阅读说明：本技术 基片处理控制方法、基片处理装置和存储介质 (Substrate processing control method, substrate processing apparatus, and storage medium ) 是由 鹤田丰久 小西仪纪 于 2020-09-15 设计创作，主要内容包括：本发明提供根据基片处理的状态来适当地控制各种参数的基片处理控制方法、基片处理装置和存储介质。具有包含多个第一水准单元的第一要素和包含的多个第二水准单元的第二要素的基片处理装置中的基片处理控制方法,其包括：获取步骤,其对每个基片获取包含确定进行了第一处理的第一水准单元的信息、确定进行了第二处理的第二水准单元的信息和关于基片的特性的特征量的信息的数据集；计算步骤,其基于数据集,计算包含特征量的预期值、相对于预期值的第一水准单元的水准单元偏差和相对于预期值的第二水准单元的水准单元偏差的信息；以及修正步骤,其基于在计算步骤中计算出的信息,修正第一水准单元的第一参数或者第二水准单元的第二参数。(The invention provides a substrate processing control method, a substrate processing apparatus and a storage medium for appropriately controlling various parameters according to the state of substrate processing. A method for controlling substrate processing in a substrate processing apparatus having a first element including a plurality of first level cells and a second element including a plurality of second level cells, comprising: an acquisition step of acquiring, for each substrate, a data set including information identifying a first level cell on which a first process has been performed, information identifying a second level cell on which a second process has been performed, and information on a characteristic amount of a characteristic of the substrate; a calculation step of calculating information including an expected value of the feature quantity, a level cell deviation of a first level cell from the expected value, and a level cell deviation of a second level cell from the expected value, based on the data set; and a correction step of correcting the first parameter of the first leveling cell or the second parameter of the second leveling cell based on the information calculated in the calculation step.)

1. A substrate processing control method in a substrate processing apparatus, the substrate processing apparatus comprising: a first element including a plurality of first level cells that perform a first process on a substrate based on a first parameter; and a second element comprising a plurality of second level cells for performing a second process on the substrate based on a second parameter,

the substrate processing control method is characterized by comprising:

an acquisition step of acquiring a data set for each of a plurality of substrates on which the first process has been performed in the first leveling unit and the second process has been performed in the second leveling unit, the data set including: determining information of the first level cell on which the first process is performed; determining information of the second level cell on which the second process is performed; and information on a characteristic quantity of a characteristic of the substrate;

a calculation step of calculating information including an expected value of the characteristic amount, a level cell deviation of the first level cell from the expected value, and a level cell deviation of the second level cell from the expected value, based on a data set corresponding to each of the plurality of substrates; and

a correction step of correcting the first parameter in the first leveling cell or the second parameter in the second leveling cell based on the information calculated in the calculation step.

2. The substrate processing control method according to claim 1, wherein:

in the calculating step, information including level cell deviation of the first level cell with respect to the expected value and level cell deviation of the second level cell with respect to the expected value is calculated based on a data set corresponding to each of a plurality of the substrates so that a norm other than an expected value based on the characteristic amount of the data set becomes minimum.

3. The substrate processing control method according to claim 1, further comprising:

in the calculating step, when a norm minimization priority corresponding to an order of giving priority to a process of reducing the correction value is determined in advance for the first element and the second element, unit deviations are calculated in order from an element having a higher norm minimization priority based on the data set so that norms other than an expected value of the average value of the feature amounts become minimum.

4. A substrate processing apparatus, comprising:

a plurality of first processing units that perform first processing based on a first parameter on a substrate;

a plurality of second processing units that perform second processing based on a second parameter on the substrate;

a characteristic amount information acquiring unit that acquires information on characteristics of a substrate on which the first process has been performed in any of the plurality of first processing units and the second process has been performed in any of the plurality of second processing units; and

a control section that controls the plurality of first processing units and the plurality of second processing units,

the control unit acquires, from the feature amount information acquisition unit, a data set for each of a plurality of substrates on which the first process has been performed in any of the plurality of first process units and the second process has been performed in any of the plurality of second process units, the data set including: determining information of the first processing unit on which the first processing is performed; determining information of a second processing unit that has performed the second processing; and information on characteristic quantities of the properties of the substrate,

the control section calculates information including an expected value of the feature quantity, a unit deviation of the first process unit from the expected value, and a unit deviation of the second process unit from the expected value based on a data set corresponding to each of the plurality of substrates,

the control unit corrects the first parameter in the first processing unit or the second parameter in the second processing unit based on the calculated information.

5. A computer-readable storage medium characterized by:

a program for causing an apparatus to execute the substrate processing control method according to any one of claims 1 to 3 is stored.

Technical Field

The invention relates to a substrate processing control method, a substrate processing apparatus and a storage medium.

Background

Patent document 1 discloses a technique of measuring the size of a resist pattern formed on a substrate, and correcting the process temperature of the heat treatment based on the result. Patent document 1 also describes a technique of measuring the size of a resist pattern subjected to heat treatment at a treatment temperature after correction, and correcting the treatment conditions of exposure treatment based on the inspection result.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2009-267144

Disclosure of Invention

Technical problem to be solved by the invention

The present invention provides a technique of appropriately controlling various parameters according to the state of substrate processing.

Technical solution for solving technical problem

A substrate processing control method according to an aspect of the present invention is a substrate processing control method in a substrate processing apparatus including: a first element including a plurality of first level cells that perform a first process on a substrate based on a first parameter; and a second element including a plurality of second level cells for performing a second process on the substrate based on a second parameter, the substrate process control method including: an acquisition step of acquiring a data set for each of a plurality of substrates on which the first process has been performed in the first leveling unit and the second process has been performed in the second leveling unit, the data set including: determining information of the first level cell on which the first process is performed; information specifying the second level cell on which the second processing has been performed; and information on characteristic quantities of the characteristics of the substrate; a calculation step of calculating information including an expected value of the characteristic amount, a level cell deviation of the first level cell from the expected value, and a level cell deviation of the second level cell from the expected value, based on a data set corresponding to each of the plurality of substrates; and a correction step of correcting the first parameter in the first leveling cell or the second parameter in the second leveling cell based on the information calculated in the calculation step.

Effects of the invention

In accordance with the present invention, a technique is provided for appropriately controlling various parameters according to the state of substrate processing.

Drawings

Fig. 1 is a schematic diagram showing an example of the schematic configuration of a substrate processing system.

Fig. 2 is a schematic view showing an example of the coating and developing apparatus.

Fig. 3 is a schematic diagram showing an example of the inspection unit.

Fig. 4 is a block diagram showing an example of a functional configuration of the control device.

Fig. 5 is a block diagram showing an example of the hardware configuration of the control device.

Fig. 6 is a flowchart showing an example of control performed by the control device.

Fig. 7 (a) and 7 (b) are diagrams for explaining an example of the correction of the film thickness.

Fig. 8 is a flowchart showing an example of a method of calculating the cell deviation by the control device.

Fig. 9 (a) and 9 (b) are diagrams showing an example of the inspection result and the calculation result of the cell deviation.

Fig. 10 (a) and 10 (b) are diagrams showing an example of the inspection result and the calculation result of the cell deviation.

Fig. 11 is a diagram showing an example of the calculation result of the cell deviation.

Fig. 12 is a diagram showing an example of the calculation result of the cell deviation.

Description of the reference numerals

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 … … protocol retention portion; unit 107 … … control unit; a U1 … … coating unit; a U2 … … heat treatment unit; u3 … … checks the cells.

Detailed Description

Various exemplary embodiments will be described below.

