TWI772356B - Plasma processing device, temperature control method, and temperature control program - Google Patents

Abstract

An object of the invention is to control the temperature of heaters in various segmented regions such that the critical dimensions at measurement sites on a substrate satisfy predetermined conditions. A mounting stage is provided with a mounting surface on which one or both of a substrate and a ring member disposed so as to surround the substrate are mounted, and a heater capable of adjusting the temperature is provided in each segmented region obtained by dividing the mounting surface into segments. A calculation section uses an estimation model that estimates the critical dimensions at predetermined measurement sites for a substrate mounted on the mounting surface and subjected to predetermined substrate processing, while accounting for the impact of the temperature of the heaters of other segmented regions according to the distance between the measurement site and the other segmented regions besides the segmented region that includes the measurement site, and using the temperature of the heater in each segmented region as parameters, calculates the target temperature of the heater in each segmented region at which the critical dimensions of the measurement site satisfy predetermined conditions. When a substrate mounted on the mounting surface is subjected to substrate processing, the heater control section controls the heater in each segmented region so as to obtain the target temperature calculated by the calculation section.

Description

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.

The diameter of substrates such as wafers has gradually increased with the progress of semiconductor technology generations. On the other hand, transistors tend to be miniaturized. Therefore, for substrate processing, we require higher precision.

One of the precisions regarding substrate processing is, for example, the uniformity of critical dimensions within the substrate. In substrate processing, the progress of the processing varies depending on the temperature of the substrate. Therefore, in a substrate processing apparatus, in order to control the temperature of the substrate with higher accuracy, the mounting surface on which the substrate is placed on the mounting table is divided into a plurality of divided areas, heaters are installed in each divided area, and each division is adjusted. The temperature of the area, so that the critical dimension of a given position of the substrate satisfies the given condition. For example, the setting value of the heater for each divided area is obtained from a matrix describing the relationship between the control parameter of each divided area of the placement surface and the predicted temperature at a predetermined position of the substrate (for example, refer to the following Patent Document 1). [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2016-178316

[Problems to be Solved by Invention]

In addition, 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 varies due to the influence of the adjacent divided regions in the vicinity of the boundary between each divided region and adjacent divided regions. Therefore, in the conventional technology, the temperature in the vicinity of the boundary between each segmented region and the adjacent segmented region does not reach the predetermined temperature, and the critical dimension cannot be controlled to satisfy the predetermined condition in the vicinity of the boundary. As a result, in the conventional technique, the uniformity of the critical dimension within the substrate cannot be controlled with good precision.

In addition, in a substrate processing apparatus, a heater may be provided in the peripheral region of the substrate. With such a structure, the substrate processing apparatus may be affected by the heater in the peripheral area, and may not be able to control the critical dimension near the outer edge of the substrate to satisfy the predetermined condition. [means to solve the problem]

In one embodiment, the disclosed substrate processing apparatus includes a stage, a calculation unit, and a heater control unit. A mounting table is provided with a mounting surface on which one or both of a substrate and an annular member arranged so as to surround the substrate are placed, and a heater capable of adjusting the temperature is provided in each of the divided regions of the divided mounting surface. device. The calculation unit uses the temperature of the heater in each divided area as a parameter, and adds the influence of the temperature of the heater in the other divided areas corresponding to the distance between the measurement point and the other divided areas other than the divided area including the measurement point, and predicts A prediction model for the critical dimension of a predetermined measurement point of the substrate when a predetermined substrate process is performed on the substrate placed on the mounting surface, calculates the target temperature of the heater in each divided region where the critical dimension of the measurement point satisfies the predetermined condition. The heater control unit controls the target temperature calculated by the heater formation calculation unit of each divided area when the substrate processing is performed on the substrate placed on the placement surface. [Effect of invention]

According to one aspect of the disclosed substrate processing apparatus, the effect of "can control the temperature of the heater of each divided area so that the critical dimension of the measurement point of the substrate satisfies a predetermined condition" is achieved.

Hereinafter, embodiments of the substrate processing apparatus, the temperature control method, and the temperature control program disclosed in the present application will be described in detail with reference to the drawings. In addition, in each drawing, the same code|symbol is attached|subjected to the same or equivalent part. In addition, it is not limited to the invention disclosed by this embodiment. The respective embodiments can be appropriately combined within the range that the processing contents do not contradict each other.

(1st Embodiment) [Structure of a board|substrate processing system] First, the schematic structure of the board|substrate processing system of an embodiment is demonstrated. The substrate processing system is a system that performs predetermined substrate processing on substrates such as wafers. This embodiment will be described by taking, as an example, an aspect in which plasma etching is performed on a substrate as a substrate treatment. FIG. 1 is a schematic structural 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 connected to each other through the network N so as to be able to communicate with each other. The network N may be any type of communication network such as a LAN (Local Area Network) or a VPN (Virtual Private Network), regardless of whether it is wired or wireless.

The substrate processing apparatus 10 is an apparatus for performing predetermined substrate processing on a substrate. In this embodiment, the substrate processing apparatus 10 performs plasma etching on a semiconductor wafer (hereinafter referred to as a "wafer") serving as a substrate.

The measurement device 11 is a device for measuring the critical dimension (Critical Dimension) of the measurement point by taking the predetermined position of the substrate subjected to the substrate processing by the substrate processing apparatus 10 as the measurement point. In the present embodiment, the measurement device 11 measures the width of the pattern of measurement points as the critical dimension. Hereinafter, the critical dimension is also referred to as "CD". A plurality of measuring points for measuring CD are provided at different positions of the wafer. The measuring device 11 measures the width of the pattern at each measurement point. The measuring device 11 may also be an inspection device for inspecting substrate defects. The measurement device 11 transmits the data of the CD of each measurement point measured to the substrate processing device 10 .

The substrate processing apparatus 10 divides the mounting surface on which the wafer is placed into a plurality of divided areas, and performs control to adjust the temperature of each divided area based on the CD data of each measurement point received from the measurement device 11, so that the The CD of each measurement point of the wafer satisfies the predetermined condition.

[Configuration of Substrate Processing Apparatus] Next, the configuration of the substrate processing apparatus 10 will be described. FIG. 2 is a schematic diagram showing a substrate processing apparatus according to an embodiment. In FIG. 2, the structure of the longitudinal cross section of the substrate processing apparatus 10 of one embodiment is shown schematically. 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 container 12 . The processing vessel 12 is made of, for example, aluminum. In addition, the surface of the processing container 12 is anodized.

Inside the processing container 12, a mounting table 16 is provided. The mounting table 16 includes a support member 18 and a base 20 . The top surface of the support member 18 serves as a placement surface on which a substrate to be processed for a substrate is placed. In this embodiment, the wafer W to be subjected to the plasma etching process is placed on the top surface of the support member 18 . The base 20 has a roughly disk shape, and its main portion is made of, for example, a conductive metal such as aluminum. The base 20 constitutes a lower electrode. The base 20 is supported by the support portion 14 . The support portion 14 is a cylindrical member extending from the bottom of the processing container 12 .

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

In addition, the base 20 is electrically connected to the second high frequency power source LFS through the integrator MU2. The second high-frequency power supply LFS generates high-frequency power (high-frequency bias power) for introducing ions into the wafer W, and supplies the high-frequency bias power to the stage 20 . The frequency of the high-frequency bias power is a frequency within a range of 400 kHz to 13.56 MHz, and is 3 MHz in one example. The integrator MU2 has a circuit for integrating the output impedance of the second high-frequency power supply LFS and the input impedance of the load side (the base 20 side).

On the base 20, a support member 18 is provided. In one embodiment, the support member 18 is an electrostatic chuck. The support member 18 attracts the wafer W by electrostatic force such as Coulomb force, and holds the wafer W. The support member 18 has the electrode E1 for electrostatic adsorption in the main body part made of ceramics. The electrode E1 is electrically connected to the DC power source 22 through the switch SW1.

On the top surface of the base 20 and around the support member 18 , a ring-shaped member is arranged so as to surround the wafer W. As shown in FIG. For example, on the top surface of the base 20 and around the support member 18, a focus ring FR is provided as a ring-shaped member. The focus ring FR is provided to improve the uniformity of plasma processing. The focus ring FR is formed of a material appropriately selected according to the plasma processing to be performed, for example, silicon or quartz.

Inside the base 20, a refrigerant flow path 24 is formed. The refrigerant is supplied to the refrigerant flow path 24 from a cooling unit provided outside the processing container 12 through the piping 26a. The refrigerant supplied to the refrigerant passage 24 is returned to the cooling unit via the piping 26b. In addition, the detailed structure of the mounting table 16 including the base 20 and the support member 18 will be described in detail later.

Inside the processing container 12, an upper electrode 30 is provided. The upper electrode 30 is arranged to face the base 20 above the mounting table 16 , and the base 20 and the upper electrode 30 are arranged to be substantially parallel to each other.

The upper electrode 30 is supported by the upper portion of the processing chamber 12 through the insulating shielding 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 with less Joule heat.

The electrode holder 36 is a member that supports the electrode plate 34 in a freely attachable and detachable manner, and can be made of a conductive material such as aluminum, for example. The electrode holder 36 may have a water-cooled structure. Inside the electrode holder 36, a gas diffusion chamber 36a is provided. The plurality of gas passage holes 36b extend downward from the gas diffusion chamber 36a and communicate with the gas discharge holes 34a. In addition, a gas introduction port 36c for introducing the process gas into the gas diffusion chamber 36a is formed in the electrode support 36, and the gas introduction port 36c is connected to the gas supply pipe 38. As shown in FIG.

The gas supply pipe 38 is connected to the gas source group 40 through the valve group 42 and the flow controller group 44 . The valve group 42 includes a plurality of on-off valves, and the flow controller group 44 includes a plurality of flow controllers such as mass flow controllers. In addition, the gas source group 40 includes gas sources for a plurality of gases necessary for plasma processing. The plurality of gas sources of the gas source group 40 are connected to the gas supply pipe 38 through corresponding on-off valves and corresponding mass flow controllers.

In the substrate processing apparatus 10 , one or more kinds of gas from selected one or more gas sources among the plurality of gas sources in 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 into 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 ground conductor 12 a is a substantially cylindrical ground conductor, and is provided to extend from the side wall of the processing container 12 to a position higher than the height position of the upper electrode 30 .

