KR102452019B1 - Substrate processing apparatus, temperature control method, and temperature control program - Google Patents

Abstract

An object of the present invention is to control the temperature of the heater in each divided region so that the critical dimension of the measurement point of the substrate satisfies a predetermined condition.
The mounting table is provided with a mounting surface for arranging one or both of a substrate and a ring member disposed so as to surround the substrate, and a heater capable of adjusting the temperature is provided in each divided region into which the mounting surface is divided. The calculation unit uses, as a parameter, a critical dimension at a predetermined measurement point of the substrate when predetermined substrate processing is performed on the substrate disposed on the arrangement surface, and the temperature of the heater in each divided region, and the measurement point and the divided region including the measurement point Using a predictive model that predicts by adding the influence of the temperature of the heaters of other divided regions according to the distance between the other divided regions, the target temperature of the heater of each divided region where the critical dimension of the measurement point satisfies a predetermined condition is determined. Calculate. The heater control unit controls so that the heater of each divided region becomes the target temperature calculated by the calculation unit when performing substrate processing on the substrate disposed on the arrangement surface.

Description

Substrate processing apparatus, temperature control method and temperature control program {SUBSTRATE PROCESSING APPARATUS, TEMPERATURE CONTROL METHOD, AND TEMPERATURE CONTROL PROGRAM}

Various aspects and embodiments of the present invention relate to a substrate processing apparatus, a temperature control method, and a temperature control program.

As the generation of semiconductor technology progresses, the diameter of a substrate such as a wafer is increasing. On the other hand, transistors tend to be miniaturized. For this reason, higher precision is calculated|required by a board|substrate process.

One of the precision related to substrate processing is the uniformity of critical dimensions within the substrate. In substrate processing, the progress of processing changes according to the temperature of the substrate. Therefore, in the substrate processing apparatus, in order to more highly control the temperature of the substrate, the placement surface for arranging the substrate on the placement table is divided into a plurality of divided regions, and a heater is installed in each of the divided regions to provide a predetermined position of the substrate. One is to adjust the temperature of each partitioned region so that the critical dimension of α satisfies a predetermined condition. For example, based on a matrix describing the relationship between the control parameter of each divided region of the arrangement surface and the expected temperature at a predetermined position of the substrate, the set value of the heater for each divided region is obtained (eg, Patent Document 1 below) Reference).

Japanese Patent Laid-Open No. 2016-178316

By the way, when the mounting surface of the mounting table is divided into a plurality of divided regions and the temperature of each divided region is adjusted, the temperature in the vicinity of the boundary between each divided region and the adjacent divided regions is affected by the adjacent divided regions and the temperature changes. For this reason, in the prior art, the temperature in the vicinity of the boundary of each divided area with the adjacent divided area does not become the expected temperature, and it may not be possible to control so that the critical dimension in the vicinity of the boundary satisfies a predetermined condition. As a result, in the prior art, it is not possible to precisely control the uniformity of the critical dimension in the substrate.

Moreover, in the substrate processing apparatus, a heater may be provided also in the peripheral area|region of a board|substrate. In the case of such a configuration, the substrate processing apparatus may not be able to control the critical dimension to satisfy a predetermined condition in the vicinity of the outer edge of the substrate due to the influence of the heater in the peripheral region.

In one embodiment, the disclosed substrate processing apparatus includes a mounting table, a calculation unit, and a heater control unit. The mounting table is provided with a mounting surface for arranging one or both of a substrate and a ring member disposed so as to surround the substrate, and a heater capable of adjusting the temperature is provided in each divided region into which the mounting surface is divided. The calculation unit uses, as a parameter, a critical dimension at a predetermined measurement point of the substrate when predetermined substrate processing is performed on the substrate disposed on the arrangement surface, and the temperature of the heater in each divided region, and the measurement point and the divided region including the measurement point Using a predictive model that predicts by adding the influence of the temperature of the heaters of other divided regions according to the distance between the other divided regions, the target temperature of the heater of each divided region where the critical dimension of the measurement point satisfies a predetermined condition is determined. Calculate. The heater control unit controls so that the heater of each divided region becomes the target temperature calculated by the calculation unit when performing substrate processing on the substrate disposed on the arrangement surface.

According to one aspect of the disclosed substrate processing apparatus, there is an effect that the temperature of the heater in each divided region can be controlled so that the critical dimension of the measurement point of the substrate satisfies a predetermined condition.

1 is a schematic configuration diagram of a substrate processing system according to an embodiment.
2 is a diagram schematically illustrating a substrate processing apparatus according to an embodiment.
3 is a plan view showing a mounting table according to an embodiment.
4 is a block diagram illustrating a schematic configuration of a control unit for controlling a substrate processing apparatus according to an exemplary embodiment.
It is a figure which shows an example of a temperature distribution.
6 is a diagram for explaining the relationship between divided regions.
It is a figure explaining an example of the relationship between the sum of squares of an error, and a range.
8 is a flowchart showing an example of the flow of the temperature control method according to the first embodiment.
9 is a flowchart showing an example of the flow of the temperature control method according to the second embodiment.
10 is a diagram schematically showing a substrate processing apparatus according to a third embodiment.
11 is a plan view showing a first mounting table and a second mounting table according to a third embodiment.
12 is a block diagram showing a schematic configuration of a control unit that controls the substrate processing apparatus according to the fourth embodiment.
13 is a diagram schematically showing the maximum and minimum points of CDs on the wafer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a substrate processing apparatus, a temperature control method, and a temperature control program disclosed by the present application will be described in detail with reference to the drawings. In addition, in each figure, the same code|symbol shall be attached|subjected about the same or corresponding part. In addition, the invention disclosed by this embodiment is not limited. Each embodiment can be appropriately combined within a range that does not contradict the processing content.

(First embodiment)

[Configuration of substrate processing system]

First, the schematic structure of the substrate processing system which concerns on embodiment is demonstrated. A substrate processing system is a system which performs predetermined substrate processing with respect to substrates, such as a wafer. In this embodiment, the case where plasma etching is performed as a substrate processing with respect to a board|substrate is demonstrated as an example. 1 is a schematic configuration diagram of a substrate processing system according to an embodiment. The substrate processing system 1 includes a substrate processing apparatus 10 and a measurement apparatus 11 . The substrate processing apparatus 10 and the measurement apparatus 11 are communicatively connected to each other through the network N. Any type of communication network, such as a LAN (Local Area Network) or a VPN (Virtual Private Network), can be employed for the network N, whether wired or wireless.

The substrate processing apparatus 10 is an apparatus that performs predetermined substrate processing on a substrate. In the present embodiment, the substrate processing apparatus 10 performs plasma etching on a semiconductor wafer (hereinafter, referred to as a “wafer”) as a substrate.

The measurement apparatus 11 is an apparatus for measuring a critical dimension at the measurement point by using a predetermined position of the substrate on which the substrate processing has been performed by the substrate processing apparatus 10 as a measurement point. In the present embodiment, the measurement device 11 measures the width of the pattern at the measurement point as a critical dimension. Hereinafter, the critical dimension is also referred to as "CD". A plurality of measurement points for measuring CD are provided at different positions on the wafer. The measuring device 11 measures the width of each pattern at each measurement point. The measurement device 11 may be an inspection device that inspects a defect of a substrate. The measurement apparatus 11 transmits the measured data of the CD of each measurement point to the substrate processing apparatus 10 .

In the substrate processing apparatus 10 , the placement surface on which the wafer is placed is divided into a plurality of divided regions, and based on the CD data of each measurement point received from the measurement device 11 , the CD of each measurement point of the wafer is pre-recorded. Control is performed to adjust the temperature of each divided region so as to satisfy a predetermined condition.

[Configuration of substrate processing apparatus]

Next, the structure of the substrate processing apparatus 10 is demonstrated. 2 is a diagram schematically illustrating a substrate processing apparatus according to an embodiment. 2 schematically shows a structure of a longitudinal cross-section of a substrate processing apparatus 10 according to an exemplary embodiment. The substrate processing apparatus 10 shown in FIG. 2 is a capacitively coupled parallel plate plasma etching apparatus. The substrate processing apparatus 10 includes a substantially cylindrical processing vessel 12 . The processing vessel 12 is made of, for example, aluminum. In addition, the surface of the processing container 12 is anodized.

In the processing container 12 , a mounting table 16 is provided. The mounting table 16 includes a support member 18 and a base 20 . The upper surface of the support member 18 serves as an arrangement surface on which a substrate to be subjected to substrate processing is disposed. In the present embodiment, the wafer W to be subjected to plasma etching is disposed on the upper surface of the support member 18 . The base 20 has a substantially disk shape, and its main part is made of, for example, a conductive metal such as aluminum. This base 20 constitutes a lower electrode. The base 20 is supported by a support 14 . The support 14 is a cylindrical member extending from the bottom of the processing vessel 12 .

A first high frequency power supply HFS is electrically connected to the base 20 via a matching unit MU1 . The first high-frequency power supply HFS is a power supply that generates high-frequency power for plasma generation, and generates high-frequency power at a frequency of 27 to 100 MHz, in one example, 40 MHz. The matching device MU1 has a circuit for matching the output impedance of the first high frequency power supply HFS with the input impedance of the load side (base 20 side).

Further, a second high frequency power supply LFS is electrically connected to the base 20 via a matching unit MU2. The second high frequency power supply LFS generates high frequency power (high frequency bias power) for drawing ions into the wafer W, and supplies the high frequency bias power to the base 20 . The frequency of the high frequency bias power is a frequency within the range of 400 kHz to 13.56 MHz, and is 3 MHz in one example. The matching device MU2 has a circuit for matching the output impedance of the second high frequency power supply LFS with the input impedance of the load side (base 20 side).

A support member 18 is provided on the base 20 . In one embodiment, the support member 18 is an electrostatic chuck. The support member 18 adsorbs the wafer W by an electrostatic force such as a Coulomb force, and holds the wafer W. The support member 18 has an electrode E1 for electrostatic absorption in a ceramic body portion. A DC power supply 22 is electrically connected to the electrode E1 via a switch SW1.

A ring member is disposed on the upper surface of the base 20 and around the support member 18 so as to surround the wafer W. For example, a focus ring FR is provided as a ring member on the upper surface of the base 20 and around the support member 18 . The focus ring FR is provided in order to improve the uniformity of plasma processing. The focus ring FR is made of a material appropriately selected according to the plasma treatment to be performed, and may be made of, for example, silicon or quartz.

A refrigerant passage 24 is formed inside the base 20 . A refrigerant is supplied to the refrigerant passage 24 from a chiller unit provided outside the processing container 12 through a pipe 26a. The refrigerant supplied to the refrigerant passage 24 is returned to the chiller unit through the pipe 26b. In addition, the detail of the mounting table 16 including this base 20 and the support member 18 is mentioned later.

An upper electrode 30 is provided in the processing container 12 . The upper electrode 30 is disposed above the mounting table 16 to face the base 20 , and the base 20 and the upper electrode 30 are provided substantially parallel to each other.

The upper electrode 30 is supported on the upper portion of the processing vessel 12 through the insulating shield member 32 . The upper electrode 30 may include an electrode plate 34 and an electrode support 36 . The electrode plate 34 faces the processing space S, and provides a plurality of gas discharge holes 34a. The electrode plate 34 may be formed of a low-resistance conductor or semiconductor having low Joule heat.