In one exemplary embodiment, a substrate processing control method is a substrate processing control method in a substrate processing apparatus including: a first element including a plurality of first level cells that perform a first process on a substrate based on a first parameter; and a second element including a plurality of second level cells for performing a second process on the substrate based on a second parameter, the substrate process control method including: an acquisition step of acquiring a data set for each of a plurality of substrates on which the first process has been performed in the first leveling unit and the second process has been performed in the second leveling unit, the data set including: determining information of the first level cell on which the first process is performed; information specifying the second level cell on which the second processing has been performed; and information on characteristic quantities of the characteristics of the substrate; a calculation step of calculating information including an expected value of the characteristic amount, a level cell deviation of the first level cell from the expected value, and a level cell deviation of the second level cell from the expected value, based on a data set corresponding to each of the plurality of substrates; and a correction step of correcting the first parameter in the first leveling cell or the second parameter in the second leveling cell based on the information calculated in the calculation step.

In the above substrate processing control method, a data set including information identifying the first level cell on which the first process is performed, information identifying the second level cell on which the second process is performed, and information on the characteristic amount of the characteristic of the substrate can be obtained. Then, based on the data set, in the calculating step, information including an expected value of the characteristic amount, a level cell deviation of a first level cell from the expected value, and a level cell deviation of a second level cell from the expected value can be calculated. Further, based on the calculated information, the first parameter in the first level cell or the second parameter in the second level cell can be corrected. With this configuration, the parameter can be corrected based on the expected value of the feature amount and the level deviation calculated for the first level cell and the second level cell. Therefore, even for a substrate that has been processed in a plurality of leveling cells, such as a plurality of types of processing cells, correction can be appropriately performed for each cell with respect to a target value using a data set including feature amounts of the substrate.

In the calculating step, information including a level cell deviation of the first level cell with respect to the expected value and a level cell deviation of the second level cell with respect to the expected value is calculated based on a data set corresponding to each of the plurality of substrates so that a norm other than an expected value based on the characteristic amount of the data set is minimized.

In the above configuration, when the first level cell deviation in the first level cell and the second level cell deviation in the second level cell are calculated, the level cell deviation is calculated so that the norm other than the expected value of the characteristic amount becomes minimum. Thus, for example, even when only a data set in which the range of cell deviation for each cell cannot be calculated by a conventional method such as the least square method is obtained, the first level cell deviation and the second level cell deviation can be calculated. Therefore, the correction for each unit with respect to the expected value of the feature amount can be appropriately performed.

In the calculating step, when a norm minimization priority corresponding to an order of prioritizing the process of reducing the correction value is determined in advance for the first element and the second element, the cell deviation may be calculated in order from the element having the highest norm minimization priority based on the data set so that norms other than an expected value of the average value of the feature amounts are minimized.

When the norm minimization priority corresponding to the order in which the processing for reducing the correction value is prioritized is determined in advance, the cell deviation is calculated in order from the element having the higher norm minimization priority so that the norm becomes the minimum. With this configuration, it is possible to prevent the element having a high norm minimization priority from being corrected to include a cell deviation derived from another element. Therefore, the correction value can be reduced for the element having the higher norm minimization priority.

In another exemplary embodiment, a substrate processing apparatus includes: a plurality of first processing units that perform first processing based on a first parameter on a substrate; a plurality of second processing units that perform second processing based on a second parameter on the substrate; a characteristic amount information acquiring unit that acquires information on characteristics of a substrate on which the first process has been performed by any of the plurality of first processing units and the second process has been performed by 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, wherein the control unit acquires a data set from the characteristic amount information acquisition unit for each of a plurality of substrates on which the second processing has been performed by any of the plurality of second processing units after the first processing has been performed by any of the plurality of first processing units, the data set including: information for specifying the first processing unit on which the first processing has been performed; information for specifying a second processing unit that has performed the second processing; and information on a feature value of a characteristic of the substrate, wherein the control unit calculates information including an expected value of the feature value, a unit deviation of the first processing unit from the expected value, and a unit deviation of the second processing unit from the expected value based on a data set corresponding to each of the plurality of substrates, and corrects the first parameter in the first processing unit or the second parameter in the second processing unit based on the calculated information.

In another exemplary embodiment, the storage medium stores a program for causing an apparatus to execute the substrate processing control method described above.

Various exemplary embodiments will be described below with reference to the drawings. In the description, the same elements or elements having the same function are denoted by the same reference numerals, and redundant description thereof is omitted.

[ substrate processing System ]

The substrate processing system 1 is a system for forming a photosensitive coating film on a substrate, exposing the photosensitive coating film, and developing the photosensitive coating film. The substrate to be processed is, for example, a semiconductor wafer W.

The substrate processing system 1 includes a coating and developing apparatus 2 and an exposure apparatus 3. The exposure apparatus 3 performs exposure processing of a resist film (photosensitive coating film) formed on a wafer W (substrate). Specifically, the exposure apparatus 3 irradiates the portion of the resist film to be exposed with energy rays by a method such as liquid immersion exposure. The coating and developing apparatus 2 performs a process of forming a resist film on the surface of the wafer W (substrate) before the exposure process by the exposure apparatus 3, and performs a developing process of the resist film after the exposure process.

[ substrate processing apparatus ]

Hereinafter, the configuration of the coating and developing apparatus 2 will be described as an example of the substrate processing apparatus. As shown in fig. 1 and 2, the coating and developing apparatus 2 includes a carrier block 4, a process block 5, an interface block 6, and a control section 100.

The carrier block 4 introduces the wafer W into the coating and developing apparatus 2 and introduces the wafer W from the coating and developing apparatus 2. For example, the carrier block 4 can support a plurality of carriers C (storage sections) for wafers W, and has a transport device a1 including a transfer arm built therein. The carrier C receives a plurality of circular wafers W, for example. The transfer device a1 takes out the wafer W from the carrier C and delivers it to the processing block 5, and takes in the wafer W from the processing block 5 and returns it to the carrier C. The processing block 5 comprises a plurality of processing modules 11, 12, 13, 14.

The process module 11 includes a plurality of coating units U1, a plurality of heat treatment units U2, a plurality of inspection units U3, and a transfer device A3 for transferring the wafers W to the units. The process module 11 forms an underlying film on the surface of the wafer W using the coating unit U1 and the heat treatment unit U2. The coating unit U1 of the process module 11 coats the processing liquid for forming the lower layer film on the wafer W while rotating the wafer W at a predetermined rotation speed, for example. The heat treatment unit U2 of the process module 11 performs various heat treatments accompanied by formation of an underlayer film. The heat treatment unit U2 incorporates, for example, a hot plate and a cooling plate, and performs heat treatment by heating the wafer W to a predetermined heating temperature with the hot plate and cooling the heated wafer W with the cooling plate. The inspection unit U3 performs a process for inspecting the state of the surface of the wafer W, and acquires information on, for example, the film thickness as information indicating the state of the surface of the wafer W.

The process module 12 includes a plurality of coating units U1, a plurality of heat treatment units U2, a plurality of inspection units U3, and a transfer device A3 for transferring the wafers W to the units. The process module 12 forms a resist film on the lower layer film using the coating unit U1 and the heat treatment unit U2. The processing module 12 is sometimes referred to as a COT module. The coating unit U1 of the process module is sometimes referred to as a COT unit. The coating unit U1 of the process module 12 forms a coating film on the surface of the wafer W by coating the lower layer film with the treatment liquid for forming a resist film. The heat treatment unit U2 of the process module 12 performs various heat treatments accompanied by the formation of a resist film. The heat treatment unit U2 of the process module 12 performs heat treatment (PAB: Pre-Applied cake) at a predetermined heating temperature on the wafer W on which the coating film is formed, thereby forming a resist film. The inspection unit U3 performs a process for inspecting the state of the surface of the wafer W, and acquires, for example, information relating to the film thickness as information indicating the state of the surface of the wafer W.

The process module 13 includes a plurality of coating units U1, a plurality of heat treatment units U2, a plurality of inspection units U3, and a transfer device A3 for transferring the wafers W to the units. The process module 13 forms an upper layer film on the resist film using the coating unit U1 and the heat treatment unit U2. The coating unit U1 of the process module 13 coats the resist film with the liquid for forming the upper layer film while rotating the wafer W at a predetermined rotation speed, for example. The heat treatment unit U2 of the process module 13 performs various heat treatments accompanied by the formation of an upper layer film. The inspection unit U3 performs a process for inspecting the state of the surface of the wafer W, and acquires, for example, information relating to the film thickness as information indicating the state of the surface of the wafer W.