In addition, in the substrate processing apparatus 10 , a deposition baffle 46 is provided along the inner wall of the processing container 12 in a freely attachable and detachable manner. In addition, a deposition baffle 46 is also provided on the outer periphery of the support portion 14 . The deposition baffle 46 is a member for preventing etching by-products (deposits) from adhering to the processing chamber 12 , and can be formed by coating an aluminum material with ceramics such as Y ₂ O ₃ .

On the bottom side of the processing container 12 , an exhaust plate 48 is provided between the support portion 14 and the inner wall of the processing container 12 . The exhaust plate 48 can be made of, for example, an aluminum material coated with ceramics such as Y ₂ O ₃ . Below the exhaust plate 48 , an exhaust port 12 e is provided in the processing container 12 . The exhaust port 12e is connected to the exhaust device 50 through the exhaust pipe 52 . The exhaust device 50 includes a vacuum pump such as a turbomolecular pump, and can depressurize the inside of the processing chamber 12 to a desired degree of vacuum. In addition, a loading and unloading port 12 g of the wafer W is provided on the side wall of the processing container 12 , and the loading and unloading port 12 g can be 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 part of the substrate processing apparatus 10 . The operation of the substrate processing apparatus 10 is collectively controlled by the control unit 100 .

[Structure of Mounting Table] Next, the mounting table 16 will be described in detail. FIG. 3 is a plan view showing a mounting table according to an embodiment. The mounting table 16 as described above includes the support member 18 and the base 20 . The support member 18 has a main body portion 18m made of ceramics. The main body portion 18m has a roughly disc shape. The main body portion 18m is provided with a mounting area 18a and an outer peripheral area 18b. The placement area 18a is a substantially circular area in plan view. On the top surface of the placement area 18a, the wafer W can be placed. In addition, the diameter of the placement area 18a is approximately the same as the diameter of the wafer W, or slightly smaller than the diameter of the wafer W. As shown in FIG. The outer peripheral region 18b is a region surrounding the mounting region 18a, and extends in a substantially annular shape. In one embodiment, the top surface of the outer peripheral region 18b is located at a lower position than the top surface of the placement 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 adsorption in the mounting area 18a. The electrode E1 is connected to the DC power source 22 via the switch SW1 as described above.

In addition, in the placement area 18a, below the electrode E1, a plurality of heaters HT are provided. In one embodiment, the placement area 18a is divided into a plurality of divided areas, and heaters HT are provided in each divided area. For example, as shown in FIG. 3 , a plurality of heaters HT are provided in a circular area in the center of the placement area 18a and in a plurality of concentric annular areas surrounding the circular area. In addition, in each of the plurality of annular regions, the plurality of heaters HT are arranged in the circumferential direction. In addition, the division method of the division|segmentation area shown in FIG. 3 is only an example, and it is not limited to this. The placement area 18a may be divided into more divided areas. For example, the mounting area 18a may be divided into divided areas whose angular width becomes smaller and the width in the diameter direction becomes narrower as it approaches the outer periphery. The heater HT is individually connected to the heater power source HP shown in FIG. 2 through a wiring not shown in the figure provided in the outer peripheral portion of the base 20 . Individually adjusted electric power is supplied to each heater HT from the heater power supply HP. Thereby, the heat which each heater HT generate|occur|produces is individually controlled, and the temperature of the some divided area in the mounting area 18a is individually adjusted. At least one measurement point for measuring the CD of the wafer W is provided in the divided region where the heater HT is provided.

[Configuration of Control Unit] Next, the control unit 100 will be described in detail. FIG. 4 is a block diagram showing a schematic configuration of a control unit that controls a substrate processing apparatus according to an embodiment. The control unit 100 is provided with a communication interface 101 , a program controller 102 , a user interface 103 , and a memory unit 104 .

The communication interface 101 can communicate with the measurement device 11 through the network N, and can send and receive various data with the measurement device 11 . For example, the communication interface 101 receives the CD data sent by the measuring device 11 .

The program controller 102 includes a CPU (Central Processing Unit) and controls each part of the substrate processing apparatus 10 .

The user interface 103 is composed of a keyboard for the step manager to input commands for managing the substrate processing apparatus 10 , or a display for displaying and visualizing the operation status of the substrate processing apparatus 10 .

The memory unit 104 stores a control program (software) for realizing various processes performed by the substrate processing apparatus 10 under the control of the program controller 102, or a recipe in which processing condition data and the like are stored. In addition, the recipe of the control program or processing condition data, etc., can be used in a state stored in a computer-readable computer recording medium (for example, a hard disk, a CD such as a DVD, a floppy disk, a semiconductor memory, etc.), or the like, or It is used online from other devices such as real-time transmission through a dedicated loop.

The program controller 102 has an internal memory for storing programs or data, reads the control program stored in the memory unit 104, and executes processing of the read control program. The program controller 102 functions as various processing units by controlling the operation of the program. For example, the program 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. In addition, in the substrate processing apparatus 10 of the present embodiment, an example in which the program controller 102 has the functions of the generation unit 102a, the calculation unit 102b, the plasma control unit 102c, and the heater control unit 102d will be described. However, 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 a plurality of controllers, respectively.

In addition, in substrate processing such as plasma etching, it is desirable that the entire CD range (difference between the maximum value of CD and the minimum value of CD) of the wafer W is small, and the average value of CD is close to the target value. On the other hand, in the substrate processing, the progress of the processing varies depending on the temperature of the wafer W. FIG. For example, in plasma etching, the rate of progress of the etching varies depending on the temperature of the wafer W. Therefore, in the substrate processing apparatus 10 of the present embodiment, a prediction model for predicting the critical dimension of a predetermined measurement point of the wafer W using the temperature of each heater HT as a parameter is used to realize the overall CD of the wafer W. A state where the range is smaller and the average value of CD is close to the target value.

Here, the prediction model will be described. In the present embodiment, a description will be given of a prediction model in which the critical dimension of the measurement point is modeled as a linear function of the temperature of each heater HT.

In the vicinity of the boundary between each divided area and the adjacent divided area, the temperature is also changed due to the influence of the adjacent divided area. When the influence of the temperature of the heater HT adjacent to the divided region is added to the measurement point, the temperature of each measurement point is expressed by the following formula (1) using the temperature T of the heater HT as a parameter.

[Formula 1]

Here, i is the number of the divided region including the measurement point and in which the heater HT is installed. j is the number of the measurement point included in the divided area in which the heater HT is installed. T _i represents the temperature of the divided region numbered i. δT _i,j represents the temperature difference between the temperature of the measurement point j and the temperature of Ti in the divided area of the number _i . This temperature difference occurs due to the influence of heat from adjacent divided regions. δT _i,j also varies depending on the distance between the measurement point and the adjacent divided region.

δT _i,j is obtained as follows. The temperature distribution of the divided regions was measured by infrared thermography as a state in which the temperatures of the heaters HT in the adjacent two divided regions were changed. The temperature distribution of the divided regions may be obtained at least once in advance. In addition, the temperature distribution of the divided regions is not necessarily measured by the substrate processing apparatus 10 , and may be measured by a measurement mounting table having the same structure as the mounting table 16 . For example, measurement may be performed using a mounting table for measurement having the same components as the mounting table 16 . FIG. 5 is a diagram showing an example of a temperature distribution. In the mounting table 16 shown in FIG. 5 , the mounting region 18a on which the wafer W is mounted is divided into divided regions 19a, 19b, 19c, and 19d. In FIG. 5(A), the image of the infrared thermography when the temperature of the heater HT is changed in the inner divided area 19a and divided areas 19b, 19c, and 19d is shown. In FIG. 5(B), the boundary line of the divided regions 19a and 19b is zero, and the curve which shows the temperature change with respect to the distance d from the boundary line is shown. In the example of FIG. 5(B), the temperature of the divided region 19a is 29.5°C, and the temperatures of the divided regions 19b and 19c are 34°C. As shown in FIG. 5(B) , the temperature in the vicinity of the boundary between the divided area 19b and the divided area 19a is affected by the divided area 19a, and is not 34°C, and the temperature varies depending on the distance from the divided area 19a .

For example, when two adjacent divided areas 19 are set as divided area 19-1 and divided area 19-2, the temperature of divided area 19-1 is set to T _1-1 , and the temperature of divided area 19-2 is set to When T _2-1 is used, the temperature T at the position of the distance d from the boundary line of the divided region 19-2 is represented by an approximate formula as shown in the following formula (2).

[Equation 2]

Here, λ is a constant used to approximate the temperature change curve. For example, when the temperature change curve of FIG. 5(B) is approximated, λ is 7.2 mm.

When δT _i,j is represented by the formula (2), the formula (1) is represented by the following formula (3).

[Equation 3]

Here, k is the number of the division area adjacent to the i-th division area. d _i,j,k is the distance between the j-th measurement point of the i-th divided area and the adjacent k-th divided area. Since the position of the measurement point is determined in advance, d _i,j,k can be determined in advance, respectively. λ _i,j,k is a constant representing the influence of the adjacent k-th divided area on the j-th measurement point of the i-th divided area. When the influence of adjacent divided regions is considered to be the same, λ _i,j,k can also be considered to be all the same value. For example, when the measurement result of FIG. 5(B) is used, λ _i,j,k is all 7.2 mm.

FIG. 6 is a diagram illustrating the relationship of the divided regions. In FIG. 6, divided regions 19l to 19t are shown. The divided area 19p is adjacent to the divided areas 191 to 19o and 19s. In addition, the measurement point 21 is included in the divided area 19p. When the number of the divided region 19p is i, the number of the divided regions 191 to 19o and 19s is k. Note that d _i,j,k is the distance between the measurement point 21 indicated by the arrow in FIG. 6 and the divided regions 191 to 19o and 19s.

Next, in order to obtain data for generating a prediction model, the substrate processing apparatus 10 controls each heater HT so that the temperature of each divided region is at several levels, exchanges the wafers W at each temperature, and separates the wafers W individually. The actual plasma etching is carried out. For example, the substrate processing apparatus 10 controls each heater HT to three or more temperatures, exchanges the wafers W at the respective temperatures, and individually performs the actually performed plasma etching. As an example, the substrate processing apparatus 10 performs plasma etching on the wafer W with each heater HT at 50°C. Then, the substrate processing apparatus 10 performs plasma etching on the wafer W with each heater HT at 55°C. Then, the substrate processing apparatus 10 performs plasma etching on the wafer W with each heater HT at 45°C. In addition, when obtaining data for generating a prediction model, the temperature of each segment does not necessarily have to be the same in all segments. That is, a part of the divided regions may have a temperature different from that of the other divided regions. For example, the temperature of the divided region near the center of the placement region 18a may be different from the temperature of the divided region near the outer periphery of the placement region 18a.