The electrode support 36 detachably supports the electrode plate 34 and may be made of, for example, a conductive material such as aluminum. The electrode support 36 may have a water cooling structure. A gas diffusion chamber 36a is provided inside the electrode support body 36 . In the gas diffusion chamber 36a, a plurality of gas flow holes 36b communicating with the gas discharge holes 34a extend downward. In addition, a gas inlet 36c for introducing a process gas to the gas diffusion chamber 36a is formed in the electrode support 36 , and a gas supply pipe 38 is connected to the gas inlet 36c.

A gas source group 40 is connected to the gas supply pipe 38 via a valve group 42 and a flow rate controller group 44 . The valve group 42 has a plurality of on-off valves, and the flow controller group 44 has a plurality of flow controllers called mass flow controllers. In addition, the gas source group 40 has a plurality of types of gas sources required for plasma processing. A plurality of gas sources of the gas source group 40 are connected to the gas supply pipe 38 via a corresponding on/off valve and a corresponding mass flow controller.

In the substrate processing apparatus 10 , one or more gases from one or more gas sources selected from a plurality of gas sources of the gas source group 40 are supplied to the gas supply pipe 38 . The gas supplied to the gas supply pipe 38 reaches the gas diffusion chamber 36a and is discharged to the processing space S through the gas flow hole 36b and the gas discharge hole 34a.

In addition, as shown in FIG. 2 , the substrate processing apparatus 10 may further include a ground conductor 12a. The grounding conductor 12a is a substantially cylindrical grounding conductor, and is provided so as to extend upward from the sidewall of the processing container 12 at a height of the upper electrode 30 .

In addition, in the substrate processing apparatus 10 , the deposition shield 46 is detachably provided along the inner wall of the processing container 12 . In addition, the deposition shield 46 is also provided on the outer periphery of the support part 14 . The deposition shield 46 prevents etching by-products (depositions) from adhering to the processing container 12 , and can be configured by coating an aluminum material with ceramics such as Y2O3.

On the bottom side of the processing vessel 12 , an exhaust plate 48 is provided between the support 14 and the inner wall of the processing vessel 12 . The exhaust plate 48 can be constituted, for example, by coating an aluminum material with ceramics such as Y2O3. An exhaust port 12e is provided in the processing container 12 below the exhaust plate 48 . An exhaust device 50 is connected to the exhaust port 12e via an exhaust pipe 52 . The exhaust device 50 includes a vacuum pump such as a turbo molecular pump, so that the inside of the processing vessel 12 can be depressurized to a desired degree of vacuum. In addition, an inlet/outlet 12g for wafers W is provided on the sidewall of the processing container 12 , and the inlet/outlet 12g is opened and closed by a gate valve 54 .

The operation of the substrate processing apparatus 10 configured as described above is collectively controlled by the control unit 100 . The control unit 100 is, for example, a computer, and controls each unit of the substrate processing apparatus 10 . The operation of the substrate processing apparatus 10 is collectively controlled by the control unit 100 .

[Configuration of the bench]

Next, the mounting table 16 will be described in detail. 3 is a plan view showing a mounting table according to an embodiment. As described above, the mount 16 has a support member 18 and a base 20 . The support member 18 has a body portion 18m made of ceramic. The main body 18m has a substantially disk shape. The body portion 18m provides an arrangement region 18a and an outer peripheral region 18b. The arrangement area 18a is a substantially circular area in plan view. On the upper surface of this arrangement area 18a, a wafer W is placed. In addition, the diameter of the arrangement area|region 18a is substantially the same diameter as the wafer W, or is made slightly smaller than the diameter of the wafer W. As shown in FIG. The outer peripheral region 18b is a region surrounding the arrangement region 18a, and extends substantially in an annular shape. In one embodiment, the upper surface of the outer peripheral region 18b is at a lower position than the upper surface of the arrangement region 18a.

As mentioned above, in one embodiment, the support member 18 is an electrostatic chuck. The support member 18 of this embodiment has the electrode E1 for electrostatic absorption in the arrangement area|region 18a. This electrode E1 is connected to the DC power supply 22 via the switch SW1 as described above.

Moreover, several heaters HT are provided in the arrangement area|region 18a and below the electrode E1. In one Embodiment, the arrangement area|region 18a is divided|segmented into several division area|region, and the heater HT is provided in each division area. For example, as shown in FIG. 3 , a plurality of heaters HT are provided in the central circular region of the arrangement region 18a and in a plurality of concentric annular regions surrounding the circular region. Further, in each of the plurality of annular regions, the plurality of heaters HT are arranged in the circumferential direction. In addition, the division|segmentation method of the division|segmentation area shown in FIG. 3 is an example, and is not limited to this. The arrangement area 18a may be divided into more divided areas. For example, the arrangement region 18a may be divided into divided regions having a smaller angular width and narrower radial width as they are closer to the outer periphery. The heater HT is individually connected to the heater power supply HP shown in FIG. 2 via a wiring (not shown) provided on the outer periphery of the base 20 . Each heater HT is supplied with individually adjusted electric power from the heater power supply HP. Thereby, the heat|fever emitted by each heater HT is individually controlled, and the temperature of the several division area|region in the arrangement area|region 18a is adjusted individually. At least one measurement point for measuring the CD of the wafer W is provided in the divided area where the heater HT is installed.

[Configuration of control unit]

Next, the control unit 100 will be described in detail. 4 is a block diagram illustrating a schematic configuration of a control unit for controlling a substrate processing apparatus according to an exemplary embodiment. The control unit 100 includes a communication interface 101 , a process controller 102 , a user interface 103 , and a storage unit 104 .

The communication interface 101 enables communication with the measurement device 11 via the network N, and transmits/receives various data to and from the measurement device 11 . For example, the communication interface 101 receives data of the CD transmitted from the measurement device 11 .

The process controller 102 includes a CPU (Central Processing Unit) to control each unit of the substrate processing apparatus 10 .

The user interface 103 is configured with a keyboard through which a process manager inputs commands to manage the substrate processing apparatus 10 , a display that visualizes and displays the operation status of the substrate processing apparatus 10 , and the like.

The storage unit 104 stores a control program (software) for realizing various processes executed in the substrate processing apparatus 10 under the control of the process controller 102 , a recipe in which processing condition data, and the like are stored. In addition, recipes such as control programs and processing condition data are stored in computer-readable computer recording media (eg, hard disks, optical disks such as DVDs, flexible disks, semiconductor memories, etc.), or It is also possible to receive the transmission from the device at any time, for example through a dedicated line, and use it online.

The process controller 102 has an internal memory for storing programs and data, reads the control program stored in the storage unit 104, and executes the read control program processing. The process controller 102 functions as various processing units by operating the control program. For example, the process controller 102 has the functions of a generator 102a, a calculator 102b, a plasma controller 102c, and a heater controller 102d. In addition, in the substrate processing apparatus 10 according to the present embodiment, when the process controller 102 has the functions of the generator 102a , the calculator 102b , the plasma controller 102c , and the heater controller 102d is described as an example, but the functions of the generation unit 102a, the calculation unit 102b, the plasma control unit 102c, and the heater control unit 102d may be realized by distributing the functions to a plurality of controllers.

However, in substrate processing such as plasma etching, it is required that the CD range (difference between the maximum CD value and the CD minimum value) on the entire wafer W is small, and that the average CD value is close to the target value. . On the other hand, in the substrate processing, the progress of the processing changes according to the temperature of the wafer W. For example, in plasma etching, the etching progress speed changes according to the temperature of the wafer W. Therefore, in the substrate processing apparatus 10 according to the present embodiment, using a predictive model for predicting the critical dimension at a predetermined measurement point of the wafer W using the temperature of each heater HT as a parameter, the wafer ( In W), a situation in which the CD range on the entire surface is smaller and a situation in which the average value of the CD is close to the target value is realized.

Here, the predictive model will be described. In this embodiment, the predictive model which modeled the critical dimension of the measurement point by the linear function of the temperature of each heater HT is demonstrated.

In the vicinity of the boundary between each divided area and the adjacent divided area, the temperature is also changed by the influence of the adjacent divided area. When the influence of the temperature of the heater HT of the adjacent divided region on the measurement point is added, the temperature of each measurement point can be expressed by the following Equation (1) with the temperature T of the heater HT as a parameter.

Here, i is the number of the divided area in which the heater HT including the measurement point is installed. j is the number of measurement points included in the divided area where the heater HT is installed. T _i represents the temperature of the partitioned region of number i. δT _i,j represents the temperature difference between the temperature of the measurement point j in the divided region of number i and the temperature of T _i . This temperature difference is caused by the influence of heat from adjacent partitioned areas. δT _i,j also varies depending on the distance of the measurement point from the adjacent divided region.

δT _i,j is obtained as follows. In a state in which the temperature of the heaters HT of two adjacent divided regions is changed, the temperature distribution of the divided regions is measured by infrared thermography. What is necessary is just to obtain|require the temperature distribution of a division area|region in advance at least once. In addition, it is not necessary to measure the temperature distribution of a divided area|region using the substrate processing apparatus 10, You may measure using the mounting table for measurement made into the same structure as the mounting table 16. For example, you may measure using the mounting table for measurement by the same component as the mounting table 16 . It is a figure which shows an example of a temperature distribution. In the mounting table 16 shown in FIG. 5 , the mounting area 18a on which the wafer W is placed is divided into divided areas 19a, 19b, 19c, and 19d. FIG. 5A shows an image of infrared thermography when the temperature of the heater HT is changed in the inner divided region 19a and the divided regions 19b, 19c, and 19d. FIG. 5B shows a graph showing the change in temperature with respect to the distance d from the boundary with the boundary of the divided regions 19a and 19b being zero. In the example of FIG.5B, the temperature of the divided area|region 19a is 29.5 degreeC, and the temperature of the divided areas 19b and 19c is 34 degreeC. As shown in Fig. 5(B) , the temperature in the vicinity of the boundary between the divided region 19b and the divided region 19a does not reach 34°C under the influence of the divided region 19a, and the divided region 19a The temperature also changes with the distance from

For example, two adjacent divided regions 19 are divided into a divided region 19-1 and a divided region 19-2, the temperature of the divided region 19-1 is T _1-1 , and the divided region ( When the temperature of 19-2) is T _2-1 , the temperature T at the position of the distance d from the boundary of the divided region 19-2 can be expressed by an approximate expression as in the following equation (2) .

Here, λ is an integer for approximating the graph of the change in temperature. For example, when approximating the graph of temperature change in FIG. 5B , λ becomes 7.2 mm.

Equation (1) can be expressed as Equation (3) below when δT _i,j is expressed by Equation (2).

Here, k is the number of the division area adjacent to the i-th division area. d _i,j,k is the distance from the k-th division area adjacent to the j-th measurement point of the i-th division area. Since the position of the measurement point is determined in advance, each of d _{i, j, and k} can be obtained in advance. λ _i,j,k is an integer representing the influence of the adjacent k-th divided region on the j-th measurement point of the i-th divided region. When the influences of adjacent divided regions are equal, λ _{i, j, and k} may all have the same value. For example, when the measurement result of FIG. 5B is used, λ _{i, j, k} are all 7.2 mm.