The process module 14 includes a plurality of coating units U1, a plurality of heat treatment units U2, and a transfer device A3 for transferring the wafers W to the units. The process module 14 performs a developing process of the exposed resist film R with the coating unit U1 and the heat treatment unit U2. The coating unit U1 of the process module 14 applies the developer to the surface of the exposed wafer W while rotating the wafer W at a predetermined rotation speed, for example, and then washes the wafer W with a rinse solution to perform a developing process of the resist film R. The heat treatment unit U2 of the process module 14 performs various heat treatments along with the development treatment. Specific examples of the heat treatment include heat treatment before development treatment (PEB: Post Exposure Bake), heat treatment after development treatment (PB: Post Bake), and the like.

A shelf unit U10 is provided on the carrier block 4 side in the processing block 5. The shelving unit U10 is divided into a plurality of cells arranged in the up-down direction. A conveyor a7 including a lift arm is provided in the vicinity of the rack unit U10. The transfer device a7 lifts and lowers the wafers W between the cells of the shelf unit U10.

A shelf unit U11 is provided on the interface block 6 side in the processing block 5. The shelving unit U11 is divided into a plurality of cells arranged in the up-down direction.

The interface block 6 performs transfer of the substrate W between it and the exposure apparatus 3. For example, the interface block 6 is provided with a transport device A8 including a transfer arm therein, and is connected to the exposure apparatus 3. The transfer apparatus A8 transfers the wafer W placed in the rack unit U11 to the exposure apparatus 3, and receives the wafer W from the exposure apparatus 3 and returns the wafer W to the rack unit U11.

[ inspection Unit ]

The inspection units U3 included in the processing modules 11 to 13 will be described. The inspection unit U3 acquires information on the film thickness of the film (lower layer film, resist film, or upper layer film) formed by the coating unit U1 and the heat treatment unit U2. In the present embodiment, the film thickness is information on the characteristics of the substrate, and is used as a feature quantity indicating the characteristics of the substrate on which the film is formed.

As shown in fig. 3, the inspection unit U3 includes a housing 30, a holding portion 31, a linear driving portion 32, an imaging portion 33, and a light projecting reflection portion 34. The holding portion 31 holds the wafer W horizontally. The linear driving unit 32 moves the holding unit 31 along a horizontal linear path using, for example, an electric motor or the like as a power source. The imaging unit 33 includes a camera 35 such as a CCD camera. The camera 35 is provided on one end side in the inspection unit U3 in the moving direction of the holding portion 31, and faces the other end side in the moving direction. The light projection reflector 34 projects light in the imaging range, and guides the reflected light from the imaging range to the camera 35. The light projection reflector 34 has a half mirror 36 and a light source 37, for example. The half mirror 36 is provided at a position higher than the holding portion 31 in the middle of the movement range of the linear driving portion 32, and reflects light from below toward the camera 35. The light source 37 is provided on the half mirror 36, and irradiates illumination light downward through the half mirror 36.

The inspection unit U3 operates in the following manner to acquire image data of the surface of the wafer W. First, the linear driving unit 32 moves the imaging unit 33. Thereby, the wafer W passes under the half mirror 36. In this passage, the reflected light from each portion of the front surface of the wafer W is sequentially sent to the camera 35. The camera 35 images the reflected light from each portion of the front surface of the wafer W to acquire image data of the front surface of the wafer W. When the film thickness of the film formed on the front surface of the wafer W changes, the image data of the front surface of the wafer W captured by the camera 35 changes, for example, the color of the front surface of the wafer W changes according to the film thickness. That is, acquiring image data of the front surface of the wafer W corresponds to acquiring information on the film thickness of the film formed on the front surface of the wafer W. The method of calculating the film thickness from the image data is not particularly limited.

The image data acquired by the camera 35 is transmitted to the control device 100. The control device 100 can estimate the film thickness of the film on the front surface of the wafer W based on the image data, and the estimated result is held in the control device 100 as the inspection result.

[ control device ]

An example of the control device 100 will be described in detail. The control device 100 controls each element included in the coating and developing device 2. The control device 100 is configured to be able to execute a process including a step of forming each film described above on the surface of the wafer W and a step of performing a development process. The control device 100 is configured to be able to perform correction of parameters related to the process treatment and the like based on the result of the process treatment. Details of the above-described process treatment and the like will be described later.

As shown in fig. 4, the control device 100 includes, as functional components, an inspection result holding unit 101, a correction value calculation unit 102, a recipe holding unit 106, and a unit control unit 107. The correction value calculation unit 102 includes a regression coefficient calculation unit 103 and a parameter correction value calculation unit 104.

The control device 100 can change the control contents in the coating unit U1 and the heat treatment unit U2 based on the inspection result of the inspection unit U3. This point will be described with reference to fig. 4. In the following embodiment, control of the process module 12 for forming a resist film on the wafer W will be described as an example. The process module 12 performs a process (first process) related to the coating of the process liquid in the coating unit U1 (first process unit) and a process (second process) related to the heat treatment of the process liquid in the heat treatment unit U2 (second process unit) on the wafer W.

The inspection result holding unit 101 has a function of acquiring and holding the inspection result of the inspection unit U3, that is, the inspection result concerning the resist film on the surface of the wafer W from the inspection unit U3. Further, in the inspection result holding section 101, information for determining in which cell (coating cell U1 and heat treatment cell U2) the wafer W corresponding to the inspection result is processed is acquired based on the process recipe held in the recipe holding section 106 described later. The inspection result holding section 101 acquires and holds the above-described information in association with the inspection result as a data set relating to one substrate. A series of information (data set) of each substrate held by the inspection result holding section 101 can be used for calculation of the correction value by the correction value calculation section 102.

The correction value calculation section 102 has a function of calculating a correction value based on a data set including the inspection result held in the inspection result holding section 101. The correction value calculation by the correction value calculation unit 102 is performed by the regression coefficient calculation unit 103 and the parameter correction value calculation unit 104. The regression coefficient calculation unit 103 calculates an expected value of the collective average film thickness (characteristic amount), an expected value of the film thickness variation among the coating units U1, and an expected value of the film thickness variation among the heat treatment units U2 by regression calculation. Further, in the parameter correction value calculation section 104, the calculation of the correction value of the parameter for each cell is performed based on the value calculated in the regression coefficient calculation section 103. Details of the calculation in each section are described later. The correction value calculation unit 102 calculates correction values corresponding to each of the plurality of coating units U1 and the plurality of heat treatment units U2 included in the process module 12 to be processed.

The recipe holding unit 106 has a function of holding a process recipe of the process module 12. In the recipe, it is determined in which cell (coating unit U1 and heat treatment unit U2) each wafer W is processed, and various parameters at the time of processing in each cell are specified.

The unit control unit 107 has a function of controlling each unit to perform a process in a state where the process recipe held in the recipe holding unit 106 uses the correction value calculated in the correction value calculation unit 102.

Next, calculation of the correction value and control using the correction value performed by the control device 100 will be described with reference to fig. 4. As described above, the process module 12 includes the plurality of coating units U1 and the plurality of heat treatment units U2. In fig. 4, coating units U1 are represented as COT1, COT2, and COT3 … …, respectively. Further, the heat-treating units U2 were represented as PAB1, PAB2, and PAB3 … …, respectively. In the process module 12, the wafer W is transferred to and from the coating unit U1, the heat treatment unit U2, and the inspection unit U3 in this order, and a resist film is formed on the surface of the wafer W by performing a predetermined process in each unit. The recipe held by the recipe holder 106 of the control device 100 determines which of the plurality of coating units U1(COT1 and COT2 … …) and the heat treatment unit U2(PAB1 and PAB2 … …) the wafer W passes through. Furthermore, which treatment is carried out in each unit is also determined by the process recipe.