Each wafer W subjected to plasma etching at each temperature is transported to the measurement apparatus 11 , respectively. The measurement device 11 measures the CD of the measurement point with respect to each of the transferred wafers W using a predetermined position as the measurement point. For example, the measuring device 11 measures the CD of each measurement point of each wafer W in which plasma etching was performed with each heater HT at three temperatures of 45°C, 50°C, and 55°C. The measurement device 11 transmits the data of the CD of each measurement point measured to the substrate processing device 10 .

When the CD of the measurement point is predicted as a linear function of the temperature T of each heater HT, the CD of each measurement point is expressed by the following formula (4-1) with the temperature T of the heater HT as a parameter.

[Equation 4]

Here, i is the number of the divided region including the measurement point and in which the heater HT is installed. For example, the number i is sequentially assigned to the divided area in which the heater HT is installed. j is the number of the measurement point included in the divided area in which the heater HT is installed. For example, the number j is sequentially assigned to the measurement point for each divided area in which the heater HT is installed. CD _i,j is a value indicating the CD of the measurement point of number j included in the divided region of number i. T _i represents the temperature of the divided region numbered i. T _i,j represents the temperature of the measurement point of the number j of the divided area of the number i. A _{11_i,j} is a coefficient of a linear function for obtaining the value of the CD of the measurement point of the number j included in the divided region of the number i from the temperature T _i,j . T _{i_a} represents the average temperature in which the temperatures of the three or more divided regions of the CD number i were measured. For example, when CD is measured at three temperatures of 45°C, 50°C, and 55°C, _{Ti_a} is 50°C. T _{i,j_a} represents the average temperature of three or more temperatures in which the CD of the measurement point of the number j of the divided area of the number i was measured. A _{10_i,j} represents the average value of CDs measured at three or more temperatures of the measurement points of number j included in the divided area of number i, respectively.

When the formula (4-1) is expressed in the form of the formula (4-2), the temperature τ _l is expressed in the form of the following formula (5-2), and a _i,j,l is expressed in the following formula (5- When expressed in the form of 3), the formula (4-1) is expressed in the form of the following formula (5-1).

[Equation 5]

Here, 1 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 the prediction model, the substrate processing apparatus 10 controls each heater HT so that the temperature of each divided region is at several levels, exchanges the wafer W at each temperature, and performs the actual plasma treatment individually. etching. For example, the substrate processing apparatus 10 controls each heater HT to three or more temperatures, exchanges the wafers W at the respective temperatures, and individually performs the actually performed plasma etching. As an example, the substrate processing apparatus 10 performs the plasma etching process on the wafer W with each heater HT at 50°C. Then, the substrate processing apparatus 10 performs the plasma etching process on the wafer W with each heater HT at 55°C. Then, the substrate processing apparatus 10 performs the plasma etching process on the wafer W with each heater HT at 45°C.

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

The generation unit 102a generates a prediction model based on the received CD data. For example, the generation unit 102 a sets the heaters HT at three temperatures of 45° C., 50° C., and 55° C., based on the information received from the measurement device 11 , and the measurement points of the respective wafers W that have undergone the plasma etching process. The data of CD are fitted with the CD at each measurement point and the temperature of each heater HT to obtain the value of the coefficient A _{11_i,j} .

After the value of the coefficient A _{11_i,j} is obtained, the coefficient a _i,j,l can be obtained according to the above formula (5-3), and the CD _i can be calculated according to the temperature τ _l using the above formula (5-1) _,j .

The generation unit 102a obtains the coefficient a _i,j,l by substituting the value of the obtained coefficient A _{11_i,j} into the formula (5-3), and generates the coefficient a i,j,l into which the obtained coefficient a _i,j,l is substituted The formula (5-1) is used as the prediction model.

The calculating part 102b calculates the target temperature of the heater HT of each division|segmentation area|region whose CD of a measuring point satisfies a predetermined|prescribed condition using the prediction model generated by the generating part 102a. For example, the calculation unit 102b calculates the temperature of the heater HT in each divided area where the sum of the squares of the errors of the CD of each measurement point with respect to the target value μ is the smallest, using the prediction model.

The method of calculating the temperature of the heater HT in each divided region in which the sum of squares of the errors is the smallest will be specifically described.

The above-mentioned formula (5-1) is represented by the following formula (6).

[Equation 6]

Here, m is a number for identifying the measurement point. For example, when there are 400 measurement points, m is 1 to 400. In formula (5-1), the measurement points are sequentially numbered in each divided area, but in formula (6), the measurement points in all divided areas are sequentially assigned the number m. n is the number of the divided area in which the heater HT is installed. CD _m , corresponding to CD _i,j , is the CD representing the measurement point of number m. τ _n , corresponding to τ _l , represents the temperature of the heater HT in the divided area numbered n. a _m,n , corresponding to a _i,j,l , represent coefficients. A _{10_m} , corresponding to A _{10_i,j} , represents the average value of CDs measured at three or more temperatures at the measurement point number m.

In substrate processing such as plasma etching, it is preferable that the CD range of the entire surface of the wafer W is small, and the average value of the CD is close to the target value as the target size. Therefore, for all the measurement points, the temperature of the heater HT in each divided region where CD _m is approximately the target value μ (CDm≒μ) is set as T ^* _n . According to the above-mentioned formula (5-2), τ ^* _n is one having the relationship of the following formula (7).

[Equation 7]

The CD of each measurement point may have an error with respect to the target value μ due to the difference of the CD of each measurement point before the substrate processing, or the influence of the substrate processing. Therefore, the CD _m of each measurement point when the temperature of the heater HT of each divided area is set to τ ^* _n is expressed by the following formula (8).

[Equation 8]

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

From Equation (8), the sum of squares of errors at each measurement point is expressed by the following Equation (9).

[Equation 9]

The point at which the sum of squares of the errors represented by the formula (9) becomes the minimum is the point where the minimum value is obtained. At the minimum value, the formula (9) satisfies the following formula (10-1), and according to the formula (10-1), the formula (10-2) is satisfied.

[Equation 10]

When x _{l, n} is represented by the formula (11-2) and y _l is represented by the formula (11-3), the formula (10-2) is represented by the following formula (11-1). For example, when the number of measurement points is 400, in the formula (11-2) and the formula (11-3), m is the sum of 1 to 400.

[Equation 11]

Here, 1 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) is expressed by the calculation of a matrix as in the following formula (12).

[Equation 12]

The matrix represented by the formula (12) can be converted into the matrix of the following formula (13) by obtaining the inverse matrix.

[Equation 13]

The x _l,n of the matrix can be calculated by substituting a m, _l and a _i,j,l corresponding to 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 calculates the temperature τ ^* _n of the heater HT in each divided region where the sum of the squares of the errors is the smallest by solving the matrix of the equation (13).

In addition, even if the sum of squares of errors is the smallest, the range of CD may not be small. FIG. 7 is a diagram illustrating an example of the relationship between the squared sum of errors and the range. The horizontal axis of FIG. 7 is the number of the measurement point. The vertical axis of FIG. 7 is the CD of 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 errors is to be minimized, the overall error of each measurement point may be reduced. Therefore, for example, as shown in FIG. 7 , even if one measurement point has a large error with respect to the target value μ, the sum of squares of the errors is still small if many other measurement points have small errors with respect to the target value μ. On the other hand, the range of CD is the difference between the maximum value of CD and the minimum value of CD. In the case of the example of FIG. 7, the range of CD is not small.

However, there is a strong positive correlation between the range of CD and the dispersion of errors. It is considered that the range of CD is the minimum temperature of the heater HT in each segment, and is located around the temperature τ ^* _n of the heater HT in each segment where the sum of the squares of the errors is the smallest.

Therefore, the calculation unit 102b calculates the CD of each measurement point by changing the temperature Tn of the heater HT in each divided area, using the temperature τ ^* _n of the heater HT in each divided area _where the sum of the squares of the errors is the smallest as a reference. The range is the minimum target temperature of the heater HT of each divided area. For example, the calculation unit 102b uses the temperature τ ^* _n of the heater HT in each divided area as a reference, changes the temperature of the heater HT individually by a predetermined temperature, and calculates the CD of each measurement point, and specifies the range of the CD. It is the combination of the temperatures of the heaters HT in each divided area with the smallest value. The predetermined temperature may be a fixed value, may be changed according to processing conditions, or may be set from an external device. In this embodiment, the predetermined temperature is set to 1 degree. The calculation unit 102b uses a value obtained by adding random numbers to the temperatures of the heaters HT in each divided area individually for the specified combination of the temperatures of the heaters HT in each divided area, for example, using a GRG method (Generalized Reduced Value). Gradient method, generalized approximate gradient method), calculates the target temperature of the heater HT of each divided area in which the range of CD is the smallest. In addition, the calculation unit 102b may repeatedly randomize the temperature of the heater HT in each divided area in a temperature range smaller than the predetermined temperature, or in accordance with a predetermined temperature, for the specified combination of the temperatures of the heaters HT in each divided area. The CD of each measurement point is calculated by changing the rule, and further, the target temperature of the heater HT of each divided area in which the range of CD is the smallest is calculated.

The plasma control unit 102c controls various parts of the substrate processing apparatus 10 to control plasma processing. For example, the plasma control unit 102c reads a recipe and the like corresponding to the plasma etching performed from the memory unit 104, and controls each part of the substrate processing apparatus 10 based on the read recipe and the like.

The heater control unit 102d controls the heater HT of each divided area to form a calculation unit 102b when performing plasma etching on the wafer W placed in the placement area 18a of the placement table 16 under the control of the plasma control unit 102c Calculated target temperature. For example, the heater control unit 102d controls the heater power supply HP, and supplies electric power corresponding to each target temperature to each heater HT.

The wafer W on which the plasma etching has been performed is transferred to the measurement apparatus 11 . The measuring apparatus 11 measures the CD of the measurement point of the transferred wafer W, and transmits the data of the measured CD to the substrate processing apparatus 10 .