6 is a diagram for explaining the relationship between divided regions. In Fig. 6, divided regions 19l to 19t are shown. The divided areas 19l to 19o and 19s are adjacent to the divided area 19p. Moreover, the measurement point 21 is included in the divided area|region 19p. When the number of the divided area 19p is i, the number of the divided areas 19l to 19o and 19s is k. Further, d _{i, j, k} is the distance between the measurement point 21 and the divided regions 19l to 19o and 19s as indicated by arrows in Fig. 6 .

Next, in order to obtain data used for generating the predictive model, the substrate processing apparatus 10 controls each heater HT, divides the temperature of each divided region into several levels, and at each temperature, the wafer ( W) is replaced, and plasma etching actually performed for each wafer W is individually performed. For example, the substrate processing apparatus 10 controls each heater HT to three or more temperatures, exchanges the wafer W at each temperature, and actually performs plasma etching separately. As an example, the substrate processing apparatus 10 performs plasma etching on the wafer W by setting each heater HT to 50°C. In addition, the substrate processing apparatus 10 performs plasma etching on the wafer W by setting the respective heaters HT to 55°C. In addition, the substrate processing apparatus 10 performs plasma etching on the wafer W by setting the respective heaters HT to 45°C. In addition, when obtaining the data used for generation|generation of a predictive model, the temperature of each divided area does not necessarily need to be common in all the divided areas. That is, some divided regions may have different temperatures from other divided regions. For example, the temperature may be different in the divided area near the center of the arrangement area 18a and the divided area near the outer periphery of the arrangement area 18a.

Each wafer W subjected to plasma etching at each temperature is respectively conveyed to the measuring device 11 . The measuring device 11 measures the CD of each of the conveyed wafers W at a predetermined position as a measuring point. For example, the measurement device 11 measures the CD of each measurement point of each wafer W subjected to plasma etching by setting the respective heaters HT to three temperatures of 45°C, 50°C, and 55°C. The measurement apparatus 11 transmits the measured data of the CD of each measurement point to the substrate processing apparatus 10 .

In the case of predicting the CD of the measurement point as a linear function of the temperature T of each heater HT, the CD of each measurement point is calculated using the temperature T of the heater HT as a parameter, the following equation (4-1) can be expressed as

Here, i is the number of the divided area in which the heater HT including the measurement point is installed. For example, a sequential number i is assigned to the divided area in which the heater HT is installed. j is the number of measurement points included in the divided area where the heater HT is installed. For example, a sequential number j is given to a measurement point for each divided area in which the heater HT is provided. CD _i,j represents the CD value of the measurement point of number j included in the division area of number i. T _i represents the temperature of the partitioned region of number i. T _i,j represents the temperature of the measurement point of number j of the divided area of number i. A _{11_ i,j} is the coefficient of the linear function for obtaining the CD value of the measurement point of number j included in the division area of number i from the temperature (T _i,j ). T _{i_a} represents the average temperature of the temperatures of three or more divided regions of number i for which CDs were measured. For example, when CD is measured at three temperatures of 45°C, 50°C, and 55°C, _{Ti _a} becomes 50°C. T _{i,j _a} represents the average temperature of three or more temperatures at which the CD of the measurement point number j of the divided region number i is measured. A _{10_ i,j} represents the average value of the CD measured at three or more temperatures of the measurement point of number j included in the divided region of number i, respectively.

Equation (4-1) is expressed as Equation (4-2), temperature (τ _l ) is expressed as Equation (5-2) below, and a _i,j,l is expressed as Equation (5-3) below. ), it can be expressed as Equation (5-1) below.

Here, l is the number of the divided area in which the heater HT is installed. For example, when there are 20 divided regions in which the heater HT is provided, l=1 to 20.

When generating a predictive model, the substrate processing apparatus 10 controls each heater HT, divides the temperature of each divided region by a number level, exchanges the wafer W at each temperature, Plasma etching actually performed is separately performed. For example, the substrate processing apparatus 10 controls each heater HT to three or more temperatures, exchanges the wafers W at each temperature, and actually performs plasma etching separately. As an example, the substrate processing apparatus 10 performs a plasma etching process on the wafer W by setting the respective heaters HT to 50°C. In addition, the substrate processing apparatus 10 performs a plasma etching process on the wafer W by setting the respective heaters HT to 55°C. Moreover, the substrate processing apparatus 10 sets each heater HT to 45 degreeC, and performs the plasma etching process with respect to the wafer W.

Then, each wafer W subjected to plasma etching at each temperature is moved to the measurement device 11, and a predetermined position of the wafer W is used as a measurement point, and the CD of the measurement point is obtained by the measurement device 11 measure That is, the CD of each measurement point of each wafer W to which the plasma etching process was performed by setting each heater HT to three temperatures of 45 degreeC, 50 degreeC, and 55 degreeC is measured. The measurement apparatus 11 transmits the measured data of the CD of each measurement point to the substrate processing apparatus 10 .

The generation unit 102a generates a predictive model from the data of the received CD. For example, the generation unit 102a sets each heater HT received from the measurement device 11 at three temperatures of 45°C, 50°C, and 55°C to measure points of each wafer W subjected to the plasma etching process. Based on the CD data of , using the CD of each measurement point and the temperature of each heater HT, fitting is performed to obtain the value of the coefficient A _{11_ i,j} .

When the value of the coefficient (A _{11_ i,j} ) is obtained, the coefficient (a _i,j,l ) is obtained from the above-mentioned equation (5-3), and using the above-mentioned equation (5-1), the temperature ( CD _i,j can be calculated from τ _l ).

The generation unit 102a substitutes the value of the obtained coefficient (A _{11_ i,j} ) into Equation (5-3) to obtain the coefficient (a _i,j,l ), and as a predictive model, the obtained coefficient (a _{i, j,l} ) is substituted to generate Equation (5-1).

The calculation unit 102b calculates the target temperature of the heater HT in each divided region in which the CD of the measurement point satisfies a predetermined condition by using the prediction model generated by the generation unit 102a. For example, the calculator 102b calculates the heater HT temperature of each divided region at which the sum of squares of the error of the CD of each measurement point with respect to the target value μ is minimized, using the predictive model.

A method of calculating the temperature of the heater HT in each divided region in which the sum of squares of the error is minimized will be described in detail.

The above-mentioned formula (5-1) can be expressed as the following formula (6).

Here, m is a number identifying a measurement point. For example, when there are 400 measurement points, m ranges from 1 to 400. In Formula (5-1), a number is sequentially assigned to each of the divided areas with respect to measurement points, but in Formula (6), a number m is sequentially assigned to the measuring points of all the divided areas. n is the number of the divided area in which the heater HT is installed. CD _m corresponds to CD _i,j and denotes the CD of the measurement point numbered m. τ _n corresponds to τ ₁ , and indicates the temperature of the heater HT of the divided region numbered n. a _m,n corresponds to a _i,j,l and represents a coefficient. A _{10_m} corresponds to A _{10_ i,j} and represents the average value of the CD measured at three or more temperatures of the measurement point number m, respectively.

In substrate processing such as plasma etching, it is preferable that the CD range on the entire surface of the wafer W is small, and that the CD average value is close to the target value as the target dimension. Therefore, the temperature of the heater HT in each divided region at which CD _m is approximately the target value [μ(CD _m ≒ μ)] for all measurement points is T ^* _n . From the above formula (5-2), it is assumed that τ ^* _n has a relationship of the following formula (7).

In the CD of each measurement point, there may be an error with respect to the target value mu due to variations in the CD of each measurement point before substrate processing, influence of substrate processing, or the like. For this reason, CD _m of each measurement point when the temperature of the heater HT of each divided area|region is set to τ ^* _n can be expressed by the following formula|equation (8).

Here, ε _m is the CD error with respect to the target value μ at the measurement point number m.

From Formula (8), the sum of the squares of the error of each measurement point can be expressed like the following Formula (9).

The point at which the sum of squares of the errors shown in Expression (9) becomes the minimum is the point at which it becomes the minimum value. At the local minimum, equation (9) satisfies the following equations (10-1) and satisfies equations (10-1) to (10-2).

Formula (10-2) can be represented as following Formula (11-1), when x _l,n is represented by Formula (11-2) and y _l is represented by Formula (11-3). For example, in the case where there are 400 measurement points, in the formulas (11-2) and (11-3), the total with m being 1 to 400 is calculated.

Here, l is the number of the divided area in which the heater HT is installed. For example, when there are 20 divided regions in which the heater HT is provided, l=1 to 20.

This formula (11-1) can be expressed as a matrix calculation like the following formula (12).

The matrix shown in Equation (12) can be converted into a matrix of Equation (13) below by obtaining an inverse matrix.

x _l,n of the matrix can be calculated by substituting a _i,j,l corresponding to a _m,l and a _m, l into Equation (11-2). The y _l of the matrix can also be calculated by substituting a _i,j,l corresponding to a _m,l and A _{10_ i,j} corresponding to A _{10_m} into Equation (11-3).

The calculation unit 102b solves the matrix of Equation (13) to calculate the temperature (τ ^* _n ) of the heater HT in each divided region at which the sum of squares of the error is the minimum.

However, even when the sum of squares of the error is minimized, there are cases where the CD range is not small. It is a figure explaining an example of the relationship between the sum of squares of an error, and a range. The horizontal axis of FIG. 7 is the number of the measurement point. The vertical axis of FIG. 7 is the CD at the measurement point. The error at each measurement point is the difference between the target value (μ) and CD. When the sum of squares of the error is minimized, it is sufficient that the error at each measurement point becomes smaller as a whole. For this reason, for example, as shown in FIG. 7 , even when an error is large with respect to the target value μ at one measurement point, when the error is small with respect to the target value μ at a plurality of other measurement points, the sum of squares of the error becomes small. . On the other hand, the CD range is the difference between the CD maximum value and the CD minimum value. In the case of the example of Fig. 7, the range of the CD is not small.

However, there is a strong positive correlation between the CD range and the dispersion of the error. It is considered that the temperature of the heater HT of each divided region at which the CD range is the minimum is around the temperature (τ ^* _n ) of the heater HT of each divided region at which the sum of squares of errors is minimized.

Therefore, the calculation unit 102b sets the temperature (τ ^* _n ) of the heater HT in each divided region at which the sum of squares of the error is the minimum, respectively, as a reference, and the temperature T _n of the heater HT in each divided region. ) to calculate the target temperature of the heater HT in each divided area at which the CD range of each measurement point is the smallest. For example, the calculator 102b may change the temperature of the heater HT by a predetermined temperature to be positive and negative individually by using the temperature (τ ^* _n ) of the heater HT in each divided area as a reference, respectively, and each The CD of the measurement point is calculated, and the combination of the temperatures of the heaters HT in each of the divided regions in which the CD range is the smallest is specified. The predetermined temperature may be a fixed value, may change according to processing conditions, or may be settable from an external device. In this embodiment, the predetermined temperature is set to 1 degree. The calculation unit 102b sets, as an initial value, a value obtained by adding a random number individually to the specified combination of temperatures of the heaters HT in each divided region and to the temperatures of the heaters HT in each divided region as an initial value, for example, The target temperature of the heater HT of each divided area in which the CD range is the smallest is calculated using the GRG method (Generalized Reduced Gradient method). In addition, with respect to the specified combination of the temperatures of the heaters HT in each of the divided regions, the calculator 102b sets the temperature of the heaters HT in each of the divided regions to a temperature range smaller than the predetermined temperature at random, or It is also possible to calculate the target temperature of the heater HT in each divided area in which the CD range is the smallest by repeating the calculation of the CD of each measurement point by changing the rule.