The plurality of coating units U1 and the plurality of heat treatment units U2 included in the process module 12 can process wafers W by integrating units that can constitute a path of one wafer W. The wafers W charged into the certain coating unit U1 (for example, COT1) may not be charged into all the heat treatment units U2 due to the structural reasons of the process modules 12 or the functional reasons of the apparatus, etc. That is, the wafer W loaded into the predetermined coating unit U1 (for example, COT1) is subjected to the process recipe in which a part of the predetermined heat treatment unit U2 is loaded in advance. That is, the combination of the coating unit U1 and the heat treatment unit U2 through which one wafer W can pass is not randomly selected from all the units but is selected within a certain set. The path of the wafer W is set in the recipe in this manner. As described above, the plurality of coating units U1 and the plurality of heat treatment units U2 included in the process module 12 can be divided into a plurality of groups for processing the same wafer W by integrating the units for processing the same wafer W. FIG. 4 shows a state where COT1 to COT4 and PABs 1 to PAB4 form a single group G1. In such a state, the same cell group included in one set G1 is referred to as an "element" as in COT1 to COT4 or PAB1 to PAB 4. The 2 cells COT1 and COT2 are referred to as "leveling cells", respectively. That is, the first element (COT group) includes a plurality of first level cells (coating cells U1), and the second element (PAB group) includes a plurality of second level cells (heat treatment cells U2). Fig. 4 shows a state in which 2 sets G2 and G3 each including a cell different from the cell included in the set G1 are present. In the process module 12, a resist film is formed on one wafer W in the coating unit U1 and the heat treatment unit U2 included in any one of the groups G1 to G3, and the wafer W is inspected in the inspection unit U3.

However, in the case where the process module 12 has a plurality of coating units U1 and heat treatment units U2, in the case where the respective units perform substrate processing under the same process conditions so that the resist films become uniform, dispersion occurs in the films formed depending on the characteristics of the units and the like.

When a resist film is formed on the front surface of the wafer W, the thickness of the film formed on the front surface changes depending on the rotation speed of the wafer W when the processing liquid is applied, for example, in the coating unit U1. Therefore, when the plurality of coating units U1 are operated by specifying the same parameter (rotation speed), there is a possibility that the film thickness of the coating may vary due to an influence other than the unit temperature. In the heat treatment unit U2, the film thickness formed on the surface changes depending on the heating temperature of the wafer W during the heat treatment. However, when the plurality of heat treatment units U2 are operated with the same parameter (heating temperature) specified, the temperature of the wafer W may slightly vary between the units. If the temperature of the wafer W varies between the units, the thickness of the resist film formed on the wafer W by curing may vary. As described above, even if the process recipe for forming a resist film having a predetermined film thickness is the same, if there is variation in the characteristics of each cell, there is a possibility that the film thickness of the resist film may vary due to the influence of the variation. That is, depending on which unit the wafer W is processed through, a state in which the film thickness of the resist film differs between the wafers W may occur.

However, when a film thickness does not become a desired value but a constant difference occurs in a process according to a recipe due to the influence of the characteristics of a certain cell, a correction value for correcting the difference (from the desired value) derived from the cell is calculated for the cell. Then, by controlling the cell using the parameter in consideration of the correction value, the variation in film thickness due to the characteristics of the cell can be reduced. The cell control unit 107 corrects the parameters of the cell determined by the process recipe held by the recipe holding unit 106 based on the correction value, and then controls each cell using the corrected parameters. With this configuration, the unit can be controlled while reflecting the correction value.

However, the wafers W are not all processed by the same unit, but are processed by any one of the coating units U1 and any one of the heat treatment units U2 included in one set (any one of G1 to G3). Therefore, although there are wafers W passing through the same path, the processing units for each wafer W are different. Therefore, when the inspection result that the film thickness of a certain wafer W is different from the film thickness preset in the recipe is obtained, it is necessary to correct (at least one of) the coating unit U1 or the heat treatment unit U2 that processed the wafer W.

However, it is difficult to specifically determine which unit is subjected to which degree of correction so that the film thickness approaches the target value. The film thicknesses of the wafers W processed in the other cells are compared, and based on this, the characteristics of the respective cells can be estimated. However, it is necessary to consider the influence of the film thickness of the wafer W processed in another cell including the characteristics of the other cell. In a module that performs a plurality of process processes, such as the process module 12, it may be difficult to determine which stage of the plurality of process processes the characteristics of the finished product (for example, the film thickness of the resist film) has been affected by.

In the case where a plurality of coating units U1 and a plurality of heat treatment units U2 are included in the same set as in the set G1 of the process modules 12, it is possible to determine which unit has an influence on the film thickness when a predetermined inspection result is present. That is, the deviation per cell (cell deviation) can be determined from a predetermined inspection result. The unit deviation herein refers to a deviation of a film thickness variation amount from an expected value after the process is performed by each unit. The film thickness variation of the coating unit U1 is the film thickness of the coating amount of the processing liquid, and the film thickness variation of the heat treatment unit U2 is the film thickness variation before and after the heat treatment. Cell deviation can also be referred to as level cell deviation. The cell deviation of the coating cell U1 may be referred to as a first level cell deviation, and the cell deviation of the heat treatment cell U2 may be referred to as a second level cell deviation.

Specifically, for example, when there is a film thickness inspection result corresponding to a combination of all units through which the wafer W can pass in the set, it is possible to determine which unit has an influence on the film thickness by using the least square method. That is, in the case of COT1 to COT4 and PAB1 to PAB4, when the results of 16 types of all combinations match, the cell deviation of each cell can be determined. In another example, when there is no combination of all the cells, the combination of the cells through which the wafer W has passed can be used as a series of inspection results (predetermined inspection results) included in one small set unless the combination of the cells is divided into a plurality of small sets. Where "small sets" are associated with each other, also can be referred to as subsets. However, the evaluation cannot be performed for a cell that does not pass the wafer W (a cell that does not have an inspection result).

However, even in the same set of units, there is a case where a combination of the coating unit and the heat treatment unit specified in the flow of the process of the wafer W in the apparatus is not executed. In such a case, even with the same set of cells, the combination of cells through which the wafer W has passed is divided into a plurality of small sets (subsets), and it is difficult to determine the cell deviation. In this case, after some inference is applied, it is required to calculate a correction value for each cell.

In addition, when the unit control is performed by applying some correction value to the rotation speed of the coating unit U1 or the heating temperature of the heat treatment unit U2 in order to maintain the film thickness of the wafer W at a predetermined value, there is a difference in the ease of control between the coating unit U1 and the heat treatment unit U2. For example, although the control of changing the rotation speed in the coating unit U1 can be performed relatively easily, the control of changing the heating temperature in the heat treatment unit U2 may be difficult compared to the change in the rotation speed. Therefore, when the correction value for each cell is not accurately calculated, but when the correction value for each cell is calculated after some estimation is performed, it is sometimes required to estimate the correction value of the heating temperature so as to be small. As described above, when 2-stage processes (coating and heat treatment) using 2 different kinds of parameters are performed so that the film thickness of the wafer W becomes a predetermined value, the priority for performing the correction may be determined.

Therefore, in the control device 100, a concept called an aggregate target value (film thickness as an aggregate target) is set when the coating unit U1 and the heat treatment unit U2 in the process module 12 are corrected. Then, in the control device 100, the average value of the film thicknesses of the respective sets is made to approach the set target value, and correction values for reducing the cell deviation of the respective cells are calculated. The set target value may be a film thickness that is a target value specified by a user, or may be an average of all units included in any one of a plurality of sets included in the apparatus. The collective target value may be an average value of the film thicknesses of the respective collections, and the correction value may be calculated so as to reduce only the cell deviation without correcting the average value of the film thicknesses of the collections. Among the above corrections, the correction for reducing the cell deviation is also referred to as an intra-layer average correction. When the collective target value is different from the average value of the current film thicknesses, correction is performed so that the average expected value of the film thicknesses becomes the collective target value, and this correction is referred to as target correction.

