JP7645828B2 - SUBSTRATE PROCESSING APPARATUS AND SUBSTRATE TEMPERATURE CORRECTING METHOD - Google Patents

Description

This disclosure relates to a substrate processing apparatus and a substrate temperature correction method.

Patent Document 1 proposes a technology for switching the temperature of a substrate by alternately supplying a temperature control medium of a first temperature and a temperature control medium of a second temperature to a flow path of a mounting table on which the substrate is placed. Patent Document 2 proposes a technology for adjusting the temperature of a substrate by adjusting the mixture ratio of a temperature control medium whose temperature has been adjusted to a first temperature by a low-temperature control unit and a temperature control medium whose temperature has been adjusted to a second temperature higher than the first temperature by a high-temperature control unit, and supplying the mixture to a flow path of the mounting table.

JP 2020-120045 A JP 2013-105359 A

The present disclosure provides a temperature control medium control method and a temperature control medium control device that can suppress temperature changes in a substrate caused by temperature changes in the temperature control medium.

A substrate processing apparatus according to one aspect of the present disclosure includes a mounting table, a gas supply unit, a measurement unit, and a control unit. The mounting table has a mounting surface on which a substrate is mounted, a flow path for flowing a temperature control medium formed therein, and an outlet port for discharging a heat transfer gas onto the mounting surface. The gas supply unit supplies the heat transfer gas to be discharged from the outlet port. The measurement unit measures the temperature of the temperature control medium flowing through the flow path. When the temperature of the temperature control medium measured by the measurement unit changes by more than a predetermined temperature, the control unit controls the pressure of the heat transfer gas supplied from the gas supply unit so as to cancel the temperature change of the substrate caused by the temperature change of the temperature control medium after a predetermined time has elapsed since the time of the change, during which a temperature change occurs in the substrate placed on the mounting surface due to the temperature change of the temperature control medium.

Various aspects and embodiments of the present disclosure can suppress temperature changes in the substrate caused by temperature changes in the temperature control medium.

FIG. 1 is a schematic cross-sectional view illustrating an example of a substrate processing apparatus according to an embodiment. FIG. 2 is a diagram illustrating an example of a schematic configuration of a temperature control device according to an embodiment. FIG. 3A is a diagram illustrating a switching operation of a temperature control medium by the temperature control device according to the embodiment. FIG. 3B is a diagram illustrating the temperature control medium switching operation performed by the temperature control device according to the embodiment. FIG. 4 is a graph showing an example of changes in temperature of the temperature control medium and the substrate according to the embodiment. FIG. 5 is a graph showing an example of changes in temperature of the temperature control medium and the substrate according to the embodiment. FIG. 6 is a diagram illustrating an example of how to obtain the predetermined time according to the embodiment. FIG. 7 is a diagram showing an example of the relationship between the pressure of the heat transfer gas and the temperature of the substrate according to the embodiment. FIG. 8 is a diagram showing an example of a change in the PT curve depending on the amount of heat input from the plasma to the substrate W according to the embodiment. FIG. 9 is a graph in which the vertical and horizontal axes of FIG. 7 are logarithmic. FIG. 10 is a diagram illustrating an example of correction of the temperature of the substrate according to the embodiment. FIG. 11 is a diagram illustrating control of the pressure of the heat transfer gas according to the embodiment. FIG. 12 is a flowchart showing an example of a substrate temperature correction method according to the embodiment. FIG. 13 is a diagram illustrating another example of correction of the temperature of the substrate according to the embodiment.

Below, embodiments of the disclosed substrate processing apparatus and substrate temperature correction method are described in detail with reference to the drawings. Note that the disclosed substrate processing apparatus and substrate temperature correction method are not limited to the following embodiments.

However, when attempting to change the temperature of the mounting table by changing the temperature of the temperature control medium flowing through the flow path of the mounting table, the temperature of the substrate may change due to the influence of the temperature change in the temperature control medium. For example, the temperature of the temperature control medium stored in the tank that stores the temperature control medium may change due to the influence of the returning temperature control medium when switching, and the temperature of the substrate may change due to the influence of the temperature change in the temperature control medium supplied from the tank. Also, when adjusting the temperature of the temperature control medium by adjusting the mixture ratio of the temperature control medium, the temperature of the temperature control medium may change if it is not possible to adjust the mixture ratio so that the temperature remains constant, and the temperature of the temperature control medium may change, causing the temperature of the substrate to change due to the influence of the temperature change in the temperature control medium.

When the temperature of a substrate changes, this can affect substrate processing. Therefore, this disclosure provides a technology that can suppress temperature changes in the substrate caused by temperature changes in the temperature control medium.