The plasma control unit 102c controls each unit of the substrate processing apparatus 10 to control plasma processing. For example, the plasma control unit 102c reads a recipe or the like according to the plasma etching to be performed from the storage unit 104 , and controls each unit of the substrate processing apparatus 10 based on the read recipe or the like.

The heater control unit 102d is, under the control of the plasma control unit 102c, when performing plasma etching on the wafer W placed in the placement area 18a of the placement table 16, the heater HT in each divided area. ) is controlled to be the target temperature calculated by the calculator 102b. For example, the heater control unit 102d controls the heater power supply HP so that electric power according to each target temperature is supplied to each heater HT.

The wafer W subjected to plasma etching is conveyed to the measurement device 11 . The measurement apparatus 11 measures the CD of the measurement point of the transferred wafer W, and transmits the measured CD data to the substrate processing apparatus 10 .

The calculation unit 102b determines whether the CD range is within an allowable range from the CD data received from the measurement device 11, and if the CD range is not within the allowable range, corrects the predictive model. For example, the calculation unit 102b adds the value of the CD-target value μ of each measurement point to the function of each measurement point of each prediction model, and again the heater ( Calculate the temperature (τ ^* _n ) of HT). Then, the calculation unit 102b sets the temperature (τ ^* _n ) of the heater HT in each divided region at which the sum of squares of the error is the minimum, respectively, as a reference, and the temperature T _n of the heater HT in each divided region. ) to calculate the target temperature of the heater HT in each divided area at which the CD range of each measurement point is the smallest. In the substrate processing apparatus 10 according to the present embodiment, as a result of plasma etching the wafer W at the calculated target temperature of the heater HT in each divided region, the CD range of the measurement point of the wafer W is If it is not within the tolerance, the predictive model is regenerated.

[Flow of temperature control]

Next, a temperature control method using the substrate processing apparatus 10 according to the first embodiment will be described. 8 is a flowchart showing an example of the flow of the temperature control method according to the first embodiment.

The generation unit 102a initializes the error flag EF to 0 (step S10). The generator 102a uses the temperature of each heater HT as a parameter, and determines the influence of the temperature of the heater HT in the adjacent divided area according to the distance between the measurement point and the divided area adjacent to the divided area including the measurement point. In addition, a function for predicting the temperature of the measurement point is obtained (step S11). In the present embodiment, the generation unit 102a obtains a function for predicting the CD of the measurement point as a linear function of the temperature T of each heater HT. For example, the generation unit 102a obtains Expressions (5-1), (5-2), and (5-3).

The generation unit 102a divides the heaters HT in each divided region into several levels and acquires data obtained by measuring CDs of measurement points of the wafer W subjected to plasma etching (step S12). For example, the substrate processing apparatus 10 controls each heater HT, divides the temperature of each divided region into several levels, exchanges the wafer W at each temperature, and actually performs plasma etching. carried out individually. Each wafer W subjected to plasma etching at each temperature is moved to the measurement device 11, and a predetermined position of the wafer W is used as a measurement point, and the CD of the measurement point is measured by the measurement device 11 . The measurement apparatus 11 transmits the measured data of the CD of each measurement point to the substrate processing apparatus 10 . The generation unit 102a receives the CD data of each measurement point measured from the measurement device 11, and divides the heater HT of each divided region into several levels of measurement points of the wafer W subjected to plasma etching. Acquire the measured data for each CD of

The generation unit 102a generates a predictive model from the acquired data (step S13). For example, the generation unit 102a performs fitting with respect to the obtained function using the measured CD of each measurement point and the temperature of each heater HT, and predicts the CD of the measurement point from the temperature of each heater HT. It is obtained as a predictive model.

The calculator 102b initializes the counter i to 1 (step S14). Then, the calculation unit 102b uses the generated prediction model, and the temperature (τ ^* _n ) of the heater HT in each divided region at which the sum of squares of the error of the CD of each measurement point with respect to the target value μ is minimized. is calculated (step S15).

The calculator 102b calculates the temperature of the heater HT in each divided region as a reference (τ ^* _n ), respectively, and sets the temperature of the heater HT as a plus and minus a predetermined temperature (eg, 1 degree). The CD of each measurement point is calculated by changing it, and the combination of the temperatures of the heaters HT in the respective divided regions with the smallest CD range is specified (step S16).

The calculation unit 102b individually calculates and adds random numbers to the specified temperatures of the heaters HT in each of the divided regions (step S17). The calculation unit 102b calculates the temperature of the heater HT in each divided region having the smallest CD range, for example, according to the GRG method, using the value obtained by adding the random number as the initial value (step S18).

The calculation unit 102b obtains the average value of CDs at each measurement point when the temperature at which the heater HT of each divided region is calculated, and determines whether the average value of CDs is less than the upper limit of the required specification (step S19). . When the average value of the CD is not less than the upper limit of the required specification (step S19: No), the calculator 102b subtracts a predetermined value from the target value μ (step S20).

On the other hand, if the average value of the CD is less than the upper limit of the requested specification (step S19: Yes), the calculation unit 102b determines whether the average value of the CD is greater than the lower limit of the requested specification (step S21). When the average value of the CD is equal to or less than the lower limit of the required specification (step S21: No), the calculation unit 102b adds a predetermined value to the target value μ (step S22).

On the other hand, when the average value of CD is larger than the lower limit of the required specification (step S21: Yes), the calculation unit 102b saves the data of the average value of CD, the range of CD, and the temperature of the heater HT in each divided area. (Step S23).

The calculation unit 102b determines whether or not the counter i is smaller than a predetermined number of processing N (step S24). When the counter i is smaller than the predetermined number of processing N (step S24: Yes), the calculator 102b adds 1 to the counter i (step S25), and the flow advances to the above-described step S15.

When the counter i is equal to or greater than the predetermined number of processing N (step S24: No), the calculation unit 102b calculates the temperature of the heater HT in each divided area of the data having the smallest CD range among the stored data. is adopted as the target temperature (step S26).

The heater control unit 102d controls the wafer W placed in the placement area 18a of the placement table 16 to become a target temperature adopted by the heater HT in each divided area when plasma etching is performed ( step S27).

The wafer W subjected to plasma etching is conveyed to the measurement device 11 . The measurement apparatus 11 measures the CD of the measurement point of the transferred wafer W, and transmits the measured CD data to the substrate processing apparatus 10 .

The calculation unit 102b determines whether the CD range is within an allowable range from the CD data received from the measurement device 11 (step S28). If the CD range is not within the allowable range (step S28: No), the calculation unit 102b determines whether the error flag EF is 0 (step S29). When the error flag EF is 0 (step S29: Yes), the generation unit 102a adds the measured data of the CD and the temperature of the heater HT as data for generating the prediction model (step S30), and then again The process proceeds to step S13, and the prediction model is regenerated from the measured data of the CD and the temperature of the heater HT, and the data acquired in step S12.

On the other hand, when the CD range is within the allowable range (step S28: Yes), the calculator 102b initializes the error flag EF to 0 (step S31). Then, the calculation unit 102b waits for a predetermined period of processing (step S32). The predetermined period may be, for example, a period in which plasma etching of a predetermined number of wafers W is performed, or may be a period in which a predetermined time passes.

The substrate processing apparatus 10 performs plasma etching of the wafer W by controlling it to become a target temperature adopted by the heater HT of each divided region for a predetermined period.

The calculation unit 102b determines whether the range of the CD is within an allowable range from the data of the CD received from the measurement device 11 after a predetermined period (step S33). If the range of the CD is within the allowable range (step S33: Yes), the flow advances to step S32 again, and processing waits for a predetermined period.

On the other hand, when the CD range is not within the allowable range (step S33: No), the calculation unit 102b sets the error flag EF to 1 (step S34). The calculation unit 102b corrects the predictive model (step S35). For example, the calculation unit 102b performs correction by adding the value of the CD-target value μ of each measurement point to the function of each measurement point of each predictive model. Then, the calculation unit 102b proceeds to step S14 again to calculate the target temperature again.

On the other hand, when the error flag EF is not 0 (step S29: No), the CD range is not within the allowable range even with the corrected predictive model. In this case, since the generation unit 102a cannot generate an appropriate predictive model from the acquired data, it outputs an error (step S36) and ends the processing. For example, the generating unit 102a transmits a message to the user interface 103 stating that the data of the measurement points of the wafer W subjected to plasma etching by dividing the heaters HT in each divided region by a number level should be acquired again. ), and the process ends.

When an error is output, the process manager controls each heater HT of the substrate processing apparatus 10, divides the temperature of each divided region by a number level, exchanges the wafer W at each temperature, and , the plasma etching actually performed is separately performed and the data for generating a predictive model is acquired again, and then the temperature control method according to the present embodiment is implemented.

As described above, in the substrate processing apparatus 10 according to the first embodiment, when plasma etching is performed on the wafer W placed on the mounting surface of the mounting table 16 , the wafer W is measured at a predetermined measurement point. Using CD as a parameter, the temperature of the heater HT of each divided area, the influence of the temperature of the heater HT of the adjacent divided area according to the distance between the measurement point and the divided area adjacent to the divided area including this measurement point The target temperature of the heater HT of each divided region in which the CD of the measurement point satisfies a predetermined condition is calculated using the predictive model to be predicted in addition. The substrate processing apparatus 10 controls the heater HT of each divided region to reach a target temperature when plasma etching is performed on the wafer W disposed on the arrangement surface. Accordingly, the substrate processing apparatus 10 can control the temperature of the heater HT of each divided region so that the CD of the measurement point of the wafer W satisfies a predetermined condition.

Further, the substrate processing apparatus 10 according to the first embodiment calculates the temperature of the heater HT in each divided region at which the sum of squares of the error of the CD of each measurement point with respect to the target dimension is minimized using the predictive model. . The substrate processing apparatus 10 changes the temperature of the heater HT of each divided area based on the calculated temperature of each divided area, respectively, and each divided area in which the difference between the maximum and minimum CD values at each measurement point becomes the smallest. Calculate the target temperature of the heater. Accordingly, the substrate processing apparatus 10 can accurately calculate the temperature of the heater HT at which the CD uniformity of the wafer W is increased.

Further, the substrate processing apparatus 10 according to the first embodiment controls the heater HT of each divided region to three or more temperatures to measure the CD of the measurement point when plasma etching is performed on the wafer W, respectively. A predictive model is created from one data. The substrate processing apparatus 10 calculates the target temperature of the heater HT of each divided region in which the CD of the measurement point satisfies a predetermined condition by using the generated predictive model. Accordingly, the substrate processing apparatus 10 can generate a predictive model capable of accurately predicting the CD at the measurement point.