Then, based on the correction values, correction values for the coating units U1 and the heat treatment units U2 in the processing module 12 are calculated. The regression coefficient calculation unit 103 and the parameter correction value calculation unit 104 calculate the correction value at each stage. The details of the calculation of the correction values at the respective stages will be described later.

The control device 100 is constituted by one or more control computers, for example. For example, the control device 100 has a circuit 120 shown in fig. 5. The circuit 120 has one or more processors 121, a memory 122, a storage 123, and an input-output port 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 execute a process flow described later. The storage medium may be a removable medium such as a nonvolatile semiconductor memory, a magnetic disk, and an optical disk. The memory 122 temporarily stores the program loaded from the storage medium of the memory 123 and the operation result of the processor 121. The processor 121 and the memory 122 cooperate to execute the programs, thereby constituting the functional modules. The input/output port 124 performs input/output of an electric signal with a component to be controlled in accordance with an instruction from the processor 121.

The hardware configuration of the control unit 100 is not necessarily limited to the configuration of each functional block by a program. For example, each functional block of the control unit 100 may be formed of a dedicated logic Circuit or an ASIC (Application Specific Integrated Circuit) Integrated therewith.

[ Process flow ]

Next, a process flow performed in the coating and developing apparatus 2 will be described as an example of the coating and developing process.

In the process flow, the controller 100 first controls the transfer device a1 to transfer the wafers W to be processed in the carrier C to the shelf unit U10, and controls the transfer device a7 to place the wafers W in the chambers for the processing modules 11.

Next, the control device 100 controls the transfer device a3 to transfer the wafers W of the shelf unit U10 to the coating unit U1 and the heat treatment unit U2 in the process module 11. Further, the control device 100 controls the coating unit U1 and the heat treatment unit U2 to form an underlayer film on the surface of the wafer W. After the formation of the lower layer film, the controller 100 may control the transfer device a3 to transfer the wafer W to the inspection unit U3, and inspect the state of the surface of the wafer W (for example, the film thickness of the lower layer film) using the inspection unit U3. Thereafter, the controller 100 controls the transfer device A3 to return the wafer W having the lower layer film formed thereon to the shelf unit U10, and controls the transfer device a7 to place the wafer W in the chamber for the process module 12.

Next, the control device 100 controls the transfer device a3 to transfer the wafers W of the shelf unit U10 to the coating unit U1 and the heat treatment unit U2 in the process module 12. Further, the control device 100 controls the coating unit U1 and the heat treatment unit U2 to form a resist film R on the lower layer film of the wafer W. For example, the controller 100 controls the coating unit U1 to apply the processing liquid for forming a resist film on the lower layer film of the wafer W to form a resist coating film. Next, the controller 100 controls the heat treatment unit U2 to perform heat treatment on the resist film. After the resist film R is formed, the control device 100 controls the transfer device a3 to transfer the wafer W to the inspection unit U3, and controls to inspect the state of the surface of the wafer W (for example, the film thickness of the resist film) using the inspection unit U3.

After obtaining the inspection result from the inspection unit U3, the control device 100 calculates the expected value of the average film thickness in the set and the unit deviation between the coating unit U1 and the heat treatment unit U2 from the inspection result. Specifically, the cell deviation (first cell deviation, second cell 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) was calculated. Then, the control device 100 determines a correction value of the film thickness from the calculated cell deviation, and controls the rotation speed or the heating temperature in each cell by correcting the value.

Thereafter, the controller 100 controls the transfer device A3 to return the wafer W to the shelf unit U10, and controls the transfer device a7 to dispose the wafer W in a unit for the process module 13.

Next, the controller 100 controls the transfer device a3 to transfer the wafer W in the shelf unit U10 to each unit in the process 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. After the upper layer film is formed, the controller 100 may control the transfer device a3 to transfer the wafer W to the inspection unit U3, and inspect the state of the surface of the wafer W (for example, the film thickness of the upper layer film) using the inspection unit U3. Thereafter, the control device 100 controls the transfer device a3 to transfer the wafers W to the shelf unit U11.

Subsequently, the controller 100 controls the transfer device A8 to transfer the wafers W in the rack unit U11 to the exposure device 3. Thereafter, the controller 100 controls the transfer device A8 to receive the wafer W subjected to the exposure process from the exposure apparatus 3 and arrange the wafer W in the shelf unit U11 for the process module 14.

Next, the controller 100 controls the transfer device a3 to transfer the wafer W in the shelf unit U11 to each unit in the process module 14, and controls the coating unit U1 and the heat treatment unit U2 to perform the developing process on the resist film R of the wafer W. Thereafter, the controller 100 controls the transporter A3 to return the wafer W to the shelf unit U10, and controls the transporter A7 and the transporter A1 to return the wafer W to the carrier C. The process is completed.

[ method for controlling substrate treatment ]

Next, a substrate processing control method performed by the control device 100 on the processing module 12 will be described with reference to fig. 6 to 12. The substrate processing control method comprises the following steps: a calculation flow of a correction value of the rotation speed (first parameter) of the coating unit U1 (first processing unit) and the heating temperature (second parameter) of the heat treatment unit U2 (second processing unit); and the control flow of each unit.

As shown in fig. 6, first, the control device 100 executes step S01 (acquisition step). In step S01, the inspection result (inspection result of film thickness) of the wafer W is acquired from the inspection unit U3 and held in the inspection result holding unit 101. At this time, the inspection result holding unit 101 acquires information identifying the units (coating unit U1 and heat treatment unit U2) in which the wafer W is processed, from the recipe holding unit 106, for the wafer W whose inspection result is acquired. Thereby, a series of data sets are acquired in the control device 100. Further, information for identifying the units (the coating unit U1 and the heat treatment unit U2) in which the wafer W has been processed may also be acquired from the inspection unit U3.

Next, the control device 100 executes step S02 (calculation step). In step S02, the regression coefficient calculation unit 103 of the correction value calculation unit 102 creates a model of the film thickness change based on the inspection result held in the inspection result holding unit 101. Specifically, the regression coefficient calculation unit 103 creates a model of the film thickness change corresponding to the change in the setting of the parameter in each cell when controlling the film thickness of each process in the coating cell U1 and the heat treatment cell U2 in the set determined. Then, based on the model, a function (objective function) for inferring the expected value of the average film thickness, the expected value of the cell deviation of the coating unit U1, and the expected value of the cell deviation of the heat-treated unit U2 in the determined set is set. Then, the optimum solutions of the expected value of the average film thickness, the cell deviation of the coating unit U1, and the cell deviation of the heat treatment unit U2 were obtained so that the expected value of the average film thickness approached the above-described collective target value, and the cell deviations of the coating unit U1 and the heat treatment unit U2 approached 0. The optimum solutions of the expected value of the average film thickness, the cell deviation of the coating unit U1, and the cell deviation of the heat treatment unit U2 correspond to regression coefficients.

The optimal solutions for the expected values of the average film thickness, the cell deviation of the coating unit U1, and the cell deviation of the heat treatment unit U2 can be obtained by solving a least squares problem with an equation constraint. The equality constrained least squares problem is based on a model that presets control of film thickness in a set containing multiple coating units U1 and multiple thermal processing units U2. However, sometimes the above-mentioned least squares with equality constraints problem is not uniquely determined due to different conditions or due to insufficient orders. Therefore, the constraint condition that the norm of the cell deviation of the coating cell U1 and the norm of the cell deviation of the heat treatment cell U2 become minimum is added to the expected value of the average film thickness, and the constraint condition is formulated as one of the multi-objective optimization problems. Thus, by solving the above-described multi-purpose optimization problem, regression coefficients can be calculated. In the above constraint, the priority of minimizing the norm of the cell deviation of the coating cell U1 and the cell deviation of the heat treatment cell U2 (norm minimization priority) may be higher than the norm minimization priority of the average film thickness.