[Embodiment]
[Configuration of substrate processing apparatus 1]
An example of a substrate processing apparatus according to the present disclosure will be described. First, a substrate processing apparatus 1 according to an embodiment will be described. The substrate processing apparatus 1 performs substrate processing on a substrate W. In the embodiment, the substrate processing apparatus 1 is a plasma processing apparatus, and a plasma processing such as plasma etching is performed on a substrate W as the substrate processing. FIG. 1 is a schematic cross-sectional view showing an example of the substrate processing apparatus 1 according to the embodiment. In this embodiment, the substrate processing apparatus 1 is, for example, a plasma etching apparatus equipped with parallel plate electrodes. The substrate processing apparatus 1 includes an apparatus main body 10 and a control device 70. The apparatus main body 10 includes a processing vessel 12 made of a material such as aluminum, and having, for example, a substantially cylindrical shape. The processing vessel 12 has an inner wall surface anodized. The processing vessel 12 is also safety grounded.

A substantially cylindrical support 14 made of an insulating material such as quartz is provided on the bottom of the processing vessel 12. The support 14 extends vertically from the bottom of the processing vessel 12 (e.g., toward the upper electrode 30) within the processing vessel 12.

A mounting table 11 is provided in the processing vessel 12. The mounting table 11 is supported by a support portion 14. The mounting table 11 has a mounting surface 11a formed in the center of the upper surface on which a substrate W such as a semiconductor wafer is placed. The substrate W is placed on the mounting surface 11a of the mounting table 11. The mounting table 11 holds the substrate W placed on the mounting surface 11a. The mounting table 11 has an electrostatic chuck ESC and a lower electrode LE. The lower electrode LE is made of a metal material such as aluminum, and has a substantially disk-shaped shape. The electrostatic chuck ESC is disposed on the lower electrode LE. The upper surface of the electrostatic chuck ESC forms the mounting surface 11a.

The electrostatic chuck ESC has a structure in which an electrode EL, which is a conductive film, is disposed between a pair of insulating layers or between a pair of insulating sheets. A DC power supply 17 is electrically connected to the electrode EL via a switch SW. The electrostatic chuck ESC attracts the substrate W to the upper surface of the electrostatic chuck ESC by electrostatic forces such as Coulomb force generated by a DC voltage supplied from the DC power supply 17. This allows the electrostatic chuck ESC to hold the substrate W.

The mounting surface 11a of the mounting table 11 has an outlet 11b formed therein for discharging a heat transfer gas. A heat transfer gas, such as He gas, is supplied to the outlet 11b via a pipe 19. A gas supply unit 18 is connected to the pipe 19. The gas supply unit 18 supplies the heat transfer gas to the pipe 19. The heat transfer gas supplied via the pipe 19 is discharged from the outlet 11b and supplied between the electrostatic chuck ESC and the substrate W. By adjusting the pressure of the heat transfer gas supplied between the electrostatic chuck ESC and the substrate W, the thermal conductivity between the electrostatic chuck ESC and the substrate W can be adjusted.

An edge ring ER is arranged around the electrostatic chuck ESC so as to surround the edge of the substrate W and the electrostatic chuck ESC. The edge ring ER is sometimes called a focus ring. The edge ring ER can improve the in-plane uniformity of the processing on the substrate W. The edge ring ER is made of a material, such as quartz, that is appropriately selected depending on the material of the film to be etched.

Inside the lower electrode LE, a flow path 15 is formed through which a temperature control medium, which is an insulating fluid such as Galden (registered trademark), flows. A temperature control device 20 is connected to the flow path 15 via pipes 16a and 16b. The temperature control device 20 controls the temperature of the temperature control medium flowing through the flow path 15 of the lower electrode LE. The temperature control medium whose temperature has been controlled by the temperature control device 20 is supplied into the flow path 15 of the lower electrode LE via pipe 16a. The temperature control medium that has flowed through the flow path 15 is returned to the temperature control device 20 via pipe 16b.

The temperature control device 20 switches between a temperature control medium of a first temperature and a temperature control medium of a second temperature and supplies them into the flow path 15 of the lower electrode LE. By switching between the temperature control medium of the first temperature and the temperature control medium of the second temperature and supplying them into the flow path 15 of the lower electrode LE, the temperature of the electrode LE switches between the first temperature and the second temperature. The temperature of the mounting table 11 also switches between the first temperature and the second temperature. The first temperature is, for example, a temperature below 0°C. The second temperature is, for example, a temperature above room temperature.

A temperature sensor 21 is provided in the pipe 16a. The temperature sensor 21 measures the temperature of the temperature control medium flowing through the pipe 16a.