The calculation unit 102b determines whether the CD range is within the allowable range based on the CD data received from the measuring device 11, and corrects the prediction model when the CD range is not within the allowable range. For example, the calculation unit 102b adds the value of CD-target value μ of each measurement point to the function of each measurement point of each prediction model, and calculates again the temperature τ ^* of the heater HT in each segment where the sum of the squares of the errors is the smallest _n . Then, the calculation unit 102b calculates the CD of each measurement point by changing the temperature T _n of the heater HT in each divided area using the temperature τ ^* _n of the heater HT in each divided area where the sum of the squares of the errors is the smallest as a reference. The range is the minimum target temperature of the heater HT of each divided area. In the substrate processing apparatus 10 of the present embodiment, after the wafer W is subjected to plasma etching at the calculated target temperature of the heater HT of each divided region, the CD range of the measurement point of the wafer W is not within the allowable range When it is within the value, the reproduction of the prediction model is carried out.

[Flow of Temperature Control] Next, a temperature control method using the substrate processing apparatus 10 of the first embodiment will be described. FIG. 8 is a flowchart showing an example of the flow of the temperature control method of the first embodiment.

The generation unit 102a initializes the error flag EF to 0 (step S10). The generation unit 102a uses the temperature of each heater HT as a parameter, adds the influence of the temperature of the heater HT in the adjacent divided area corresponding to the distance between the measurement point and the divided area adjacent to the divided area including the measurement point, and obtains A function of the temperature at the measurement point is predicted (step S11). In the present embodiment, the generation unit 102a obtains a function that predicts 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 Expression (5-1), Expression (5-2), and Expression (5-3).

The generation unit 102a acquires data for measuring the CDs of the measurement points of the wafer W where the heaters HT of the respective divided regions are positioned at several levels and the plasma etching has been performed (step S12). For example, the substrate processing apparatus 10 controls each heater HT so that the temperature of each divided region is at several levels, exchanges the wafer W at each temperature, and performs the actually performed plasma etching individually. Each wafer W subjected to plasma etching at each temperature is moved to the measurement device 11 , and the CD of the measurement point is measured by the measurement device 11 with a predetermined position of the wafer W as a measurement point. The measurement device 11 transmits the data of the CD of each measurement point measured to the substrate processing device 10 . The generation unit 102a obtains the data of the measured CD of each measurement point from the measurement device 11, and obtains the measurement data of the wafer W that has been subjected to plasma etching with the heater HT of each divided area at several levels. The CD data of the measurement point.

The generation unit 102a generates a prediction model based on the acquired data (step S13). For example, the generation unit 102a fits the obtained function with the measured CD of each measuring point and the temperature of each heater HT, and obtains a function that predicts the CD of the measuring point from the temperature of each heater HT as a predictive model.

The calculation unit 102b initializes the count value i to 1 (step S14). Then, the calculation unit 102b uses the generated prediction model to calculate the temperature τ ^* _n of the heater HT in each divided area where the sum of squares of the errors of the CD at each measurement point with respect to the target value μ is the smallest (step S15).

The calculation unit 102b calculates the CD of each measurement point by changing the temperature of the heater HT by a predetermined temperature (for example, 1 degree), using the temperature τ ^* _n of the heater HT in each divided area as a reference, respectively, and specifies the value. The range of CD is the combination of the temperatures of the heaters HT in the respective divided regions with the smallest value (step S16).

The calculation unit 102b separately obtains and adds a random number to the temperature of the heater HT in each of the specified divided regions (step S17). The calculating part 102b calculates the temperature of the heater HT of each division|segmentation area|region in which the range of CD is the smallest, using the value added with the random number as an initial value, for example, by the GRG method (step S18).

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

On the other hand, when the average value of CD is smaller than the upper limit of the required specification (step S19: Yes), the calculation unit 102b determines whether the average value of CD is larger than the lower limit of the required specification (step S21). When the average value of 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 stores the average value of CD, the range of CD, and the temperature of the heater HT in each divided area data (step S23).

The calculation unit 102b determines whether or not the count value i is smaller than the predetermined number of times N of processing (step S24). When the count value i is smaller than the predetermined number of processing times N (step S24: Yes), the calculation unit 102b increments the count value i by 1 (step S25), and proceeds to the above-described step S15.

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

The heater control unit 102d controls the target temperature used for forming the heater HT in each divided region when the wafer W placed in the placement region 18a of the placement table 16 is subjected to plasma etching (step S27).

The wafer W on which the plasma etching has been performed is transferred to the measurement apparatus 11 . The measuring apparatus 11 measures the CD of the measurement point of the transferred wafer W, and transmits the data of the measured CD to the substrate processing apparatus 10 .

The calculation unit 102b determines whether or not the range of the CD is within the allowable range based on the data of the CD received from the measuring device 11 (step S28). When the range of CD is not within the allowable range (step S28: No), the calculation unit 102b determines whether or not 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 temperature of the CD and the heater HT (step S30) as data for generating the prediction model, and shifts the data again. Going to step S13, based on the measured data of the temperature of the CD and the heater HT, and the data obtained in step S12, a prediction model is generated again.

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

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

The calculation unit 102b determines whether or not the CD range is within the allowable range based on the CD data received from the measuring device 11 after a predetermined period of time (step S33). When the range of CD is within the allowable range (step S33: Yes), the process proceeds to step S32 again, and the process waiting for a predetermined period is executed.

On the other hand, when the range of CD 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 executes correction of the prediction model (step S35). For example, the calculation unit 102b performs correction of the function of adding the value of CD-target value μ of each measurement point to each measurement point of each prediction model. Then, the calculation part 102b proceeds to step S14 again, and calculates the target temperature again.

On the other hand, when the error flag EF is not 0 (step S29: No), it is when the range of the corrected prediction model CD is not within the allowable range. At this time, since the generation unit 102a cannot generate an appropriate prediction model based on the acquired data, an error is output (step S36), and the process ends. For example, the generation unit 102a outputs to the user interface 103 a message "please obtain and correct the data of the measurement points of the wafer W where the heater HT of each divided area is at several levels and plasma etching is performed", and end processing.

When an error is output, the step manager controls each heater HT of the substrate processing apparatus 10 so that the temperature of each divided area is at several levels, exchanges the wafer W at each temperature, and implements the actual implementation individually. The plasma etching is carried out again, and the data acquisition for the prediction model generation is carried out again, and then the temperature control method of this embodiment is carried out.

In this way, the substrate processing apparatus 10 according to the first embodiment uses the temperature of the heater HT of each divided area as a parameter, and adds the distance corresponding to the measurement point and the divided area adjacent to the divided area including the measurement point. The influence of the temperature of the heater HT adjacent to the divided region is calculated as a prediction model for predicting the CD at a predetermined measurement point of the wafer W when plasma etching is performed on the wafer W placed on the mounting surface of the mounting table 16 . The CD of the measurement point satisfies the target temperature of the heater HT in each divided area where the predetermined condition is satisfied. The substrate processing apparatus 10 controls the heaters HT of the respective divided regions to achieve a target temperature when the wafer W placed on the placement surface is subjected to plasma etching. As a result, the substrate processing apparatus 10 can control the temperature of the heater HT in each divided area so that the CD of the measurement point of the wafer W satisfies the predetermined condition.

In addition, the substrate processing apparatus 10 of the first embodiment uses a prediction model to calculate the heater temperature HT of each divided area in which the sum of squares of the errors of the CD of each measurement point with respect to the target size is the smallest. The substrate processing apparatus 10 changes the temperature of the heater HT in each divided area based on the calculated temperature of each divided area, and calculates the temperature of each divided area where the difference between the maximum value and the minimum value of CD at each measurement point is the smallest. The target temperature of the heater. As a result, the substrate processing apparatus 10 can accurately calculate the temperature of the heater HT for improving the CD uniformity of the wafer W.

In addition, in the substrate processing apparatus 10 of the first embodiment, based on data obtained by measuring the CD at the measurement point when the temperature of the heater HT in each divided region is controlled to three or more and the wafer W is subjected to plasma etching, Generate predictive models. The substrate processing apparatus 10 uses the generated prediction model to calculate the target temperature of the heater HT in each divided area where the CD of the measurement point satisfies the predetermined condition. As a result, the substrate processing apparatus 10 can generate a prediction model capable of accurately predicting the CD of the measurement point.

(Second Embodiment) Next, a second embodiment will be described. The substrate processing system 1 and the substrate processing apparatus 10 of the second embodiment have the same structures as those of the substrate processing system 1 and the substrate processing apparatus 10 of the first embodiment shown in FIGS. 1 to 4 , so the description is omitted.

Next, the prediction model of the second embodiment will be described. The relationship of the following formula (14) exists between the temperature T of each heater HT and the CD at the measurement point.

[Equation 14]

Here, A' is a coefficient of an 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 the magnitude of the physical adsorption energy. Specifically, it is about B´≒0.25[eV]×1.7E4[K/eV]=4.3E3K.

CD is represented by the formula (15) according to the formula (14).

[Equation 15]

Here, CD ₀ is a constant term of CD.

exp(B´/T) of Equation (15), when the temperature T is represented by the difference τ from the average temperature T _a of three or more temperatures for which CD is measured as in the following Equation (16-1), it is expressed as It is represented by the following formula (16-2).

[Equation 16]

In the formula (16-2), when x is represented by the following formula (17-2), it is represented by the following formula (17-1).

[Equation 17]

The formula (17-1) can be approximated by the following formula (18-1), and it can be expressed by the formula (18-2).

[Equation 18]

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

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

[Equation 19]

Therefore, the formula (15) is represented by the following formula (20) when the formula (19) is used for exp(B´/T).

[Expression 20]

In addition, when more precision is required, a larger term than the quadratic term of equation (18-2) can also be used for exp(B´/T) to approximate it. Alternatively, the exponential function may be used as exp(B´/T) as it is.

In formula (20), A ₂₀ is represented by the following formula (21-2), A ₂₁ is represented by the following formula (21-3), and A ₂₂ is represented by the following formula (21-4) When it is expressed in the form of , it is expressed in the form of the following formula (21-1).

[Equation 21]

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

Equation (21-1) is expressed as the following Equation (22) when expressed as a formula for calculating CD _i,j of each measurement point of each divided region in which the heater HT is provided.