After obtaining the optimum solution of the expected value of the average film thickness, the cell deviation of the coating unit U1, and the cell deviation of the heat treatment unit U2 by solving the above-described multi-purpose optimization problem, the control device 100 executes step S03 (correction step). In step S03, based on the optimal solution, a correction value of the parameter corresponding to the optimal solution is obtained. The parameter correction value calculation unit 104 calculates the correction value of the parameter. By executing step S03, correction values of the film thicknesses in the respective cells are determined. Therefore, the correction value of the parameter corresponding to the correction value of the film thickness is calculated. The correction value of the parameter of each cell can be calculated based on the relationship between the film thickness and the parameter of each cell, which is previously held by the control device 100. That is, it is previously obtained how much the film thickness changes when the parameter (norm) of each cell is changed, and the magnitude of the film thickness to be changed by correction is acquired from the cell deviation, whereby the correction value of the parameter can be obtained from the relationship obtained in advance.

Next, the control device 100 executes step S04 (correction step). In step S04, the cell control unit 107 controls each cell (coating cell U1 or heat treatment cell U2) based on the process recipe held in the recipe 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 section 102 for the parameter of each unit included in the recipe, the corrected parameter can be calculated. The cell control unit 107 controls each cell based on the corrected parameter. Thus, the process treatment in each cell is performed in a state in which the correction value is reflected.

The above-described series of steps will be described with reference to fig. 7 (a) as a specific example. In fig. 7 (a), 3 sets G10 to G30 are shown. The group G10 is composed of COT11, COT12, and PAB11 to PAB 13. The group G20 is composed of COT21, COT22, and PAB21 to PAB 23. The group G30 is composed of COT31, COT32, and PAB31 to PAB 33. Fig. 7 (a) shows the cell variation in film thickness of each cell included in each set. The value R1 indicated by a broken line for each cell in the set G10 represents an average value of the film thicknesses of the wafers W processed in the set G10. FIG. 7 (a) shows the case where the average thickness of the wafers W in the set G10 is 90.05 nm.

The thickness of COT11 was 89.73 nm. This indicates that, when the wafer W was processed in COT11, the resist film after the heat treatment was reduced to about 0.32nm (-0.32 nm) from the target value of 90.05 μm, and COT11 affected the change in film thickness. The thickness of the PAB11 film was 90.13 nm. This indicates that when the wafer W was processed by the PAB11, the resist film after the heat treatment was increased by about 0.08nm (+ 0.08nm) from the target value of 90.05nm, and the PAB11 affected the change in film thickness. As described above, it is understood that the process treatment in each cell before the correction affects the change in the film thickness of the resist film after the heat treatment. The cell deviation for film thickness was-0.32 nm in the case of COT11 and +0.08nm in the case of PAB 11. Therefore, wafers W that passed through COT11 and PAB11 had a film thickness variation of-0.32 nm +0.08nm to-0.24 nm from the collective target value (average value of film thicknesses of wafers W) under the influence of the film thickness variation corresponding to the cell deviation of 2 cells.

As described above, the correction value calculation unit 102 sets the set target value for each set based on the result held in the inspection result holding unit 101. Then, the correction value calculation unit 102 calculates a unit deviation (a first unit deviation and a second unit deviation) with respect to a film thickness change in the process performed in each unit based on the difference from the collective target value. The collective target value may be set to a value different from the average value of the film thicknesses of the wafers W.

If the cell deviation with respect to the film thickness can be calculated for each cell group, the correction value can be made a value based on the cell deviation. That is, in the case of COT11, since the cell deviation with respect to the film thickness change is-0.32 nm, the correction value of the parameter for realizing the process in which the film thickness becomes + 0.32nm may be calculated. In the case of PAB11, the cell deviation with respect to the film thickness change was +0.08nm, and therefore, the correction value of the parameter for realizing the process for the film thickness of-0.08 nm could be calculated.

Further, regarding the calculation of the regression coefficient described in step S02, the detailed flow can be changed in consideration of the degree of safety or the ease of correction corresponding to the correction of the parameter to be corrected, from the inspection result held in the inspection result holding unit 101. That is, it is possible to set a priority for minimizing the norm (norm minimizing priority), and change a detailed flow for calculating the correction value in consideration of the priority. In fig. 8, a flow of calculating the correction value in consideration of the norm minimization priority is shown.

First, the regression coefficient calculation unit 103 executes step S11. In step S11, a determination is made as to whether or not the cell deviation can be calculated by the least square method (least square method with equality constraint) using the result held in the inspection result holding unit 10. Then, when the result of this determination is "YES", the regression coefficient calculation unit 103 executes step S12. In step S12, the cell deviation (first cell deviation, second cell deviation) of each cell is calculated using the least square method with the equation constraint.

As described above, when the inspection result of the film thickness corresponding to the combination of all the cells through which the wafer W can pass in the same set exists, the cell deviation of all the cells can be determined by using the least square method with the equation constraint. For example, fig. 9 (a) shows an example of a set of 4 coating units U1, which are COT1 to COT4, and 4 heat treatment units U2, which are PAB1 to PAB 4. In the set shown in fig. 9 (a), when inspection results of the film thicknesses of the resist films in all combinations can be obtained, as shown in fig. 9 (b), the cell deviation of each cell can be calculated using the least square method with the equation constraint. That is, the overall average (average value of film thicknesses in a set) and the cell deviation (value corresponding to the difference) of the film thickness of the resist film per cell from the overall average can be calculated by the least square method with the equation constraint. In the above, the case where the inspection results of the film thicknesses of the resist films in all combinations can be obtained has been described, but whether the cell deviation can be actually calculated using the least square method with the equality constraint corresponds to the case where the obtained results are divided into subsets. Therefore, in step S11, a determination is made as to whether the obtained result is divided into subsets. In the case where the determination result in step S11 is yes, in step S12, the cell deviation and the correction value are calculated using the least square method with the equality constraint.

Next, if the result of the determination in step S11 is "NO (NO)", that is, if the inspection results do not sufficiently match and the cell deviation cannot be calculated by the least square method with the equation constraint, the regression coefficient calculation unit 103 executes step S13. In step S13, it is determined whether or not there is a norm minimization priority (the norm minimization priority differs for each element) when calculating the cell deviation and the correction value for each element (cell group). If the result of this determination is yes, that is, if there is a norm minimization priority in calculating the cell deviation and the correction value for each element (the norm minimization priorities for each element are different), the regression coefficient calculation unit 103 executes step S14. In step S14, the norm is minimized with respect to the set target value and the unit deviation is calculated in order of minimizing the priority based on the norm of each element. On the other hand, in the case where the result of this determination is "no", that is, in the case where there is no norm minimization priority (the norm minimization priorities for each element are the same) at the time of calculating the cell deviation and the correction value for each element, the regression coefficient calculation unit 103 executes step S15. In step S15, the cell deviation of each cell is calculated so that the norm of the entire elements other than the intercept becomes minimum.

As described above, fig. 8 illustrates a flow of changing the calculation method based on whether the unit deviation can be calculated using the least square method with the equality constraint and whether there is a norm minimization priority for each element. However, the calculations (steps S12, S14, S15) under the respective conditions shown in fig. 8 can also be concentrated on step S14. That is, the cell deviation may be calculated by executing only step S14 without executing steps S11 and S13. For example, as shown in step S12, the least squares solution with the equality constraint can be used, which means that the solution has no degrees of freedom. In this case, the same solution can be calculated regardless of whether or not there is the norm minimization priority, and therefore, the solution can be obtained even if the algorithm corresponding to step S14 is executed with the norm minimization priority set appropriately. Further, when considering a case where the norm minimization priority in step S14 is the same for each element, step S15 can be solved by the same algorithm as step S14. Therefore, the same solution as that in the case where the calculation is performed based on the flow of fig. 8 can be obtained even if only step S14 is executed.