A power supply tube 69 for supplying high-frequency power to the lower electrode LE is electrically connected to the underside of the lower electrode LE. The power supply tube 69 is made of metal. Although not shown in FIG. 1, lifter pins and a lifter pin drive mechanism for transferring the substrate W on the electrostatic chuck ESC are arranged in the space between the lower electrode LE and the bottom of the processing vessel 12.

The first high frequency power supply 64 is connected to the power supply tube 69 via a matching device 68. The first high frequency power supply 64 is a power supply that generates high frequency power for attracting ions to the substrate W, i.e., high frequency bias power, and generates high frequency bias power with a frequency of, for example, 400 kHz to 40.68 MHz, for example, a frequency of 13.56 MHz. The matching device 68 is a circuit for matching the output impedance of the first high frequency power supply 64 with the input impedance on the load (lower electrode LE) side. The high frequency bias power generated by the first high frequency power supply 64 is supplied to the lower electrode LE via the matching device 68 and the power supply tube 69.

An upper electrode 30 is provided above the mounting table 11 at a position facing the mounting table 11. The lower electrode LE and the upper electrode 30 are arranged so as to be approximately parallel to each other. In the space between the upper electrode 30 and the lower electrode LE, plasma is generated, and the generated plasma is used to perform plasma processing such as etching on the substrate W held on the upper surface of the electrostatic chuck ESC. The space between the upper electrode 30 and the lower electrode LE is the processing space PS.

The upper electrode 30 is supported on the upper part of the processing vessel 12 via an insulating shielding member 32 made of, for example, quartz. The upper electrode 30 has an electrode plate 34 and an electrode support 36. The lower surface of the electrode plate 34 faces the processing space PS. A plurality of gas discharge ports 34a are formed in the electrode plate 34. The electrode plate 34 is made of, for example, a material containing silicon.

The electrode support 36 is made of a conductive material such as aluminum, and supports the electrode plate 34 from above in a removable manner. The electrode support 36 may have a water-cooled structure (not shown). A diffusion chamber 36a is formed inside the electrode support 36. A plurality of gas flow ports 36b extend downward (toward the mounting table 11) from the diffusion chamber 36a, which communicate with the gas discharge port 34a of the electrode plate 34. The electrode support 36 is provided with a gas inlet 36c for introducing a process gas into the diffusion chamber 36a, and a pipe 38 is connected to the gas inlet 36c.

A gas source group 40 is connected to the piping 38 via a valve group 42 and a flow controller group 44. The gas source group 40 has a plurality of gas sources. The valve group 42 includes a plurality of valves, and the flow controller group 44 includes a plurality of flow controllers such as mass flow controllers. Each of the gas source group 40 is connected to the piping 38 via a corresponding valve in the valve group 42 and a corresponding flow controller in the flow controller group 44.

As a result, the apparatus body 10 can supply the process gas from one or more gas sources selected from the gas source group 40 to the diffusion chamber 36a in the electrode support 36 at individually adjusted flow rates. The process gas supplied to the diffusion chamber 36a diffuses within the diffusion chamber 36a and is supplied in a shower-like manner into the processing space PS via the respective gas flow ports 36b and gas discharge ports 34a.

A second high frequency power supply 62 is connected to the electrode support 36 via a matching device 66. The second high frequency power supply 62 is a power supply that generates high frequency power for generating plasma, and generates high frequency power at a frequency of, for example, 27 to 100 MHz, for example, 60 MHz. The matching device 66 is a circuit for matching the output impedance of the second high frequency power supply 62 with the input impedance on the load (upper electrode 30) side. The high frequency power generated by the second high frequency power supply 62 is supplied to the upper electrode 30 via the matching device 66. The second high frequency power supply 62 may be connected to the lower electrode LE via the matching device 66.

A deposit shield 46 made of aluminum or the like having a surface coated with _Y2O3 , _quartz , or the like is detachably provided on the inner wall surface of the processing vessel 12 and the outer surface of the support 14. The deposit shield 46 prevents etching by-products (deposits) from adhering to the processing vessel 12 and the support 14.

An exhaust plate 48 is provided between the outer wall of the support 14 and the inner wall of the processing vessel 12 on the bottom side of the processing vessel 12 (the side where the support 14 is installed). The exhaust plate 48 is made of aluminum or the like whose surface is coated with _Y2O3 , _quartz or the like. An exhaust port 12e is provided below the exhaust plate 48. An exhaust device 50 is connected to the exhaust port 12e via an exhaust pipe 52.

The exhaust device 50 has a vacuum pump such as a turbo molecular pump. The exhaust device 50 can reduce the pressure in the space inside the processing vessel 12 to a desired vacuum level. An opening 12g is provided in the side wall of the processing vessel 12 for loading and unloading the substrate W. The opening 12g can be opened and closed by a gate valve 54.