[Equation 22]

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

The generation unit 102a generates a first prediction model in which the CD at the measurement point is modeled as a linear function of the temperature of the heater HT, based on the received CD data. For example, the generation unit 102a, as in the first embodiment, has been subjected to plasma etching with each heater HT set to three temperatures of 45°C, 50°C, and 55°C based on the information received from the measuring device 11 . The data of the CD of the measurement point of each wafer W are fitted with the CD of each measurement point and the temperature of each heater HT, and the function of predicting the CD of the measurement point as a linear function of the temperature T of each heater HT is obtained as 1st prediction model. For example, the generation unit 102a obtains Equation (5-1), Equation (5-2), and Equation (5-3) as the first prediction model.

In addition, the generation unit 102a generates the CD of the measurement point as a function of the quadratic or higher of the temperature of the heater HT, or the sum of the exponential function of the reciprocal of the absolute temperature of the heater and a constant based on the received CD data Modeled second prediction model. For example, the generation unit 102 a sets the heaters HT at three temperatures of 45° C., 50° C., and 55° C., based on the information received from the measurement device 11 , and the measurement points of the respective wafers W that have undergone the plasma etching process. The data of CD were fitted by the CD of each measuring point and the temperature of each heater HT, and the values of the coefficients A _{20_i,j} , A _{21_i,j} , and A _{22_i,j} were obtained.

After the coefficients A _{20_i,j} , A _{21_i,j} , and A _{22_i,j} are obtained, the CD _i,j of the temperature T _l can be calculated according to the above formula (16-1) and the above formula (22).

In addition, the generation unit 102a may perform fitting with an equation that approximates exp(B´/T) using a term larger than the quadratic term of equation (18-2), when more preciseness is required, and generates 2nd prediction model. In addition, the generation unit 102a may use the exponential function as exp(B'/T) as it is, and perform fitting to generate the second prediction model.

The calculating part 102b calculates the target temperature of the heater HT of each divided area|region whose CD of a measuring point satisfies predetermined conditions using the 1st prediction model and the 2nd prediction model generated by the generation part 102a. For example, the calculation unit 102b uses the first prediction model to calculate the temperature τ of the heater HT in each divided area where the sum of the squares of the errors of the CDs of the measurement points with respect to the target value μ is the smallest, as in the first embodiment. ^* _n .

Then, the calculation unit 102b changes the temperature of the heater HT in each divided area using the calculated temperature of the heater HT in each divided area as a reference, and calculates the maximum value of the critical dimension of each measurement point and the The difference between the minimum values is the target temperature of the heater in each of the smallest divided areas. For example, the calculation unit 102b uses the temperature τ ^* _n of the heater HT in each divided area as a reference, and changes the temperature T _n of the heater HT in each divided area by using the above-mentioned formula (3 ) and Equation (22) to calculate the target temperature of the heater HT in each divided area where the range of CD at each measurement point is the smallest. For example, the calculation unit 102b uses the temperature τ ^* _n of the heater HT in each divided area as a reference, changes the temperature of the heater HT individually by a predetermined temperature, and calculates the CD of each measurement point, and specifies the range of the CD. It is the combination of the temperatures of the heaters HT in each divided area with the smallest value. Then, the calculation unit 102b sets the value obtained by adding random numbers to the temperature of the heater HT in each divided area individually for the specified combination of the temperatures of the heaters HT in each divided area. For example, by the GRG method, The target temperature of the heater HT of each divided area in which the range of CD is the smallest is calculated. In addition, the calculation unit 102b may repeatedly randomize the temperature of the heater HT in each divided area in a temperature range smaller than the predetermined temperature, or in accordance with a predetermined temperature, for the specified combination of the temperatures of the heaters HT in each divided area. The CD of each measurement point is calculated by changing the rule, and further, the target temperature of the heater HT of each divided area in which the range of CD is the smallest is calculated.

[Flow of Temperature Control] Next, a temperature control method using the substrate processing apparatus 10 of the second embodiment will be described. FIG. 9 is a flowchart showing an example of the flow of the temperature control method of the second embodiment. The temperature control method of the second embodiment is similar to the temperature control method of the first embodiment shown in FIG. 8 in that part of the processing is the same, so the same processing will be given the same symbol and the description will be omitted. The different processing sections are explained.

The generation unit 102a generates a first prediction model that models the CD at the measurement point as a linear function of the temperature of the heater HT based on the acquired data, and generates a CD at the measurement point as a quadratic or more of the temperature of the heater HT. function, or, a second prediction model in which the sum of the exponential function and the constant of the reciprocal of the absolute temperature of the heater is modeled (step S13a). For example, the generation unit 102a fits the obtained function with the measured CD of each measuring point and the temperature of each heater HT, and obtains a linear function prediction measurement by the temperature T of each heater HT, respectively. A function of the CD of the point, and a function of predicting the CD of the measurement point as a quadratic function of the temperature T of each heater HT.

The calculation unit 102b calculates the temperature τ ^* _n of the heater HT in each divided region where the sum of the squares of the errors of the CDs at each measurement point with respect to the target value μ is the smallest using the generated first prediction model (step S15a).

The calculation unit 102b uses the calculated temperature τ ^* _n of the heater HT in each divided area as a reference, and uses the second prediction model to individually change the temperature of the heater HT by a predetermined temperature (for example, 1 degree) by a predetermined temperature (for example, 1 degree). The CD of each measurement point is specified, and the combination of the temperatures of the heaters HT in each of the divided regions in which the range of the CD is the smallest is specified (step S16a).

The calculation unit 102b calculates the temperature of the heater HT in each divided region where the range of CD is the smallest by using the second prediction model, for example, the GRG method, using the random number added as the initial value (step S18a).

In this way, the substrate processing apparatus 10 of the second embodiment generates the first prediction model in which the CD of the measurement point is modeled by a linear function of the temperature of the heater HT. In addition, the substrate processing apparatus 10 generates a second prediction model in which the CD at the measurement point is modeled by a quadratic function of the temperature of the heater HT. Since the second prediction model is modeled by a quadratic function, CD can be predicted more accurately than the first prediction model. The substrate processing apparatus 10 uses the first prediction model to calculate the temperature of the heater HT in each of the divided regions where the sum of squares of errors in CD is the smallest. The second prediction model may not be able to calculate the temperature of the heater HT in each of the divided regions where the sum of squares of the errors is the smallest. Therefore, the substrate processing apparatus 10 uses the first prediction model to calculate the temperature of the heater HT in each of the divided regions where the sum of the squares of the errors is the smallest. The substrate processing apparatus 10 changes the temperature HT of the heater in each divided area using the calculated temperature of each divided area as a reference, and uses the second prediction model to calculate the difference between the maximum value and the minimum value of CD at each measurement point to be the smallest The target temperature of the heater HT for each divided area. Thereby, the substrate processing apparatus 10 can more accurately calculate the temperature of the heater HT which improves the uniformity of the CD of the wafer W, compared to the case where the target temperature of the heater HT is calculated using the first prediction model.

(3rd Embodiment) Next, the 3rd Embodiment is demonstrated. The substrate processing system 1 of the third embodiment has the same structure as that of the substrate processing system 1 of the first embodiment and the second embodiment shown in FIG. 1 , so the description is omitted.

The structure of the substrate processing apparatus 10 of the third embodiment will be described. FIG. 10 is a diagram schematically showing a substrate processing apparatus according to a third embodiment. The substrate processing apparatus of the third embodiment has a part of the same structure as the substrate processing apparatus 10 of the first embodiment and the second embodiment shown in FIG. Symbols are omitted, and descriptions are omitted, and different parts are mainly described.

The substrate processing apparatus 10 is provided with a first stage 116 in the processing container 12 . The top surface of the first stage 116 is formed in a roughly disk shape having a size approximately the same as that of the wafer W. As shown in FIG. The first mounting table 116 corresponds to the mounting table 16 shown in FIG. 2 , and includes the support member 18 and the base 20 .

In addition, in the substrate processing apparatus 10 , the second mounting table 120 is provided around the periphery along the outer peripheral surface of the first mounting table 116 . The second mounting table 120 is formed into 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 coaxially with the first mounting table 116 . The upper surface of the second mounting table 120 is a mounting surface 120 a on which the annular member arranged so as to surround the wafer W is mounted. In this embodiment, the annular focus ring FR is placed on the placement surface 120a as an annular member.

The second stage 120 includes a base 121 and a focus ring heater 122 . The base 121 is made of, for example, aluminum or the like on which an anodized film is formed. The base 121 is supported by the support unit 14 . The focus ring heater 122 is supported by the base 121 . The top surface of the focus ring heater 122 is a flat annular shape, and the top surface is the mounting surface 120a on which the focus ring FR is mounted. The focus ring heater 122 has a heater HT2 and an insulator 123 . The heater HT2 is provided inside the insulator 123 and is contained in the insulator 123 .

FIG. 11 is a plan view showing the first stage and the second stage of the third embodiment. The first mounting table 116 as described above has a top surface formed in a roughly disk shape having a size approximately the same as that of the wafer W, and a mounting area 18a is provided. The placement area 18a is a substantially circular area in plan view. On the top surface of the placement area 18a, the wafer W can be placed. The second mounting table 120 is formed in a substantially cylindrical shape so as to surround the first mounting table 116, and an outer peripheral region 18b is provided. The outer peripheral region 18b is an annular region in plan view. On the top surface of the outer peripheral area 18b, the focus ring FR can be placed.

The placement area 18a is divided into a plurality of divided areas, as in the first embodiment and the second embodiment, and heater HT1 is provided in each divided area. The heater HT1 corresponds to the heater HT shown in FIG. 2 .

The outer peripheral area 18b is also divided into a plurality of divided areas, and heater HT2 is provided in each divided area. For example, as shown in FIG. 11, the outer peripheral area 18b is divided into a plurality of divided areas in the circumferential direction, and heater HT2 is provided in each divided area. In addition, the division method of the division area shown in FIG. 11 is only an example, and it is not limited to this. The outer peripheral area 18b may also be divided into more divided areas. For example, the outer peripheral region 18b may be divided into divided regions whose angular width becomes smaller and the diameter in the diameter direction becomes narrower as it approaches the outer periphery.

The heater HT1 and the heater HT2 are individually connected to the heater power source HP shown in FIG. 10 through wiring not shown in the figure. The individually adjusted electric power is supplied from the heater power supply HP to each heater HT1 and each heater HT2.