Referring to fig. 10 to 12, step S13 to step S15 will be described. Fig. 10 (a) shows the results of the examination of the set of 5 coating units U1, COT1 to COT5, and 5 heat treatment units U2, PAB1 to PAB 5. In the example shown in fig. 10 (a), inspection results of the film thicknesses of the resist films in all combinations are not obtained. That is, fig. 10 shows a state in which Set1, which is the inspection result of the combination of COT1, COT2, COT3, PAB1, and PAB2, and Set2, which is the inspection result of the combination of COT4, COT5, PAB3, PAB4, and PAB5, are obtained. In this state, as shown in fig. 10 (b), the ensemble average (corresponding to the Set target value), the difference between the ensemble average and the average value of each of the Set1 and 2, and the cell deviation of each cell from the Set target value by the least square method in each of the Set1 and 2 can be calculated. However, the cell deviation of each cell is Set unit where the inspection result is obtained. Therefore, the correction value based on the cell deviation is a correction value for correcting the average value in Set units, and is not a correction value corresponding to correction in Set units. In the state shown in fig. 10 (a), when it is desired to calculate the cell deviation of each cell from the ensemble average of the set by the least square method, the number of solutions is infinite because the equation is insufficient for the unknowns. That is, the cell deviation of the process treatment in each cell cannot be calculated.

When there are situations where an infinite number of solutions exist using the least squares with equality constraints, in general, the solution in which the norm of the explanatory variable becomes minimum is selected. Here, the ensemble average (intercept) and each unit deviation are explanatory variables. Fig. 11 shows the result of calculating the unit deviation of each unit so that the norm of each unit deviation except the expected value (intercept) of the average film thickness in the set becomes the minimum, based on the inspection result shown in fig. 10 (a). In this case, as shown in FIG. 11, the norm of COT/PAB is 1.572, and the cell deviations of COT 1-5 and PAB 1-5 are 1.278 and 0.915, respectively. The process (calculation) of determining the solution under the condition that the norm becomes minimum may correspond to step S15 shown in fig. 8. As a specific flow of the process of determining the solution under the condition that the norm becomes minimum, a known method can be used.

However, in the result shown in fig. 11, the norm other than the intercept of the entire plurality of cells is minimized, but the priority of correction of the parameter corresponding to the cell is not considered. In the case where the norm reduction is desired for the heating temperature of the heat processing unit U2 as described above, the process of minimizing the norm is performed so that the correction value of the heating temperature of the heat processing unit U2, which is the portion where the parameter of the correction value is desired to be reduced, becomes small. In the case of the present embodiment, the processing of calculating the cell deviation is performed with respect to the heating temperature of the heat treatment cell U2 so that the norm becomes minimum.

As described above, when the norm minimization priorities in the calculation of the cell deviation (calculation of the correction value) are different for the parameters of the respective cells, the cell deviation of each cell for minimizing the norm is calculated from the parameter having the higher norm minimization priority. In the case of the present embodiment, the parameters of each unit are two kinds of parameters, i.e., the rotation speed of the coating unit U1 and the heating temperature of the heat treatment unit U2. The parameter having a higher norm minimization priority corresponds to a parameter for which it is not desirable to increase the correction value more than necessary. The parameter (element) for increasing the correction value to a value larger than necessary may not be increased, and examples thereof include a parameter that is not easily corrected, a parameter that causes some risk by correction, and the like. On the other hand, examples of the parameter with which the correction value can be changed to a large value include a parameter with which correction is easy and a parameter with which the risk of correction is small. As described above, when there is a parameter for which the correction value is to be made as small as possible, the processing is performed with the norm minimization priority of the element (cell group) to which the parameter belongs being set high. Then, when the norm is minimized, the minimization is calculated according to the factor with high priority of norm minimization. In the configuration of the present embodiment, PAB having the heating temperature as a parameter is an element having a higher norm minimization priority than COT having the rotation speed as a parameter. Therefore, an element having a high priority for norm minimization, that is, a unit deviation of process treatment for each unit for minimizing the norm according to the PAB is calculated.

The calculation of the cell deviation (calculation corresponding to step S14 in fig. 8) in consideration of the norm minimization priority can be performed by the following method, for example. That is, an equation constraint and an objective function are described that take the expected value of the average film thickness in a certain set, the unit deviation of the film thickness in each unit, as explanatory variables (regression coefficients). Then, an additional objective function considering the norm minimization priority is added, and a regression coefficient is calculated by solving a multi-objective optimization problem. Thus, the unit deviation can be calculated so as to minimize the norm, taking into consideration the norm minimization priority for each unit. The calculation of the regression coefficient itself can use a known method.

The results of calculating the cell deviation for each cell according to the above-described flow are given in fig. 12. In the results shown in fig. 12, the square error is the same as that in the results shown in fig. 11, but the cell deviations COT1 to COT5 become large, and the cell deviations PAB1 to PAB5 become small. Specifically, in the results shown in fig. 12, the norm of the coating unit U1(COT1 to COT5) was 1.681, while the norm of the heat treatment unit U2(PAB1 to PAB5) was 0.663.

When the unit deviation of the process of each unit is calculated so that the norms are sequentially minimized by the elements having higher norms minimization priority, the norm of the entire unit is not the minimum. For example, the COT/PAB norm becomes 1.572 in the calculation result shown in FIG. 11, whereas the COT/PAB norm becomes 1.807 in the calculation result shown in FIG. 12. However, the process of the cell of the element having the highest norm minimization priority can be calculated to have a small cell deviation. That is, the norm can be reduced for the cell variation of the process treatment relating to the parameter with high norm minimization priority. This is because the unit deviation of the high-priority element calculated so as to minimize the norm becomes further smaller.

Whether or not the norm minimization priority is set can be controlled by the correction value calculation unit 102 of the control device 100. When step S13 is executed, a method of making a determination based on information held by the present apparatus can be employed.

In the present embodiment, a case has been described in which the cell deviation (the first cell deviation, the second cell deviation) is calculated and corrected for the process processing based on 2 parameters in 2 processing cells. The 2 treatment units are a coating unit U1 and a heat treatment unit U2, and the 2 parameters are the rotation speed and the heating temperature. However, the above-described flow can be performed in the same flow even when the number of processing units is 3 or more and the number of types of parameters is increased to 3 or more. That is, when 3 types of processing units (i.e., 3 types of process processing) have a norm minimization priority of 3, the processing for calculating the unit deviation whose norm becomes the minimum is repeated in the same manner as described above, in order from the processing unit having the highest norm minimization priority. Thus, 3 kinds of cell deviations among 3 kinds of cells subjected to 3 processes can be calculated in consideration of the priorities. When the types of the processing units and the parameters are 4 or more, the unit deviation can be calculated in the same flow with priority taken into consideration. Further, the norm minimization priority may be set only in a part of the processing units (a part of the process).

The substrate processing control method can be performed at a predetermined time when the substrate processing using the substrate processing system 1 is performed. For example, the processing may be performed at a time designated by the user. When the process is completed for any batch of substrates, the above-described process can be performed without departing from the preset range in a simple average of the film thicknesses of the substrates processed in the respective units with reference to the film thicknesses of the closest predetermined number of substrates in the batch. In this case, the correction amount in each unit may be calculated from the above-described simple average.

Further, the start of the above-described processing may be determined based on the result of comparison between the 95% confidence interval and the reference value. Specifically, when the processing is completed for a given batch of substrates, the 95% confidence interval of the estimated value is calculated when the cell deviation among the cells is estimated from the measurement results of the film thicknesses of the predetermined number of substrates closest to the given batch. When the 95% confidence interval does not include a value that becomes a reference of the estimated value, it may be determined that the above-described processing is performed. For example, when the collective target value is equal to the current expected value of the average film thickness, the 95% confidence interval of the cell deviation in the coating unit U1 or the heat treatment unit U2 may not include the reference value 0, and this may be used as a trigger (trigger) for starting the substrate treatment control method described above. In addition, when the collective target value is set to be different from the expected value of the average film thickness, it may be assumed that, for example, only the first unit is involved in correction of the average film thickness. Based on this assumption, a case where the 95% confidence interval of the sum of the expected film thickness average value and the first unit deviation does not include the collective target value as the reference value may be used as the cause. In this case, a case where the 95% confidence interval of the second cell deviation does not include the reference value 0 may be used as the cause. The above method is merely an example, and is not limited thereto.

