to the expected value and the leveling unit deviation of the second leveling unit relative to the expected value is calculated to minimize the norm other than the expected value of the feature quantity based on the dataset.

3. The substrate processing control method as described in claim 1, characterized in that, Also includes: In the calculation step, given that the norm minimization priority corresponding to the order in which processing to reduce their correction values ​​is prioritized is predetermined for the first and second elements, the cell deviation is calculated sequentially from the elements with the high norm minimization priority based on the dataset, so as to minimize the norm other than the expected value of the average value of the feature quantity.

4. A substrate processing apparatus, characterized in that, include: Multiple first processing units perform first processing on the substrate based on first parameters; Multiple second processing units perform second processing on the substrate based on second parameters; The feature information acquisition unit acquires information about the characteristics of a substrate that has undergone the first processing in any of the plurality of first processing units and the second processing in any of the plurality of second processing units. as well as A control unit that controls the plurality of first processing units and the plurality of second processing units. The control unit acquires a dataset from the feature quantity information acquisition unit for each of the plurality of substrates that have undergone the first processing in any of the plurality of first processing units and then the second processing in any of the plurality of second processing units. The dataset includes: information identifying the first processing unit that underwent the first processing; information identifying the second processing unit that underwent the second processing; and feature quantity information regarding the characteristics of the substrate. The control unit calculates information based on a dataset corresponding to each of the plurality of substrates, including the expected value of the feature quantity, the unit deviation of the first processing unit relative to the expected value, and the unit deviation of the second processing unit relative to the expected value. Based on the calculated information, the control unit corrects the first parameter in each of the first processing units and the second parameter in each of the second processing units. The first processing unit is a coating unit, and the first parameter is the rotational speed. The second processing unit is a heat treatment unit, and the second parameter is temperature. The characteristic quantity is film thickness. The unit deviation of the first processing unit is the deviation of the change in film thickness after processing by the coating unit from the expected value. The unit deviation of the second processing unit is the deviation of the film thickness change after processing by the heat treatment unit from the expected value.

5. A computer-readable storage medium, characterized in that: The device contains a program for implementing the substrate processing control method according to any one of claims 1 to 3.

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