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 structure as the control unit 100 of the first embodiment and the second embodiment shown in FIG. 4 , and is provided with a communication interface 101 , a program controller 102 , a user interface 103 , and a memory unit. 104.

The program controller 102 functions as various processing units by controlling the operation of the program. For example, the program 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.

In addition, in substrate processing such as plasma etching, when the heater HT2 is provided on the second stage 120 to control the temperature of the focus ring FR as in the substrate processing apparatus 10 of the present embodiment, the outer periphery of the wafer W is near the outer periphery. The progress of the treatment will also vary due to the temperature of the heater HT2. For example, in plasma etching, when the temperature of the heater HT2 is increased, the temperature of the focus ring FR increases. Then, in the plasma etching, when the temperature of the focus ring FR rises, "the plasma is consumed in the vicinity of the upper part of the focus ring FR, the concentration of the plasma in the vicinity of the outer periphery of the wafer W is reduced, and the wafer W is reduced. The phenomenon that etching progresses in the vicinity of the outer periphery is slowed down.

In this way, in plasma etching, when the temperature of the wafer W increases, the etching progresses faster, but when the temperature of the focus ring FR increases, on the contrary, the etching progresses in the vicinity of the outer periphery of the wafer W. slow down.

Therefore, in the substrate processing apparatus 10 of the present embodiment, the temperature of each heater HT1 and each heater HT2 is used as a parameter, the range for realizing the CD of the entire wafer W is smaller, and the average value of the CD is close to The state of the target value.

Here, the prediction model will be described. When the influence of the temperature of the heater HT1 and the heater HT2 is added, the CD of the measurement point has the relationship of the following formula (23).

[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 . The formula used for the prediction of CD ₀ corresponds to the above-mentioned formula (5-1). T _FR is the temperature of the heater HT2 of the FR part of the focus ring. ∂CD/∂T _FR ·ΔT _FR is a term (model part) that predicts the influence of the temperature of the heater HT2 in the focus ring FR part with respect to CD.

When the influence of the temperature of the heater HT1 of the other divided area is added, when the temperature T of the measuring point of CD is located in the vicinity of the average temperature T _a of the three or more temperatures in which the CD was measured, as described above, It can be approximated by a quadratic function of τ as shown in equation (21-1). Therefore, if the influence of the temperature of the heater HT2 is further added, the temperature T at the measurement point of CD is located in the vicinity of the average temperature T _a of the three or more temperatures measured for CD, and the temperature T _FR of the heater HT2 is located at In the case of the vicinity of the average temperature T _{FR — a} of the heater HT2 where CD was 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 in the following formula (24-2).

[Equation 24]

Here, τ is the difference between the temperature T at the measurement point and the average temperature Ta, as represented by the above-mentioned formula (16-1 ₎ . ξ is a temperature expressed by the difference between the temperature T _FR of the heater HT2 and the average temperature T _{FR _ a} at the time of CD measurement, ξ=T _FR −T _{FR _ a} .

Equation (24-1) is a model approximated by a linear function. The first and second terms 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 effect 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 first to third terms on the right side of the equation (24-2) are the equations on the right side of the above-mentioned equation (21-1), and are terms for predicting the CD of the measurement point from the temperature τ of the heater HT1 . The fourth to fifth terms on the right side of the 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) can be obtained separately (individually) as an equation for obtaining the CD of each measurement point of each divided region.

In the substrate processing apparatus 10 of this embodiment, in order to obtain data for generating a prediction model, each heater HT1 and heater HT2 are controlled so that the temperature of each divided region is at several levels, and the crystals are exchanged at each temperature. circle W, and the actual plasma etching is performed on each wafer W individually. For example, in the substrate processing apparatus 10, the temperature of each heater HT2 is fixed, the temperature of each heater HT1 is controlled to three or more, the wafers W are exchanged at each temperature, and the actual plasma etching is performed individually. . As an example, the substrate processing apparatus 10 performs plasma etching on the wafer W with each heater HT1 at 50°C. In addition, the substrate processing apparatus 10 performs plasma etching on the wafer W with each heater HT1 at 55°C. In addition, the substrate processing apparatus 10 performs plasma etching on the wafer W with each heater HT1 set to 45°C. In the substrate processing apparatus 10, the temperature of each heater HT1 is fixed, the temperature of each heater HT2 is controlled to two or more, the wafers W are exchanged at each temperature, and the actual plasma etching is performed individually. .

Each wafer W subjected to plasma etching at each temperature is transported to the measurement apparatus 11 , respectively. The measurement device 11 measures the CD of the measurement point with respect to each of the transferred wafers W using a predetermined position as the measurement point. The measurement device 11 transmits the data of the CD of each measurement point measured to the substrate processing device 10 .

This makes it possible to obtain data corresponding to τ, τ ² , ξ, ξ ² , and the value of CD of the measurement point, as represented by the following formula (25) at each measurement point.

[Equation 25]

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

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 HT1 and the heater HT2 based on the received data of the CD. For example, the generation unit 102a fits the equation (24-1) with the CD at each measurement point and the temperatures of the heaters HT1 and HT2 to obtain the values of the coefficients A ₁₀ , A ₁₁ , and F ₁₁ . The obtained coefficients A ₁₀ , A ₁₁ , and F ₁₁ are substituted into Equation (24-1), and the function of predicting the CD of the measuring point as a linear function of the temperature τ of the heater HT1 and the temperature ξ of the heater HT2 is obtained as the first 1 Predictive model. For example, the generation unit 102a obtains the equation (24-1) as the first prediction model.

In addition, the generation unit 102a generates a second prediction model in which the CD of the measurement point is modeled by the quadratic function of the heater HT1 and the heater HT2 based on the received data of the CD. For example, the generation unit 102a uses the CD of the measurement point and the temperature of each heater HT1 and heater HT2 to generate a value for each measurement point based on the CD data of the measurement point of each wafer W shown in the formula (25). The above equation (24-2) is fitted to obtain the values of the coefficients A ₂₀ , A ₂₁ , A ₂₂ , F ₂₁ , and F ₂₂ . For example, the generation unit 102a performs fitting, and obtains the values of the coefficients A ₂₀ , A ₂₁ , A ₂₂ , F ₂₁ , and F ₂₂ in which the residual sum of squares is the smallest.

For example, S _jk and S _kj are defined as the following formula (26-1), S _jCD is defined as the following formula (26-2), and x _i1 is defined as the following formula (26-3) Expressed in a manner, x _i2 is represented by the following equation (26-4), x _i3 is represented by the following equation (26-5), and x _i4 is represented by the following equation (26-6).

[Equation 26]

_j ，係x_j 的平均值。

_K ，係x_K 的平均值。

，係CD的平均值。here,

_j , the mean value of x _j .

_K is the mean value of x _K.

, the mean value of CD.

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

[Equation 27]

The equations (27-2) to (27-5) can be converted into equations (28) when a matrix is used.

[Equation 28]

The generating unit 102a obtains S _jk and S _jCD for j = 1 to 4 and k = 1 to 4, respectively, according to the equations (26-1) to (26-6) using the above-mentioned equation (25), and substitutes them into the equations (28), the values of the coefficients A ₂₁ , A ₂₂ , F ₂₁ , and F ₂₂ are obtained.

、τ² 的平均值

² 、ξ的平均值

、ξ² 的平均值

² 代入式(27-1)，求出係數A₂₀ 的值。The generation unit 102a calculates the average value of the obtained coefficients A ₂₁ , A ₂₂ , F ₂₁ , F ₂₂ , and τ

, the average value of τ ²

^2. Average value of ξ

, the average value of ξ ²

² is substituted into Equation (27-1), and the value of the coefficient A ₂₀ is obtained.

Then, the generation unit 102a substitutes the obtained coefficients A ₂₀ , A ₂₁ , A ₂₂ , F ₂₁ , and F ₂₂ into Expression (24-2) to generate a second prediction model.

The calculating part 102b calculates the target temperature of the heater HT1 and heater HT2 of each divided area|region whose CD of a measuring point satisfies predetermined conditions using the 1st prediction model and the 2nd prediction model generated by the generation part 102a.

For example, the calculation unit 102b uses the first prediction model to calculate the temperature τ of the heater HT1 in each divided area where the sum of squares of the errors of the CDs of the respective measurement points with respect to the target value μ is the smallest, as in the second embodiment. ^* _n , and the temperature ξ ^* _n of the heater HT2.

Then, the calculation unit 102b uses the calculated temperatures of the heater HT1 and the heater HT2 in each divided area as a reference, changes the temperature of the heater HT1 and the heater HT2 in each divided area, and calculates each of the divided areas using the second prediction model. The difference between the maximum value and the minimum value of the critical dimension of the measurement point is the target temperature of the heater HT1 and the heater HT2 in each divided region where the difference is the smallest. For example, the calculation unit 102b sets the heater HT1 and heater HT1 in each divided area as a reference, using the temperature τ ^* _n of the heater HT1 and the temperature ξ ^* _n of the heater HT2 in each divided area as a reference, respectively. With respect to the temperature change of HT2, the target temperature of heater HT1 and heater HT2 of each divided region in which the range of CD of each measurement point is the smallest is calculated by the above-mentioned formula (24-2). For example, the calculation unit 102b uses the temperature τ ^* _n of the heater HT1 in each divided area as a reference, and changes the temperature of the heater HT1 to positive and negative individually by a predetermined temperature, and then sets the temperature ξ of the heater HT2 by ξ ^* _n The CD of each measurement point is calculated as a predetermined temperature with positive and negative changes as a reference, and the combination of the temperatures of the heater HT1 and the heater HT2 in each divided region in which the range of the CD is the smallest is specified. Then, the calculation unit 102b sets a value obtained by adding a random number to the temperature of the heater HT1 in each divided area individually for the specified combination of the temperatures of the heater HT1 and the heater HT2 in each divided area. For example, Using the GRG method, the target temperature of the heater HT1 and the heater HT2 in each of the divided regions in which the CD range is the smallest is calculated. In addition, the calculation unit 102b may repeatedly set the temperature of the heater HT1 and the heater HT2 in each divided area to be lower than the predetermined temperature for the specified combination of the temperatures of the heater HT1 and the heater HT2 in each divided area. The CD of each measurement point is calculated randomly or according to a predetermined rule, and then the target temperature of heater HT1 and heater HT2 in each divided area where the CD range is the smallest is calculated.