[ Effect ]

According to the substrate processing control method and the substrate processing apparatus of the above embodiments, a data set including information identifying the first level cell (coating cell U1) on which the first process was performed, information identifying the second level cell (heat treatment cell U2) on which the second process was performed, and information on the characteristic amount (for example, film thickness) of the substrate is acquired from the processed plurality of substrates. In the calculating step, information including an expected value of the feature amount, a level cell deviation of a first level cell from the expected value, and a level cell deviation of a second level cell from the expected value is calculated. Further, the first parameter in the first unit or the second parameter in the second unit is corrected based on the calculated information. With this configuration, the leveling cell deviation can be calculated for each of the plurality of first processing leveling cells and the plurality of second processing leveling cells, and the parameter of each of the plurality of first processing leveling cells and the plurality of second processing leveling cells can be corrected based on the leveling cell deviation. Therefore, even for a substrate that has been processed in a plurality of leveling cells, such as a plurality of types of processing cells, correction can be appropriately performed for each cell with respect to a target value using a data set including feature amounts of the substrate.

Conventionally, a method of correcting a characteristic amount of a characteristic of a substrate after processing in a state where the characteristic amount is different from a target value has been studied. However, there has been no study on a method of appropriately controlling the degree of correction of the parameter of the unit on which the process is performed, based on the characteristic amount of the substrate after the plurality of types of processes are repeated. In particular, there has been no study on a method of calculating a correction value for correcting a characteristic amount of a substrate in consideration of which processing unit changes the characteristic amount to which degree when a plurality of types of processing units are provided. In contrast, according to the substrate processing control method and the substrate processing apparatus described above, the level cell deviation is calculated for each of the first level cell and the second level cell, and the parameter of each cell is corrected based on the result. Therefore, even for a substrate that has been processed in a plurality of leveling cells, such as a plurality of types of processing cells, correction can be appropriately performed for each cell with respect to a target value using a data set including feature amounts of the substrate.

In the above-described embodiment, when the first level cell deviation in the first level cell and the second level cell deviation in the second level cell are calculated, the level cell deviation is calculated so that the norm other than the expected value of the characteristic amount becomes minimum. By adopting the above-described configuration, for example, even when only a data set in which the range of cell deviation cannot be calculated for each cell by a conventional method such as the least square method is obtained, the first level cell deviation (first cell deviation) and the second level cell deviation (second cell deviation) can be calculated. Therefore, according to the above configuration, correction can be appropriately performed for each cell with respect to the target value. In particular, even in a state where the data set is insufficient, the cell deviation of each cell can be appropriately calculated from the viewpoint of minimizing the norm, and therefore, more appropriate correction can be performed.

In the above-described embodiment, when the norm minimization priority corresponding to the order in which the processing for reducing the correction value is prioritized is determined in advance, the unit deviation is calculated in order from the element having the highest norm minimization priority so that the norm other than the expected value of the feature value becomes the minimum. With this configuration, it is possible to prevent the element having a high norm minimization priority from being corrected to include a cell deviation derived from another element. Therefore, the correction value can be reduced for the element having the higher norm minimization priority. In the above embodiment, the heating temperature of the heat treatment unit U2 corresponding to the second parameter is a parameter belonging to an element having a high norm minimization priority. Therefore, the correction value of the heating temperature can be reduced by calculating the correction value from the heat treatment unit U2 so as to minimize the norm of the cell deviation.

In addition, as in the above-described embodiment, the plurality of first processing units and the plurality of second processing units can be divided into sets in which processing units capable of processing one substrate are integrated with each other. In this case, an aggregate target value is set for each aggregate in which processing units capable of processing one substrate are integrated with each other, and a first unit deviation and a second unit deviation are calculated. Thus, the cell shift can be calculated with higher accuracy than a configuration in which the cell shift is calculated by considering a combination of the processing cells that cannot process one substrate. When the cell shift is calculated without taking into consideration the set, for example, it is considered that the substrate processing using the first processing unit and the second processing unit included in the sets different from each other is performed, and the cell shift can be calculated. In such a case, the calculation accuracy of the cell deviation may be reduced. In contrast, as described above, the cell deviation is calculated for each set, so that the cell deviation can be calculated with high accuracy.

[ other embodiments ]

Although various exemplary embodiments have been described above, the present invention is not limited to the above exemplary embodiments, and various omissions, substitutions, and changes may be made. Further, elements in different embodiments may be combined to form another embodiment.

For example, in the above-described embodiment, the case where 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 process module 12 has been described. However, the substrate processing control method described above can also be applied to a process different from the formation of the resist film on the substrate. For example, in the coating and developing apparatus 2, the lower layer film and the upper layer film are also formed, and the above-described process may be controlled by the control apparatus 100 while correcting the parameters. In the substrate processing process not described in the above embodiment, the parameter correction by the control device 100 may be applied. As described above, the calculation of the cell deviation and the correction of the parameter based on the cell deviation in the processing described in the above embodiment are not particularly limited.

In addition, the characteristic amount is not limited to the film thickness of the film formed on the substrate. As the characteristic amount, for example, a line width of the resist pattern or the like can be used. Further, the parameters of the first processing and the parameters of the second processing can also be changed as appropriate in accordance with the feature amount. For example, in the above embodiment, the rotation speed in the coating unit U1 that coats the processing liquid is used as the parameter, but the rotation speed may be selected as the parameter for another processing unit that performs processing while rotating the substrate. Further, in the case where some processes using the processing liquid are performed, the characteristics of the processing liquid may be selected as parameters. Further, one of the processing conditions in the processing unit may also be selected as a parameter. As described above, the feature amount of the characteristic of the substrate can be appropriately selected, and the first process and the second process can be appropriately selected according to the feature amount. Further, the first parameter in the first processing and the second parameter in the second processing can also be changed appropriately based on the feature amount and the like.

In the above-described embodiment, the flow of calculating the correction value of the parameter for each cell after calculating the regression coefficient is described as shown in fig. 6, but the flow may be changed.

When the control device 100 calculates the correction value, all the steps shown in fig. 8 are not performed. For example, if only the data set of the portion in which the cell deviation cannot be calculated by the least square method is obtained and the priority of each element is determined to exist, step S11 and step S13 may be omitted. As described above, when the number or content of the data sets obtained by the control device 100, the characteristics of the parameters of the processing units that are the objects of calculating the unit deviation and the correction value, and the like are known in advance, the processing can be appropriately omitted based on the content grasped by the device.

In the above-described embodiment, the case where the expected value of the average film thickness, the first cell deviation, and the second cell deviation are individually processed in consideration of the norm minimization priority and in calculation of the correction value for further reducing the cell deviation has been described. However, a part of the 3 elements may be integrated into one to be processed. Specifically, it is considered that the expected value of the average film thickness described in the above embodiment and the first cell deviation (cell deviation of the coating cell U1) are integrally processed. In this case, a value obtained by combining the first cell deviation and the expected value of the average film thickness (intercept) is treated as the expected value of the film thickness of the first cell, the objective function is described by the expected value of the film thickness of the first cell and the second cell deviation, and the optimal solution of the regression coefficient is calculated. The average value of the expected values of the film thickness of the first cell does not become 0, but the same effect as the norm minimization of the first cell deviation can be obtained by replacing the norm minimization with the distribution minimization.

From the above description, various embodiments of the present invention have been described in the present specification for illustrative purposes, and it is to be understood that various changes can be made without departing from the scope and spirit of the present invention. Accordingly, the various embodiments disclosed in this specification are not to be taken in a limiting sense, and the true scope and spirit are to be given the scope of the appended claims.