(Second embodiment)

Next, a second embodiment will be described. The substrate processing system 1 and the substrate processing apparatus 10 according to the second embodiment include the structures of the substrate processing system 1 and the substrate processing apparatus 10 according to the first embodiment shown in FIGS. 1 to 4 ; Since they are the same, description is abbreviate|omitted.

Next, a predictive model according to the second embodiment will be described. The temperature T of each heater HT and the CD of the measurement point have a relationship of the following formula (14).

Here, A' is the coefficient of the exponential function of the reciprocal of the absolute temperature of the heater. B' is the activation energy, and in the case of CD, it is about the size of the physisorption energy. Specifically, B'≈0.25 [eV] x 1.7E4 [K/eV] = about 4.3E3K.

CD can be expressed as Equations (14) to (15).

Here, CD ₀ is an integer term of CD.

The exp(B'/T) of the formula (15) is the difference (τ) from the average temperature (T _a ) of three or more temperatures for which CD is measured as in the following formula (16-1), and the temperature (T) is In this case, it can be expressed as in the following formula (16-2).

Equation (16-2) can be expressed as Equation (17-1) below when x is expressed as in Equation (17-2) below.

Formula (17-1) can be approximated like the following Formula (18-1), and can be represented like Formula (18-2).

For example, when the average temperature (T _a ) = 300 [K] and τ = 10 [K], for example, the first term of x in Equation (18-2) becomes 0.47, and the second term of x is 0.11 , and the cubic term becomes 0.02, and the larger the order of x, the smaller the value.

For example, when Equation (18-2) is approximated to the quadratic term of x, it can be expressed as Equation (19) below.

Therefore, Equation (15) can be expressed as Equation (20) below when Equation (19) is used for exp(B'/T).

Moreover, when more precision is requested|required, you may approximate using exp(B'/T) up to the term larger than the quadratic of Formula (18-2). In addition, as exp(B'/T), the exponential function may be used as it is.

In Formula (20), when A ₂₀ is expressed as in Formula (21-2) below, A ₂₁ is expressed as below Formula (21-3), and A ₂₂ is expressed as below Formula (21-4) , can be expressed as in the following formula (21-1).

As shown in Expression (21-1), CD can be approximated by _a quadratic function of τ in the vicinity of the average temperature Ta .

When the expression (21-1) is expressed as the expression of CD _i,j of each measurement point of each divided region in which the heater HT is provided, it can be expressed as in the following expression (22).

Here, i is the number of the divided area in which the heater HT including the measurement point is installed. j is the number of measurement points included in the divided area where the heater HT is installed.

The generation unit 102a generates a first prediction model in which the CD of the measurement point is modeled as a linear function of the temperature of the heater HT from the received CD data. For example, in the same manner as in the first embodiment, the generation unit 102a performs the plasma etching process for each heater HT received from the measurement device 11 at three temperatures of 45°C, 50°C, and 55°C. Based on the data of the CD of the measurement point of each wafer W, fitting is performed using the CD of each measurement point and the temperature of each heater HT, and as a first predictive model, the temperature T of each heater HT is Find a function that predicts the CD of the measurement point as a linear function. For example, the generation unit 102a obtains Expressions (5-1), (5-2), and (5-3) as the first predictive model.

In addition, the generation unit 102a models the CD of the measurement point as a second or higher function of the temperature of the heater HT, or the exponential function of the reciprocal of the absolute temperature of the heater and the sum of integers, from the received CD data. 2 Create a predictive model. For example, the generation unit 102a sets each heater HT received from the measurement device 11 at three temperatures of 45°C, 50°C, and 55°C to measure points of each wafer W subjected to the plasma etching process. Based on the CD data of , fitting is performed using the CD of each measurement point and the temperature of each heater HT to obtain the values of the coefficients (A _{20_ i,j} , A _{21_ i,j} , A _{22_i,j} ).

When the coefficients (A _{20_ i,j} , A _{21_ i,j} , A _{22_ i,j} ) are obtained, from the above-mentioned equation (16-1) and the above-mentioned equation (22), CD _i at the temperature (T _l ) _,j can be calculated.

In addition, when more precision is required, the generating unit 102a performs fitting using an approximated expression using up to the second-order term of Equation (18-2) for exp(B'/T), and performs fitting to the second predictive model. may be created. In addition, the generation unit 102a may use the exponential function as exp(B'/T) as it is, perform fitting, and generate the second predictive model.

The calculation unit 102b uses the first prediction model and the second prediction model generated by the generation unit 102a to determine the target temperature of the heater HT of each divided region in which the CD of the measurement point satisfies a predetermined condition. Calculate. For example, the calculation unit 102b uses the first predictive model as in the first embodiment, and the heater HT of each divided region in which the sum of squared errors of the CD of each measurement point with respect to the target value μ becomes the minimum. ) to calculate the temperature (τ ^* _n ).

Then, the calculation unit 102b changes the temperature of the heater HT in each divided region based on the calculated temperature of the heater HT in each divided region, and uses the second prediction model to determine the threshold of each measurement point. The target temperature of the heater of each divided area at which the difference between the maximum value and the minimum value of the dimension is smallest is calculated. For example, the calculation unit 102b sets the temperature (τ ^* _n ) of the heater HT in each divided area at which the sum of squares of the error is the minimum as a reference, respectively, and the temperature T _n of the heater HT in each divided area. ) to calculate the target temperature of the heater HT in each divided region at which the CD range of each measurement point is the smallest using the above equations (3) and (22). For example, the calculation unit 102b changes the temperature of the heater HT in each of the divided regions by a predetermined temperature (τ ^* _n ) in each of the divided regions as a plus and minus, respectively, and each measurement point. CD is calculated, and the combination of the temperatures of the heaters HT in each of the divided regions in which the CD range is the smallest is specified. Then, with respect to the specified combination of the temperatures of the heaters HT in each of the divided regions, the calculation unit 102b sets, as an initial value, a value obtained by adding a random number to the temperature of the heaters HT in each of the divided regions as an initial value, for example, GRG The method is used to calculate the target temperature of the heater HT in each divided region in which the CD range is the smallest. In addition, with respect to the specified combination of the temperatures of the heaters HT in each of the divided regions, the calculator 102b sets the temperature of the heaters HT in each of the divided regions to a temperature range smaller than the predetermined temperature at random, or It is also possible to calculate the target temperature of the heater HT in each divided area in which the CD range is the smallest by repeating the calculation of the CD of each measurement point by changing the rule.

[Flow of temperature control]

Next, a temperature control method using the substrate processing apparatus 10 according to the second embodiment will be described. 9 is a flowchart showing an example of the flow of the temperature control method according to the second embodiment. In the temperature control method according to the second embodiment, since some processes are the same as those of the temperature control method according to the first embodiment shown in FIG. 8, the same reference numerals are attached to the same processes and descriptions are omitted, and mainly different processes are used. part is explained.

The generation unit 102a uses the first prediction model in which the CD of the measurement point is modeled as a linear function of the temperature of the heater HT from the acquired data and the CD of the measurement point as a second or higher function of the temperature of the heater HT, or, A second prediction model modeled by the sum of the exponential function of the reciprocal of the absolute temperature of the heater and the integer is generated (step S13a). For example, the generation unit 102a performs fitting with respect to the obtained function using the measured CD of each measurement point and the temperature of each heater HT, and the measurement point is a linear function of the temperature T of each heater HT. A function for predicting the CD and a function for predicting the CD of the measurement point as a quadratic function of the temperature T of each heater HT are respectively obtained.

The calculator 102b uses the generated first predictive model, and the temperature (τ ^* _n ) of the heater HT in each divided region at which the sum of squares of the error of the CD of each measurement point with respect to the target value μ is minimized. is calculated (step S15a).

The calculation unit 102b sets the temperature of the heater HT in each divided region (τ ^* _n ) as a reference, respectively, and sets the temperature of the heater HT into positive and negative values individually using the second prediction model. The CD of each measurement point is calculated by changing by a predetermined temperature (for example, by 1 degree), and the combination of the temperature of the heater HT in each divided area in which the CD range is the smallest is specified (step S16a).

The calculation unit 102b uses the value obtained by adding the random number as an initial value, and calculates the temperature of the heater HT in each divided region in which the CD range is the smallest by using the second prediction model, for example, according to the GRG method. do (step S18a).

In this way, the substrate processing apparatus 10 according to the second embodiment generates a first predictive model in which the CD of the measurement point is modeled as a linear function of the temperature of the heater HT. Further, the substrate processing apparatus 10 generates a second predictive model in which the CD of the measurement point is modeled as a quadratic function of the temperature of the heater HT. Since the second predictive model is modeled as a quadratic function, the CD can be predicted more accurately than the first predictive model. The substrate processing apparatus 10 calculates the temperature of the heater HT of each divided region at which the sum of squares of errors of CD is minimized by using the first prediction model. As a 2nd predictive model, the temperature of the heater HT of each division area at which the sum of squares of an error becomes the minimum may not be computed in some cases. For this reason, the substrate processing apparatus 10 calculates the temperature of the heater HT of each division area at which the sum of squares of an error becomes the minimum using a 1st prediction model. The substrate processing apparatus 10 changes the temperature of the heater HT of each divided area based on the calculated temperature of each divided area, respectively, and uses the second prediction model to determine the maximum and minimum CD values of each measurement point. The target temperature of the heater HT in each divided area at which the difference is the smallest is calculated. Accordingly, the substrate processing apparatus 10 accurately determines the temperature of the heater HT at which the CD uniformity of the wafer W becomes higher than when the target temperature of the heater HT is calculated using the first prediction model. can be calculated.

(Third embodiment)

Next, a third embodiment will be described. Since the substrate processing system 1 which concerns on 3rd Embodiment is the same as the structure of the substrate processing system 1 which concerns on 1st Embodiment and 2nd Embodiment shown in FIG. 1, description is abbreviate|omitted.

The structure of the substrate processing apparatus 10 which concerns on 3rd Embodiment is demonstrated. 10 is a diagram schematically illustrating a substrate processing apparatus according to a third embodiment. Since the substrate processing apparatus according to the third embodiment has the same configuration as the substrate processing apparatus 10 according to the first and second embodiments shown in FIG. 2 , the same reference numerals are assigned to the same parts. The description is omitted and mainly other parts will be described.

In the substrate processing apparatus 10 , a first mounting table 116 is provided in a processing container 12 . The first mounting table 116 is formed in a substantially disk shape with an upper surface about the same size as the wafer W. As shown in FIG. The first mounting table 116 corresponds to the mounting table 16 shown in FIG. 2 , and includes a support member 18 and a base 20 .

In addition, in the substrate processing apparatus 10 , the second mounting table 120 is provided around the outer peripheral surface of the first mounting table 116 . The second mounting table 120 is formed in a cylindrical shape whose inner diameter is larger than the outer diameter of the first mounting table 116 by a predetermined size, and is arranged in the same axis as the first mounting table 116 . The second mounting table 120 is a mounting surface 120a on which a ring member arranged so that the upper surface surrounds the wafer W is disposed. In the present embodiment, an annular focus ring FR is disposed on the mounting surface 120a as a ring member.