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

As described above, the substrate processing apparatus 10 according to the third embodiment has the mounting surface on which the wafer W and the focus ring FR arranged so as to surround the wafer W are provided, and each division of the mounting surface is divided into Mounting tables (the first mounting table 116 and the second mounting table 120 ) of the heaters HT1 and HT2 whose temperature can be adjusted are respectively installed in the regions. The substrate processing apparatus 10 uses the temperature of the heaters HT1 and HT2 in each of the divided areas as parameters, and adds heaters of other divided areas corresponding to the distances between the measurement point and other divided areas other than the divided area including the measurement point. The influence of the temperature of HT1 and HT2, and a prediction model for predicting the critical dimension of the predetermined measurement point of the wafer W when a predetermined substrate process is performed on the wafer W placed on the mounting surface, and the critical dimension of the measurement point is calculated. The target temperature of the heaters HT1 and HT2 in each divided area that satisfies the predetermined conditions. The substrate processing apparatus 10 controls the heater HT1 and the heater HT2 of each divided area to the calculated target temperature when the substrate processing is performed on the wafer W placed on the placement surface. Thereby, the substrate processing apparatus 10 can control the temperature of the heater HT1 and the heater HT2 of each divided area so that the CD of the measurement point of the wafer W satisfies the predetermined condition.

(Fourth Embodiment) Next, a fourth embodiment will be described. The substrate processing system 1 and the substrate processing apparatus 10 of the fourth embodiment are the same as the substrate processing system 1 and the substrate processing of the first to third embodiments shown in FIGS. 1 to 3 , 10 , and 11 . The structure of the device 10 is the same, so the description is omitted. In the following, the fourth embodiment will be described using the structures of the substrate processing apparatuses 10 of the first embodiment and the second embodiment shown in FIGS. 1 to 3 , but it may also be shown in FIGS. The structure of the substrate processing apparatus 10 of the third embodiment is applied to the fourth embodiment.

FIG. 12 is a block diagram showing a schematic configuration of a control unit that controls the substrate processing apparatus according to the fourth embodiment. The control unit 100 that controls the substrate processing apparatus of the fourth embodiment has a part of the same structure as the control unit 100 of the first embodiment to the third embodiment shown in FIG. The same symbols are attached and descriptions thereof are omitted, and descriptions are mainly given for the different parts.

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

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

In the substrate processing apparatus 10 , the wafer W is subjected to plasma etching with the temperature of the heater HT of each divided region being the target temperature calculated by the calculation unit 102 b. Thereby, the range of the CD of each measurement point of the wafer W becomes the smallest.

In addition, the maximum point where the CD of the measurement point of the wafer W is the largest and the minimum point where the CD is the smallest may be located in the same division area.

FIG. 13 is a diagram schematically showing the maximum and minimum points of CD on the wafer. In FIG. 13(A) , the maximum point P1 at which the CD of the measurement point on the wafer W is the maximum and the minimum point P2 where the CD is the minimum are shown. In addition, in FIG. 13(A), the mounting area 18a of the mounting table 16 where the wafer W can be mounted is schematically shown. The placement area 18a is divided into a plurality of divided areas, and heaters HT are provided in each divided area. In the present embodiment, the placement area 18a is divided into a central circular area 150 and four annular areas 151 surrounding the circular area, which are five divided areas in total. That is, in the mounting table 16 , at least a part (annular region 151 ) of each divided region of the divided mounting region 18 a is provided along the circumferential direction of the wafer W. As shown in FIG. Heaters HT are provided in each of the divided regions (circular region 150 and annular region 151 ).

When the wafer W shown in FIG. 13(A) is placed in the placement area 18a, as shown in FIG. 13(B) , the maximum point P1 and the minimum point P2 are located in the same divided area. In the example of FIG. 13(B) , the maximum point P1 and the minimum point P2 are located within the same annular region 151 . The CD at the measurement point varies depending on the temperature of the heater HT. However, when the maximum point P1 and the minimum point P2 are located in the same divided area, since the temperature is controlled by the same heater HT, the CD of the maximum point P1 and the minimum point P2 will change in the same way according to the temperature of the heater HT. . Therefore, it becomes difficult to further narrow the range of CD.

At this time, as shown in FIG. 13(C) , when the wafer W is rotated and mounted on the mounting area 18a, the maximum point P1 and the minimum point P2 can be arranged in different divided areas. In the example of FIG. 13(C) , the maximum point P1 and the minimum point P2 may be arranged in different annular regions 151 . When the maximum point P1 and the minimum point P2 are arranged in different divided regions, the temperature can be controlled by the different heaters HT, so that the range of CD can be further reduced.

Then, the arrangement control unit 102e calculates the CD of each measurement point when the target temperature of each heater HT is set using the prediction model generated by the generation unit 102a. In addition, as the CD of the measurement point, the value measured by the measurement device 11 may also be used when plasma etching is actually performed.

The arrangement control unit 102e specifies the maximum point where the CD is the largest and the minimum point where the CD is the smallest among the CDs at each measurement point. The arrangement control unit 102e determines whether or not the maximum point and the minimum point are located in the same divided area. For example, the arrangement control unit 102e determines whether or not the maximum point and the minimum point are located in the same divided region provided along the circumferential direction of the wafer W. When the result of determination is that 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 relative to the mounting 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 controls the rotation of the wafer W in the circumferential direction so that the maximum point and the minimum point are located in different divided areas . For example, the control unit 102e is arranged to control the rotation of the wafer W in the circumferential direction so that the intermediate position between the maximum point and the minimum point is located on the boundary of the division area. For example, the arrangement control unit 102e is configured to control the rotation of the wafer W in the circumferential direction in a conveyance system for conveying the wafer W to the substrate processing apparatus 10 . In the transport system, an alignment device or a robot arm is provided before the substrate processing apparatus 10 . The alignment device is provided with a horizontal turntable, and can perform various alignment adjustments such as adjustment of the rotational position of the wafer W and the like. The robot arm holds the wafer W and transfers the wafer W to each device of the transfer system. For example, the configuration control unit 102e transmits control information for rotating the wafer W in the circumferential direction to the robot arm or the alignment device, and controls the rotation of the wafer W in the circumferential direction so that the intermediate position between the maximum point and the minimum point is located in the middle of the division area. boundaries.

The substrate processing apparatus 10 may generate the prediction model again when the arrangement of the wafers W with respect to the mounting surface is changed in this way. For example, the substrate processing apparatus 10 controls each heater HT so that the temperature of each divided region is at several levels, exchanges the wafer W at each temperature, and performs the actually performed plasma etching individually. Each wafer W subjected to the plasma etching process at each temperature is moved to the measurement device 11 , and the CD of the measurement point is measured by the measurement device 11 using a predetermined position of the wafer W as a measurement point. The measurement device 11 transmits the data of the CD of each measurement point measured to the substrate processing device 10 . The generation unit 102a generates a prediction model again based on the data of the received CD. The calculation unit 102b can use the prediction model generated by the generation unit 102a to calculate the target temperature of the heater HT in each divided area where the CD of the measurement point satisfies the predetermined condition.

In addition, when the change characteristic data representing the change of CD with respect to the temperature change is obtained, the substrate processing apparatus 10 may calculate the heater of each divided area using the prediction model before changing the arrangement of the wafer W with respect to the mounting surface. The target temperature for HT. For example, the calculating part 102b specifies the heater HT corresponding to each measurement point based on the rotation angle by which the wafer W is rotated. The calculation unit 102b corrects the prediction model so as to correct the value of CD according to the difference between the temperature of the heater HT before the change in the arrangement of the wafers W and the temperature of the heater HT after the change based on the change characteristic data for each measurement point . The calculation unit 102b can use the corrected prediction model to calculate the target temperature of the heater HT in each divided area where the CD of the measurement point satisfies the predetermined condition.

In this way, in the substrate processing apparatus 10 of the fourth embodiment, when the maximum point where the CD of the measurement point of the wafer W is the largest and the minimum point where the CD is the smallest are located in the same divided area, the wafer W is controlled relative to the placement of the wafer W. The configuration of the surface, so that the maximum point and the minimum point are located in different division areas. In this way, the substrate processing apparatus 10 can use different heaters HT to control the temperature of the maximum point where the CD is the largest and the minimum point where the CD is the smallest, so that the range of the CD can be further narrowed.

The present invention has been described above with reference to the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiments. In addition, it is clear from the description of the scope of claims that such modifications or improvements are also included in the technical scope of the present invention.

For example, the above-mentioned embodiment has been described by taking an example in which substrate processing is performed on a semiconductor wafer serving as a substrate, but the present invention is not limited to this. The substrate may be any substrate as long as the temperature affects the progress of the substrate processing.

In addition, the above-mentioned embodiment has been described by taking an example in which plasma etching is performed as a substrate treatment, but is not limited to this. The substrate treatment may be any substrate treatment as long as the temperature affects the progress of the treatment.

In addition, the above-mentioned third embodiment has been described by taking an example in which the mounting table is divided into the first mounting table 116 on which the wafer W is mounted and the second mounting table 120 on which the focus ring FR is mounted, but not only limited to this. The mounting table may be constituted by one stage, and the wafer W and the focus ring FR may be mounted on a mounting surface that is the same plane.

In addition, the above-mentioned third embodiment has been described by taking, as an example, the embodiment in which the focus ring FR is arranged as the annular member, but is not limited to this. The annular member may be, for example, an insulator formed of an insulating material such as quartz and provided to insulate or protect the placement surface. In addition, the annular member may be a focus ring FR and an insulator. At this time, for example, an insulator is arranged so as to surround the focus ring FR.

In addition, in the above-mentioned first to fourth embodiments, the calculation unit 102b calculates the target temperature of the heater in each divided area where the difference between the maximum value and the minimum value of the critical dimension of each measurement point is the smallest. This example is used as an example to illustrate, but it is not limited to this. The calculating part 102b may calculate the target temperature of the heater of each division|segmentation area|region in which the square sum of the deviation of the critical dimension of each measuring point becomes the smallest.