The second mounting table 120 includes a base 121 and a focus ring heater 122 . The base 121 is made of, for example, aluminum having an anodized film formed on its surface. The base 121 is supported on the support 4 . The focus ring heater 122 is supported by the base 121 . The focus ring heater 122 has an annular shape with a flat upper surface, and the upper surface serves as an arrangement surface 120a on which the focus ring FR is disposed. The focus ring heater 122 includes a heater HT2 and an insulator 123 . The heater HT2 is installed inside the insulator 123 and is included in the insulator 123 .

11 is a plan view showing a first mounting table and a second mounting table according to a third embodiment. As described above, the upper surface of the first mounting table 116 is formed in a substantially disk shape having the same size as that of the wafer W, and an arrangement region 18a is provided. The arrangement area 18a is a substantially circular area in plan view. A wafer W is placed on the upper surface of the arrangement area 18a. The second mounting table 120 is formed in a substantially cylindrical shape to surround the first mounting table 116 , and provides an outer peripheral region 18b. The outer peripheral region 18b is an annular region in plan view. A focus ring FR is disposed on the upper surface of the outer peripheral region 18b.

The arrangement area|region 18a is divided|segmented into a some division area similarly to 1st Embodiment and 2nd Embodiment, and heater HT1 is provided in each division area. The heater HT1 corresponds to the heater HT shown in FIG. 2 .

The outer peripheral region 18b is also divided into a plurality of divided regions, and a heater HT2 is provided in each of the divided regions. For example, as shown in FIG. 11 , the outer peripheral region 18b is divided into a plurality of divided regions in the circumferential direction, and a heater HT2 is provided in each divided region. Here, the division method of the division|segmentation area shown in FIG. 3 is an example, and is not limited to this. The outer peripheral region 18b may be divided into more divided regions. For example, the outer peripheral region 18b may be divided into divided regions having a smaller angular width and a narrower radial width as it approaches the outer periphery.

The heater HT1 and the heater HT2 are individually connected to the heater power supply HP shown in FIG. 11 via a wiring not shown. Each heater HT1 and each heater HT2 are supplied with individually adjusted electric power from the heater power supply HP.

The operation of the substrate processing apparatus 10 configured as described above is collectively controlled by the control unit 100 . The control unit 100 has the same configuration as the control unit 100 according to the first and second embodiments shown in FIG. 4 , and includes a communication interface 101 , a process controller 102 , and a user interface ( 103) and a storage unit 104 are provided.

The process controller 102 functions as various processing units by operating the control program. For example, the process controller 102 has the functions of a generation unit 102a , a calculation unit 102b , a plasma control unit 102c , and a heater control unit 102d .

However, in substrate processing such as plasma etching, when the temperature of the focus ring FR is controlled by installing the heater HT2 on the second mounting table 120 as in the substrate processing apparatus 10 according to the present embodiment, The progress of the processing in the vicinity of the outer periphery of the wafer W also changes depending on the temperature of the heater HT2. For example, in plasma etching, when the temperature of the heater HT2 is made high, the temperature of the focus ring FR rises. In the plasma etching, when the temperature of the focus ring FR rises, plasma is consumed near the upper portion of the focus ring FR, and as the plasma concentration near the outer periphery of the wafer W decreases, the wafer W A phenomenon in which the progress of etching in the vicinity of the outer periphery of is reduced occurs.

As described above, in plasma etching, when the temperature of the wafer W increases, the etching proceeds faster. However, when the temperature of the focus ring FR is increased, the etching proceeds in the vicinity of the outer periphery of the wafer W conversely decreases.

Therefore, in the substrate processing apparatus 10 according to the present embodiment, using the temperature of each heater HT1 and each heater HT2 as a parameter, the CD range of the entire surface of the wafer W is smaller, and A situation in which the average value of the CD is close to the target value is realized.

Here, the predictive model will be described. When the influence of the temperature of the heater HT1 and the heater HT2 is taken into account, the CD of the measurement point has the relationship of the following formula|equation (23).

Here, CD ₀ is a term (model part) for predicting the CD of the measurement point from the temperature T of the heater HT1. Equation (5-1) described above corresponds to an equation used for prediction of CD ₀ . T _FR is the temperature of the heater HT2 of the focus ring FR. ∂CD/∂T _FR ·ΔT _FR is a term (model part) that predicts the effect of the temperature of the heater HT2 of the focus ring FR part on the CD.

When the influence of the temperature of the heater HT1 in the other divided regions is taken into account, the CD is, as described above, in the vicinity of the average temperature Ta of three or more temperatures at which the temperature T of the measurement point _is measured. As shown in Equation (21-1), it can be approximated by a quadratic function of tau. Therefore, further adding the influence of the temperature of the heater HT2, CD is in the vicinity of the average temperature Ta of three or more temperatures at which the temperature T of the measurement point _is measured CD, and the temperature of the heater HT2 When (T _FR ) is in the vicinity of the average temperature (T _{FR _a} ) of the heater HT2 for which CD is measured, it can be approximated by a linear function using τ and ξ as in the following Equation (24-1). . In addition, CD can be approximated by a quadratic function using τ and ξ as shown in the following equation (24-2).

Here, τ _is the difference between the temperature T of the measurement point and the average temperature Ta , as shown in the above formula (16-1). ξ is a temperature in which the temperature T _FR of the heater HT2 when CD is measured as a difference from the average temperature T _{FR _a} , and ξ = T _FR -T _{FR _ a} .

Equation (24-1) is a model approximated by a linear function. The terms 1 and 2 on the right side of the equation (24-1) are the equations on the right side of the above-mentioned equation (4-1), and are terms for predicting the CD of the measurement point from the temperature τ of the heater HT1. A ₁₀ and A ₁₁ are coefficients. The third term on the right side of the equation (24-1) is a term for predicting the influence on CD from the temperature ξ of the heater HT2. F ₁₁ is the coefficient.

Equation (24-2) is a model approximated by a quadratic function. The terms 1 to 3 on the right side of the equation (24-2) are the equations on the right side of the above equation (21-1), and are terms for predicting the CD of the measurement point from the temperature τ of the heater HT1. Terms 4 to 5 on the right side of Equation (24-2) are terms for predicting the influence on CD from the temperature ξ of the heater HT2. F ₂₁ and F ₂₂ are coefficients.

Equation (24-2) is obtained individually as an equation for obtaining the CD of each measurement point in each divided area.

In the substrate processing apparatus 10 according to the present embodiment, in order to obtain data used for generation of a predictive model, each heater HT1 and heater HT2 are controlled, and the temperature of each divided region is set to a number level. After dividing, the wafers W are exchanged at each temperature, and plasma etching actually performed for each wafer W is individually performed. For example, the substrate processing apparatus 10 makes the temperature of each heater HT2 constant, controls each heater HT1 to three or more temperatures, exchanges the wafer W at each temperature, and actually implements it. Plasma etching is performed separately. As an example, the substrate processing apparatus 10 plasma-etches the wafer W by setting each heater HT1 to 50 degreeC. In addition, the substrate processing apparatus 10 plasma-etches the wafer W by setting the respective heaters HT1 to 55°C. In addition, the substrate processing apparatus 10 plasma-etches the wafer W by setting each heater HT1 to 45 degreeC. In addition, the substrate processing apparatus 10 makes the temperature of each heater HT1 constant, controls each heater HT2 to two or more temperatures, exchanges the wafer W at each temperature, and actually implements it. Plasma etching is performed separately.

Each wafer W subjected to plasma etching at each temperature is respectively conveyed to the measuring device 11 . The measurement device 11 measures the CD of the measurement point using a predetermined position as the measurement point with respect to each conveyed wafer W. As shown in FIG. The measurement apparatus 11 transmits the measured CD data of each measurement point to the substrate processing apparatus 10 .

Thereby, as shown in the following formula (25) for each measurement point, data in which τ, τ ² , ξ, ξ ² and CD values of the measurement points are associated can be obtained.

Here, n is the number of wafers W subjected to plasma etching in order to obtain data used for generating a predictive model. τ _n is the temperature τ of the heater HT1 in the divided region provided with the measurement point when plasma etching is performed on the n-th sheet of wafer W. ξ _n is the temperature ξ of the heater HT2 when plasma etching is performed on the n-th sheet of wafer W. CD _n is the CD value of the measurement point when plasma etching is performed on the n-th sheet of wafer W.

The generation unit 102a generates, from the received CD data, a first predictive model in which the CD of the measurement point is modeled as a linear function of the temperatures of the heaters HT1 and HT2. For example, the generation unit 102a uses the CD of each measurement point and the temperatures of the heaters HT1 and HT2 to fit the equation (24-1) to the coefficients A ₁₀ , A ₁₁ , F ₁₁ ) is obtained, and the obtained coefficients (A ₁₀ , A ₁₁ , F ₁₁ ) are substituted into Equation (24-1), and as a first prediction model, the temperature (τ) of the heater (HT1) and the heater (HT2) Find a function that predicts the CD of the measurement point as a linear function of the temperature (ξ) of For example, the generation unit 102a obtains Equation (24-1) as the first predictive model.

Further, the generation unit 102a generates, from the received CD data, a second predictive model in which the CD of the measurement point is modeled by a quadratic function of the heater HT1 and the heater HT2. For example, for each measurement point, the generation unit 102a calculates the CD of the measurement point and the temperatures of the heaters HT1 and HT2 based on the data of the CD of the measurement points of each wafer W shown in Equation (25). By using the above equation (24-2), fitting is performed to obtain the values of the coefficients (A ₂₀ , A ₂₁ , A ₂₂ , F ₂₁ , F ₂₂ ). For example, the generating unit 102a performs fitting to obtain the values of the coefficients A ₂₀ , A ₂₁ , A ₂₂ , F ₂₁ , F ₂₂ having the minimum residual sum of squares.

For example, S _ik and S _ki are defined as in Equation (26-1) below, S _iCD is defined as Equation (26-2) below, and S _i1 is defined as Equation (26-3) below. , let x _i2 be the following formula (26-4), x _i3 the following formula (26-5), and x _i4 the following formula (26-6).

Here, x￣ _i is the average value of x _i . x￣ _K is the average of x _K . CD￣ is the average value of CDs.

When the residual sum of squares is the minimum, the following relations (27-1) to (27-5) are satisfied.

Expressions (27-2) to (27-5) can be transformed as in Expression (28) when a matrix is used.

The generating unit 102a generates S _ik and S _jCD for j = 1 to 4 and k = 1 to 4 from Equation (26-1) - Equation (26-6) using Equation (25) described above. The values of the coefficients (A ₂₁ , A ₂₂ , F ₂₁ , F ₂₂ ) are obtained by obtaining each, and substituting it in Equation (28).

The generation unit 102a includes the calculated coefficients A ₂₁ , A ₂₂ , F ₂₁ , F ₂₂ , the average value of τ (τ￣), the average value of τ ² (τ￣ ² ), the average value of ξ (ξ￣), By substituting the average value (ξ￣ ² ) of ξ ² into Equation (27-1), the value of the coefficient (A ₂₀ ) is obtained.

Then, the generation unit 102a generates the second predictive model by substituting the calculated coefficients A ₂₀ , A ₂₁ , A ₂₂ , F ₂₁ , and F ₂₂ into Expression (24-2).

The calculation unit 102b uses the first prediction model and the second prediction model generated by the generation unit 102a to generate a heater HT1, a heater ( Calculate the target temperature of HT2).