1‧‧‧Substrate processing system 10‧‧‧Substrate processing apparatus 100‧‧‧Control part 101‧‧‧Communication interface 102‧‧‧Program controller 102a‧‧‧Generating part 102b‧‧‧Calculating part 102c‧‧‧electrical Pulp control unit 102d‧‧‧Heater control unit 102e‧‧‧Configuration control unit 103‧‧‧User interface 104‧‧‧Memory unit 11‧‧‧Measurement device 116‧‧‧First stage 12‧‧‧Processing Container 120‧‧‧Second Mounting Table 120a‧‧‧ Mounting Surface 121‧‧‧Base 122‧‧‧Focus Ring Heater 123‧‧‧Insulator 12a‧‧‧Ground Conductor 12e‧‧‧Exhaust Port 12g ‧‧‧Importing and exporting exit 14‧‧‧Support part 150‧‧‧Circular area 151‧‧‧Annular area 16‧‧‧Place table 18‧‧‧Support member 18a‧‧‧Outside of placing area 18b‧‧‧ Surrounding area 18m‧‧‧Main body 19a, 19b, 19c, 19d‧‧‧Separation area 19l～19t‧‧‧Separation area 20‧‧‧Base 21‧‧‧Measurement point 22‧‧‧DC power supply 24‧‧‧ Refrigerant flow paths 26a, 26b‧‧‧Piping 30‧‧‧Upper electrode 32‧‧‧Insulating shielding member 34‧‧‧electrode plate 34a‧‧‧gas discharge hole 36‧‧‧electrode support body 36a‧‧‧gas diffusion Chamber 36b‧‧‧Gas flow hole 36c‧‧‧Gas inlet 38‧‧‧Gas supply pipe 40‧‧‧Gas source group 42‧‧‧Valve group 44‧‧‧Flow controller group 46‧‧‧Deposition block Plate 48‧‧‧Exhaust plate 50‧‧‧Exhaust device 52‧‧‧Exhaust pipe 54‧‧‧Gate valve E1‧‧‧Electrode FR‧‧‧Focus ring HFS‧‧‧First high frequency power supply HP‧‧ ‧Heater power supply HT, HT1, HT2‧‧‧Heater LFS‧‧‧Second high frequency power supply MU1, MU2‧‧‧Integrator N‧‧‧Network P1‧‧‧Maximum point P2‧‧‧Minimum point S ‧‧‧Processing spaces S10～S36, S13a, S15a, S16a, S18a‧‧‧Step SW1‧‧‧Switching W‧‧‧wafer

1 is a schematic configuration diagram of a substrate processing system according to an embodiment. 2 is a schematic diagram showing a substrate processing apparatus according to an embodiment. [ Fig. 3 ] is a plan view showing a mounting table according to an embodiment. 4 is a block diagram showing a schematic configuration of a control unit that controls a substrate processing apparatus according to an embodiment. [ Fig. 5 ] It is a diagram showing an example of a temperature distribution. [FIG. 6] It is a figure explaining the relationship of the division area|region. [ Fig. 7] Fig. 7 is a diagram illustrating an example of the relationship between the square sum of errors and the range. 8 is a flowchart showing an example of the flow of the temperature control method of the first embodiment. 9 is a flowchart showing an example of the flow of the temperature control method of the second embodiment. 10 is a diagram schematically showing a substrate processing apparatus according to a third embodiment. [ Fig. 11 ] It is a plan view showing a first stage and a second stage of 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. [ FIG. 13 ] It is a diagram schematically showing the maximum point and the minimum point of CD on the wafer.

Steps S10~S36‧‧‧

Claims (11)

A substrate processing apparatus, characterized by comprising: a mounting table provided with a mounting surface on which one or both of a substrate and a ring-shaped member arranged so as to surround the substrate are mounted, and divided A heater whose temperature can be adjusted is provided in each of the divided areas formed by the placement surface; the calculation unit uses "taking the temperature of the heater in each divided area as a parameter, adding the corresponding measurement point and the measurement point including the measurement point. The influence of the temperature of the heater in the other divided area is the influence of the distance of the divided area other than the divided area, and the predetermined measurement point of the substrate when the predetermined substrate processing is performed on the substrate placed on the mounting surface is predicted. A prediction model of the critical dimension of the measurement point", which calculates the target temperature of the heater in each segmented area where the critical dimension of the measurement point satisfies a predetermined condition; At the time of substrate processing, the heaters of the divided regions are controlled to the target temperature calculated by the calculation unit; a plurality of measurement points are set on the substrate; The temperature of the heater in each divided area where the sum of the squares of the errors of the critical dimensions of the measurement points becomes the smallest is calculated by changing the temperature of the heater in each divided area using the calculated temperature of each divided area as a reference. The difference between the maximum value and the minimum value of the critical dimensions of the measurement points, or the sum of the squares of the deviations of the critical dimensions of the measurement points, is the target temperature of the heater in each of the divided regions where the minimum value is obtained. According to the substrate processing apparatus of claim 1, wherein, The calculation unit calculates the temperature of the heater by adding "the influence of the temperature of the heater in the adjacent divided area corresponding to the distance between the measurement point and the divided area adjacent to the divided area including the measurement point" for prediction. The critical size of the measurement point satisfies the target temperature of the heater in each divided region where the predetermined condition is satisfied. The substrate processing apparatus according to claim 1 or 2, wherein the calculation unit calculates the temperature of each measurement point by changing the temperature of the heater in each divided area using the calculated temperature of each divided area as a reference. The average value of the critical dimension is within the range of the predetermined specification, and the difference between the maximum value and the minimum value of the critical dimension of each measurement point or the sum of the squares of the deviation of the critical dimension of each measurement point is the smallest. target temperature. The substrate processing apparatus according to claim 1 or 2, further comprising: a generating unit that controls the temperature of the heaters in each of the divided regions to three or more by measuring the temperature of the heaters in each of the divided regions, and executes the substrate processing on the substrate. The data of the critical dimension of the measuring point at the time of processing is used to generate the prediction model; the calculation unit uses the prediction model generated by the generation unit to calculate the heater of each divided area where the critical dimension of the measuring point satisfies a predetermined condition target temperature. The substrate processing apparatus according to claim 4, wherein the generating unit generates a first prediction model in which the critical dimension of the measurement point is modeled by a linear function of the temperature of the heater, and the critical dimension of the measurement point is generated dimensions to the temperature of the heater two times above the A second prediction model in which the sum of an exponential function and a constant of a function or the reciprocal of the absolute temperature of the heater is modeled; the calculation unit uses the first prediction model to calculate the sum of the squares of the errors of the critical dimension is the smallest among the divided regions; The temperature of the heater is based on the calculated temperature of each divided area, the temperature of the heater in each divided area is changed, and the second prediction model is used to calculate the maximum value and the minimum value of the critical dimension of each measurement point. The difference is the minimum target temperature of the heater of each divided area. The substrate processing apparatus according to claim 1 or 2 of the claimed scope, wherein, the substrate processing is plasma etching; the critical dimension is the width of the etched pattern. The substrate processing apparatus according to claim 1 or 2, wherein the annular member is one or both of a focus ring and an insulating ring. The substrate processing apparatus according to claim 1 or 2 of the claimed scope, further comprising: a configuration control unit, the maximum point where the critical dimension of the measuring point of the substrate is the largest is at the same position as the minimum point where the critical dimension is the smallest In the divided area, the arrangement of the substrate relative to the mounting surface is controlled so that the maximum point and the minimum point are located in different divided areas. The substrate processing apparatus according to claim 8, wherein the substrate is disc-shaped; In the mounting table, at least a part of each of the divided regions formed by dividing the mounting surface is provided along the circumferential direction of the substrate; the arrangement control unit is located along the maximum point and the minimum point. When the substrate is arranged in the same divided area in the circumferential direction, the substrate is controlled to rotate in the circumferential direction, so that the maximum point and the minimum point are located in different divided areas. A temperature control method, which is characterized by causing a computer to perform the following processing: (1) calculating a target temperature by using a prediction model for predicting a critical dimension; the critical dimension is provided with a mounting substrate and an annular ring arranged to surround the substrate the mounting surface of one or both of the components, and the substrate mounted on the mounting surface of the mounting table on which the temperature-adjustable heater is installed in each of the divided regions formed by dividing the mounting surface, The critical dimension of the predetermined measurement point of the substrate when the predetermined substrate processing is performed; the prediction model uses the temperature of the heater in each divided area as a parameter, and adds the corresponding measurement point and the measurement point. The influence of the temperature of the heater of the other divided area on the distance of the divided area other than the divided area; the calculated target temperature is the target temperature of the heater of each divided area where the critical dimension of the measurement point satisfies the predetermined condition and (2) when the substrate processing is performed on the substrate placed on the placement surface, the heaters of the respective divided regions are controlled to achieve the calculated target temperature; the measurement points are set in a plurality of substrates; use the The prediction model calculates the temperature of the heater in each divided area where the sum of the squares of the errors of the critical dimension of each measuring point with respect to the target size becomes the smallest. Using the calculated temperature of each divided area as a reference, let each divided area the temperature change of the heater, calculate the critical dimension of each measuring point The difference between the maximum value and the minimum value of , or the sum of the squares of the deviations of the critical dimensions of each measurement point is the target temperature of the heater in each segmented area with the smallest value. A temperature control program, which is characterized by causing a computer to execute the following processing: (1) calculating a target temperature using a prediction model for predicting a critical dimension; the critical dimension is provided with a mounting substrate and an annular ring arranged so as to surround the substrate. the mounting surface of one or both of the components, and the substrate mounted on the mounting surface of the mounting table on which the temperature-adjustable heater is installed in each of the divided regions formed by dividing the mounting surface, The critical dimension of the predetermined measurement point of the substrate when the predetermined substrate processing is performed; the prediction model uses the temperature of the heater in each divided area as a parameter, and adds the corresponding measurement point and the measurement point. The influence of the temperature of the heater of the other divided area on the distance of the divided area other than the divided area; the calculated target temperature is the target temperature of the heater of each divided area where the critical dimension of the measurement point satisfies the predetermined condition and (2) when the substrate processing is performed on the substrate placed on the placement surface, the heaters of the respective divided regions are controlled to achieve the calculated target temperature; the measurement points are set in a plurality of substrates; use the The prediction model calculates the temperature of the heater in each divided area where the sum of the squares of the errors of the critical dimension of each measuring point with respect to the target size becomes the smallest. Using the calculated temperature of each divided area as a reference, let each divided area According to the temperature change of the heater, the target temperature of the heater in each divided area is calculated as the difference between the maximum value and the minimum value of the critical dimension of each measurement point or the sum of the squares of the deviation of the critical dimension of each measurement point is the smallest.

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