For example, the calculation unit 102b uses the first predictive model as in the second embodiment, and the heater HT1 of each divided region in which the sum of squared errors of the CD of each measurement point with respect to the target value μ becomes the minimum. ) and the temperature _{(ξ * n} ⁾ _of ^the heater HT2 are calculated.

Then, the calculation unit 102b changes the temperature of the heater HT1 and the heater HT2 in each divided region based on the calculated temperatures of the heater HT1 and the heater HT2 in each divided region, respectively, The target temperature of the heater HT1 and the heater HT2 of each divided area in which the difference between the maximum value and the minimum value of the critical dimension of each measurement point is the smallest using the 2nd prediction model is calculated. For example, the calculation unit 102b uses the temperature (τ ^* _n ) of the heater HT1 and the temperature ( ξ ^* _n ) of the heater HT2 in each divided region at which the sum of squares of the error is the minimum, respectively, as a reference, each The heater HT1 and heater of each divided area where the temperature of the heater HT1 and the heater HT2 of the divided area is changed, and the CD range of each measurement point is the smallest using the above-mentioned formula (24-2) Calculate the target temperature of (HT2). For example, the calculation unit 102b changes the temperature of the heater HT1 in each divided region (τ ^* _n ) as a reference, respectively, and changes the temperature of the heater HT1 by a predetermined temperature to be positive and negative individually, In addition, the temperature ξ of the heater HT2 is changed by a predetermined temperature in plus and minus values based on ξ ^* _n , the CD of each measurement point is calculated, and the heater of each divided region where the CD range is the smallest. The combination of the temperature of (HT1) and the heater (HT2) is specified. Then, the calculation unit 102b sets a value obtained by individually adding a random number to the temperature of the heater HT1 in each divided region with respect to a specific combination of the temperatures of the heater HT1 and the heater HT2 in each divided region as an initial value. Thus, the target temperatures of the heaters HT1 and HT2 in each of the divided regions in which the CD range is the smallest are calculated using, for example, the GRG method. In addition, the calculation unit 102b sets the temperatures of the heaters HT1 and HT2 of the respective divided regions to a predetermined temperature with respect to the specific combination of the temperatures of the heaters HT1 and HT2 in the respective divided regions. By repeating calculating the CD of each measurement point by changing it randomly or in a predetermined rule with a small temperature range, the target temperatures of the heaters HT1 and HT2 in each divided area where the CD range is the smallest are calculated. also good

The heater control unit 102d is, under the control of the plasma control unit 102c, a target temperature calculated by the heater HT1 and the heater HT2 by the calculation unit 102b when plasma etching is performed on the wafer W. control to be For example, the heater control unit 102d controls the heater power supply HP so that electric power according to each target temperature is supplied to each heater HT1 and each heater HT2 .

As described above, in the substrate processing apparatus 10 according to the third embodiment, a placement surface for arranging the wafer W and the focus ring FR arranged to surround the wafer W is provided, and the placement surface is divided Each of the divided areas has a mounting table (a first mounting table 116 and a second mounting table 120) provided with heaters HT1 and HT2 capable of adjusting the temperature, respectively. The substrate processing apparatus 10 determines a critical dimension at a predetermined measurement point of the wafer W when a predetermined substrate processing is performed on the wafer W disposed on the placement surface, and sets the heaters HT1 and HT2 in each divided area. ) as a parameter, and by adding the influence of the temperature of the heaters (HT1, HT2) of other divided areas according to the distance between the measurement point and other divided areas other than the divided area including this measurement point, using a predictive model to predict , calculates the target temperature of the heaters HT1 and HT2 in each of the divided regions in which the critical dimension of the measurement point satisfies a predetermined condition. The substrate processing apparatus 10 controls the heaters HT1 and HT2 of each divided region to reach the calculated target temperatures when performing substrate processing on the wafer W disposed on the placement surface. Accordingly, the substrate processing apparatus 10 can control the temperatures of the heaters HT1 and HT2 of each divided region so that the CD of the measurement point of the wafer W satisfies a predetermined condition.

(Fourth embodiment)

Next, a fourth embodiment will be described. The substrate processing system 1 and the substrate processing apparatus 10 according to the fourth embodiment are the substrate processing systems ( Since it is the same as that of 1) and the structure of the substrate processing apparatus 10, it abbreviate|omits description. Hereinafter, the fourth embodiment will be described using the configuration of the substrate processing apparatus 10 according to the first embodiment and the second embodiment shown in FIGS. 1 to 3, but the The fourth embodiment may be applied to the configuration of the substrate processing apparatus 10 according to the third embodiment.

12 is a block diagram showing a schematic configuration of a control unit that controls the substrate processing apparatus according to the fourth embodiment. Since the control part 100 which controls the substrate processing apparatus which concerns on 4th Embodiment has the same structure as the control part 100 which concerns on 1st to 3rd embodiment shown in FIG. 4, in part, regarding the same part are given the same reference numerals to omit the description, and mainly different parts will be described.

The process controller 102 of the control unit 100 that controls the substrate processing apparatus according to the fourth embodiment further has a function of the arrangement control unit 102e.

Here, as described above, in substrate processing such as plasma etching, it is required that the CD range on the entire surface of the wafer W be small. The CD range is the difference between the CD maximum value and the CD minimum value.

In the substrate processing apparatus 10 , plasma etching is performed on the wafer W by setting the temperature of the heater HT in each divided region as the target temperature calculated by the calculator 102b. Accordingly, the CD range of each measurement point of the wafer W becomes the smallest.

However, the maximum point at which CD is the maximum and the minimum point at which CD is the minimum of the measurement points of the wafer W may be located in the same divided area.

13 is a diagram schematically showing the maximum and minimum points of CDs on the wafer. Fig. 13(A) shows a maximum point P1 at which CD is the maximum and a minimum point P2 at which CD is the minimum of the measurement points on the wafer W. In FIG. 13(A) schematically shows a placement area 18a in which the wafer W of the placement table 16 is placed. The arrangement area 18a is divided into a plurality of divided areas, and a heater HT is provided in each divided area. In the present embodiment, the arrangement area 18a is divided into five divided areas: a central circular area 150 and four annular areas 151 surrounding the circular area. That is, in the mounting table 16 , at least a part (annular region 151 ) of each of the divided regions into which the mounting region 18a is divided is provided along the circumferential direction of the wafer W . A heater HT is provided in each of the divided regions (the circular region 150 and the annular region 151 ), respectively.

When the wafer W shown in Fig. 13A is placed in the arrangement area 18a, as shown in Fig. 13B, the maximum point P1 and the minimum point P2 are within the same divided area. Located. In the example of FIG. 13B , the maximum point P1 and the minimum point P2 are located within the same annular region 151 . The CD of the measurement point changes according to the temperature of the heater HT. However, when the maximum point P1 and the minimum point P2 are located in the same divided area, the CDs of the maximum point P1 and the minimum point P2 are temperature-controlled by the same heater HT, so that the heater It also changes according to the temperature change of (HT). For this reason, it is difficult to make the CD range smaller.

In this case, as shown in FIG. 13(C), if the wafer W is rotated and placed in the arrangement area 18a, the maximum point P1 and the minimum point P2 can be placed in separate divided areas. have. In the example of FIG. 13(C) , the maximum point P1 and the minimum point P2 may be arranged in separate annular regions 151 . In this way, when the maximum point P1 and the minimum point P2 are arranged in separate divided regions, the temperature can be controlled by a separate heater HT, so that the CD range can be made smaller.

Then, the arrangement|positioning control part 102e calculates the CD of each measurement point at the time of setting it as the target temperature of each heater HT using the predictive model generated by the generation|generation part 102a. Note that, for the CD of the measurement point, a value measured by the measurement device 11 by actually performing plasma etching may be used.

The arrangement control unit 102e specifies, among the CDs of each measurement point, the maximum point at which CD is the maximum and the minimum point at which CD becomes the minimum. The arrangement control unit 102e determines whether the maximum point and the minimum point are located in the same divided area. For example, the arrangement control unit 102e determines whether the maximum point and the minimum point are located within the same divided area provided along the circumferential direction of the wafer W. As a result of the determination, when the maximum point and the minimum point are located in the same divided area, the arrangement control unit 102e controls the arrangement of the wafer W with respect to the arrangement surface so that the maximum point and the minimum point are located in different divided areas. For example, when the maximum point and the minimum point are located in the same divided area provided along the circumferential direction of the wafer W, the arrangement control unit 102e may control the wafer W in the circumferential direction so that the maximum point and the minimum point are located in different divided areas. control to rotate. For example, the arrangement control unit 102e controls to rotate the wafer W in the circumferential direction so that an intermediate position between the maximum point and the minimum point is located at the boundary of the divided region. For example, in the transfer system for transferring the wafer W to the substrate processing apparatus 10 , the placement control unit 102e controls to rotate the wafer W in the circumferential direction. In the transfer system, an alignment device and a robot arm are provided in front of the substrate processing apparatus 10 . The alignment apparatus is provided with a horizontal rotation stage, and adjustment of various alignments, such as adjustment of the rotation position of the wafer W etc., is possible. The robot arm holds the wafer W and transports the wafer W to each device in the transport system. For example, the arrangement control unit 102e transmits control information for rotating the wafer W in the circumferential direction to the alignment device or the robot arm so that the intermediate position between the maximum point and the minimum point is located at the boundary of the divided area. W) is controlled to rotate in the circumferential direction.

When the arrangement of the wafer W with respect to the arrangement surface is changed in this way, the substrate processing apparatus 10 may regenerate the predictive model. For example, the substrate processing apparatus 10 controls each heater HT, divides the temperature of each divided region into several levels, exchanges the wafer W at each temperature, and actually performs plasma etching. are carried out individually. Each wafer W subjected to plasma etching at each temperature is moved to a measuring device 11, and a predetermined position of the wafer W is used as a measuring point, and the CD of the measuring point is measured by the measuring device 11 . The measurement apparatus 11 transmits the measured CD data of each measurement point to the substrate processing apparatus 10 . The generation unit 102a regenerates a predictive model from the received CD data. The calculation unit 102b may use the predictive model generated by the generation unit 102a to calculate the target temperature of the heater HT in each divided region in which the CD of the measurement point satisfies a predetermined condition.

In addition, when obtaining change characteristic data indicating a change in CD with respect to a temperature change, the substrate processing apparatus 10 uses a predictive model before changing the arrangement of the wafer W with respect to the arrangement surface, The target temperature of the heater HT may be calculated. For example, the calculator 102b specifies the heater HT corresponding to each measurement point based on the rotation angle at which the wafer W is rotated. The calculation unit 102b calculates the CD value for each measurement point based on the change characteristic data according to the difference between the temperature of the heater HT before changing the arrangement of the wafer W and the temperature of the heater HT after the change, based on the change characteristic data. Calibrate the predictive model to correct it. The calculation unit 102b may use the corrected predictive model to calculate the target temperature of the heater HT in each divided region in which the CD of the measurement point satisfies a predetermined condition.

As described above, in the substrate processing apparatus 10 according to the fourth embodiment, when the maximum point at which the CD of the measurement point of the wafer W becomes the maximum and the minimum point at which the CD becomes the minimum are located in the same divided region, the maximum point and the The arrangement of the wafer W with respect to the arrangement surface is controlled so that the minimum point is located in different divided regions. Accordingly, since the substrate processing apparatus 10 can temperature-control the maximum point at which CD becomes the maximum and the minimum point at which CD becomes the minimum by using a separate heater HT, it is preferable to make the CD range smaller. it becomes possible

As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited only to the range described in the said embodiment. It is clear to those skilled in the art that it is possible to add various changes or improvement to the said embodiment. In addition, it is clear that the form which added such a change or improvement can also be included in the technical scope of this invention from description of a claim.

For example, in the above embodiment, the case where substrate processing is performed on a semiconductor wafer as a substrate has been described as an example, but the present invention is not limited thereto. The substrate may be of any type as long as it is affected by the progress of the substrate processing by the temperature.

In addition, although the case where plasma etching is performed as a substrate processing was demonstrated as an example in the said embodiment, it is not limited to this. Substrate processing may be any as long as the progress of the processing is affected by the temperature.

In addition, in the above-described third embodiment, the case where the mounting table is divided into the first mounting table 116 on which the wafer W is placed and the second mounting table 120 on which the focus ring FR is disposed will be described as an example. However, it is not limited to this. The mounting table may be configured as one, and the wafer W and the focus ring FR may be arranged on the same mounting surface.

In addition, although the case where the focus ring FR is arrange|positioned as a ring member was demonstrated as an example in said 3rd Embodiment, it is not limited to this. The ring member may be made of, for example, an insulating material such as quartz, and may be an insulator ring provided for insulation or protection of the mounting surface. Further, the ring member may be a focus ring FR and an insulator ring. In this case, for example, an insulator ring is arranged to surround the focus ring FR.

In addition, in the above-described first to fourth embodiments, a case in which the calculation unit 102b calculates the target temperature of the heater in each divided region at which the difference between the maximum value and the minimum value of the critical dimension of each measurement point becomes the smallest Although the example was demonstrated, it is not limited to this. The calculation unit 102b may calculate the target temperature of the heater in each divided region at which the sum of squares of deviations in critical dimensions of each measurement point is the smallest.

1 Substrate processing system 10 Substrate processing apparatus
16 Mounting platform 18 Support member
18a placement area 18b outer perimeter area
18m body 20 base
100 control unit 102 process controller
102a generation unit 102b calculation unit
102c plasma control unit 102d heater control unit
116 First Station 120 Second Station
HT, HT1, HT2 Heaters

Claims (13)

a mounting table provided with a mounting surface on which one or both of the substrate and one or both of the ring members arranged to surround the substrate are provided, and a heater capable of adjusting the temperature is provided in each divided region dividing the mounting surface;
Critical dimensions at a plurality of predetermined measurement points of the substrate when predetermined substrate processing is performed on the substrate disposed on the arrangement surface, using the temperature of the heater in each divided region as a parameter, the measurement point and this measurement point Using a prediction model that predicts by adding the influence of the heater temperature of the other divided regions according to the distance between the divided regions other than the divided regions including The temperature of the heater in each divided region that becomes the minimum is calculated, the temperature of the heater in each divided region is changed based on the calculated temperature of each divided region, respectively, and the maximum and minimum values of the critical dimension of each measurement point are calculated. a calculation unit for calculating a target temperature of the heater in each divided region in which the difference or the sum of squares of the deviation of the critical dimension of each measurement point is the smallest;
A heater control unit that controls the heater of each divided region to reach a target temperature calculated by the calculation unit when the substrate disposed on the arrangement surface is subjected to substrate processing
A substrate processing apparatus comprising a. The method according to claim 1, wherein the calculation unit uses a prediction model for predicting by adding the influence of the temperature of the heater in the adjacent divided area according to the distance between the measuring point and the divided area adjacent to the divided area including the measuring point. , calculating a target temperature of the heater in each divided region in which a critical dimension of the measurement point satisfies a predetermined condition. The method according to claim 1 or 2, wherein the calculation unit changes the temperature of the heater in each divided area based on the calculated temperature of each divided area, so that the average value of the critical dimensions of each measurement point is of a predetermined specification. A substrate processing apparatus characterized by calculating the target temperature of the heater in each divided region in which the difference between the maximum value and the minimum value of the critical dimension of each measurement point or the sum of squares of the deviation of the critical dimension of each measurement point is smallest within the range. . a mounting table provided with a mounting surface on which one or both of the substrate and one or both of the ring members arranged to surround the substrate are provided, and a heater capable of adjusting the temperature is provided in each divided region dividing the mounting surface;
The substrate disposed on the placement surface from data obtained by measuring the critical dimensions of predetermined measurement points of the substrate when predetermined substrate processing is performed on the substrate by controlling the heaters in each divided region to three or more temperatures The critical dimension at the measurement point when the substrate processing is performed is determined according to the distance between the measurement point and other divided regions other than the divided region including the measurement point, using the temperature of the heater in each divided region as a parameter. a generation unit for generating a prediction model that predicts by taking into account the influence of the temperature of the heater in other divided regions;
a calculation unit configured to calculate a target temperature of the heater in each divided region in which the critical dimension of the measurement point satisfies a predetermined condition by using the prediction model generated by the generation unit;
A heater control unit that controls the heater of each divided region to reach a target temperature calculated by the calculation unit when the substrate disposed on the arrangement surface is subjected to substrate processing
A substrate processing apparatus comprising a. According to claim 4, wherein the generator, a first prediction model that models the critical dimension of the measurement point as a linear function of the temperature of the heater, and the critical dimension of the measurement point as a function of a quadratic or higher of the temperature of the heater, or generating a second prediction model modeled as the sum of the exponential function of the reciprocal of the absolute temperature and the integer;
The calculator calculates a temperature of the heater in each divided region at which the sum of squares of errors of critical dimensions is minimized using the first prediction model, and calculates the temperature of each divided region based on the calculated temperature of each divided region. and calculating the target temperature of the heater in each divided region at which the difference between the maximum value and the minimum value of the critical dimension of each measurement point is the smallest by changing the temperature of the heater and using the second prediction model. 5. The method of claim 1 or 4, wherein the substrate treatment is plasma etching;
The substrate processing apparatus according to claim 1, wherein the critical dimension is the width of the etching pattern. The substrate processing apparatus according to claim 1 or 4, wherein the ring member is one or both of a focus ring and an insulator ring. The division according to claim 1 or 4, wherein when the maximum point at which the critical dimension of the measurement point of the substrate becomes the maximum and the minimum point at which the critical dimension becomes the minimum are located in the same division area, the maximum point and the minimum point are different from each other. The substrate processing apparatus according to claim 1, further comprising a placement control unit for controlling placement of the substrate with respect to the placement surface so as to be located in the area. The method according to claim 8, wherein the substrate has a disk shape,
In the mounting table, at least a part of each divided area dividing the mounting surface is provided along a circumferential direction of the substrate,
When the maximum point and the minimum point are located in the same divided area provided along the circumferential direction of the substrate, the arrangement control unit rotates the substrate in the circumferential direction so that the maximum point and the minimum point are located in different divided areas. A substrate processing apparatus for controlling. A mounting surface is provided for arranging one or both of a substrate and a ring member arranged to surround the substrate, and a heater capable of adjusting a temperature is provided on each of the divided regions dividing the mounting surface. Critical dimensions at a plurality of predetermined measurement points of the substrate when predetermined substrate processing is performed on the substrate, using the temperature of the heater in each divided region as a parameter, the measurement point and the divided region including the measurement point Each division in which the sum of squares of the error of the critical dimension of each measurement point with respect to the target dimension is minimized using a prediction model that predicts by adding the influence of the heater temperature of the other divided regions according to the distance between the different divided regions of The temperature of the heater in the region is calculated, the temperature of the heater in each divided region is changed based on the calculated temperature of each divided region, respectively, and the difference between the maximum value and the minimum value of the critical dimension of each measurement point, or each measurement point calculating the target temperature of the heater in each divided area at which the sum of squares of deviations in critical dimensions of
Controlling the heater in each divided area to reach the calculated target temperature when the substrate disposed on the arrangement surface is subjected to substrate processing
A temperature control method characterized in that the processing is executed by a computer. A mounting surface is provided for arranging one or both of a substrate and a ring member arranged to surround the substrate, and a heater capable of adjusting a temperature is provided on each of the divided regions dividing the mounting surface. Critical dimensions at a plurality of predetermined measurement points of the substrate when predetermined substrate processing is performed on the substrate, using the temperature of the heater in each divided region as a parameter, the measurement point and the divided region including the measurement point Each division in which the sum of squares of the error of the critical dimension of each measurement point with respect to the target dimension is minimized using a prediction model that predicts by adding the influence of the heater temperature of the other divided regions according to the distance between the different divided regions of The temperature of the heater in the region is calculated, the temperature of the heater in each divided region is changed based on the calculated temperature of each divided region, respectively, and the difference between the maximum value and the minimum value of the critical dimension of each measurement point, or each measurement point calculating the target temperature of the heater in each divided area at which the sum of squares of deviations in critical dimensions of
Controlling the heater in each divided area to reach the calculated target temperature when the substrate disposed on the arrangement surface is subjected to substrate processing
A temperature control program stored in a medium, characterized in that the computer executes the processing. A mounting surface is provided for arranging one or both of a substrate and a ring member disposed so as to surround the substrate, and a heater capable of adjusting a temperature is provided in each divided region dividing the mounting surface. From the data obtained by measuring the critical dimensions of predetermined measurement points of the substrate when predetermined substrate processing is performed on the substrate by controlling the heater to three or more temperatures, the substrate processing is performed on the substrate disposed on the placement surface. When the critical dimension at the measurement point is used as a parameter, the temperature of the heater in each divided region is used as a parameter, and the distance between the measurement point and another divided region other than the divided region including the measurement point is defined as the critical dimension at the measurement point. Create a predictive model that predicts by adding the effect of the heater's temperature,
calculating the target temperature of the heater in each divided area in which the critical dimension of the measurement point satisfies a predetermined condition by using the generated prediction model;
Controlling the heater in each divided area to reach the calculated target temperature when the substrate disposed on the arrangement surface is subjected to substrate processing
A temperature control method characterized in that the processing is executed by a computer. A mounting surface is provided for arranging one or both of a substrate and a ring member disposed so as to surround the substrate, and a heater capable of adjusting a temperature is provided in each divided region dividing the mounting surface. From the data obtained by measuring the critical dimensions of predetermined measurement points of the substrate when predetermined substrate processing is performed on the substrate by controlling the heater to three or more temperatures, the substrate processing is performed on the substrate disposed on the placement surface. When the critical dimension at the measurement point is used as a parameter, the temperature of the heater in each divided region is used as a parameter, and the distance between the measurement point and another divided region other than the divided region including the measurement point is defined as the critical dimension at the measurement point. Create a predictive model that predicts by adding the effect of the heater's temperature,
calculating the target temperature of the heater in each divided area in which the critical dimension of the measurement point satisfies a predetermined condition by using the generated prediction model;
Controlling the heater in each divided area to reach the calculated target temperature when the substrate disposed on the arrangement surface is subjected to substrate processing
A temperature control program stored in a medium, characterized in that the computer executes the processing.

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