The control device 70 is, for example, a computer. The operation of the device main body 10 configured as described above is generally controlled by the control device 70. The control device 70 has a control unit 71 and a storage unit 72. The control device 70 may also have a display unit that displays various information such as the processing status, and an operation unit such as a keyboard for performing various input operations.

The storage unit 72 is a storage device that stores various types of data. For example, the storage unit 72 is a storage device such as a hard disk, a solid state drive (SSD), or an optical disk. Note that the storage unit 72 may also be a semiconductor memory in which data can be rewritten, such as a random access memory (RAM), a flash memory, or a non-volatile static random access memory (NVSRAM).

The storage unit 72 stores the OS (Operating System) and various programs executed by the control unit 71. For example, the storage unit 72 stores various programs including a program that executes the processing of the substrate temperature correction method described below. Furthermore, the storage unit 72 stores various data used by the programs executed by the control unit 71. For example, the storage unit 72 stores parameter data 72a. Note that the storage unit 72 can also store other data in addition to the data exemplified above.

The parameter data 72a is data that stores the values of the parameters described below for each processing condition of the plasma processing. Details of the parameter data 72a will be described later.

The control unit 71 is a device such as a processor that controls each part of the apparatus main body 10. The control unit 71 can be an electronic circuit such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), or an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The control unit 71 has an internal memory for storing programs that define various processing procedures and control data, and executes various processes using these. The control unit 71 performs plasma processing by reading out a program stored in the storage unit 72 into the memory and executing it with a processor to control each part of the apparatus main body 10. The control unit 71 also performs processing of the substrate temperature correction method according to the embodiment.

[Configuration of temperature control device 20]
Next, a description will be given of a schematic configuration of the temperature control device 20. Fig. 2 is a diagram showing an example of a schematic configuration of the temperature control device 20 according to the embodiment.

The temperature control device 20 has a first switching unit 200, a second switching unit 201, a first temperature control unit 206, and a second temperature control unit 207.

The first temperature control unit 206 is connected to the pipe 16a via the pipe 220. The first temperature control unit 206 is also connected to the pipe 16b via the pipe 222. The first temperature control unit 206 controls the temperature of the temperature control medium to a first temperature. For example, the first temperature control unit 206 has a tank that stores the temperature control medium, and controls the temperature of the tank to control the temperature of the temperature control medium to the first temperature. The first temperature control unit 206 supplies the temperature control medium at the first temperature from the tank through the pipe 220 and the pipe 16a into the flow path 15 of the lower electrode LE. The temperature control medium supplied into the flow path 15 of the lower electrode LE is returned to the tank of the first temperature control unit 206 through the pipe 16b and the pipe 222.

The second temperature control unit 207 is connected to the pipe 16a and the pipe 220 at the connection position A via the pipe 227. The second temperature control unit 207 is also connected to the pipe 16b and the pipe 222 at the connection position B via the pipe 225. The second temperature control unit 207 controls the temperature of the temperature control medium to a second temperature higher than the first temperature. For example, the second temperature control unit 207 has a tank that stores the temperature control medium, and controls the temperature of the tank to the second temperature. The second temperature control unit 207 supplies the temperature control medium at the second temperature from the tank via the pipe 227 and the pipe 16a into the flow path 15 of the lower electrode LE. The temperature control medium supplied into the flow path 15 of the lower electrode LE is returned to the tank of the second temperature control unit 207 via the pipe 16b and the pipe 225.

The first temperature control unit 206 and the second temperature control unit 207 are connected by piping 208. The piping 208 adjusts the liquid level of the tank in the first temperature control unit 206 that stores the temperature control medium and the liquid level of the tank in the second temperature control unit 207 that stores the temperature control medium. This prevents leakage of the temperature control medium.

The first switching unit 200 is provided at the connection portion of the pipe 220 and the pipe 227 with the pipe 16a. The first switching unit 200 switches the temperature control medium flowing in the flow path 15 of the lower electrode LE. The first switching unit 200 has a first supply valve 2000 and a second supply valve 2001. The first supply valve 2000 is provided near the connection position A of the pipe 220 with the pipe 16a. The second supply valve 2001 is provided near the connection position A of the pipe 227 with the pipe 16a.

The second switching unit 201 is provided at the connection portion of the pipe 222 and the pipe 225 with the pipe 16b. The second switching unit 201 switches the output destination of the temperature control medium flowing out from the flow path 15 of the lower electrode LE to the first temperature control unit 206 or the second temperature control unit 207. The second switching unit 201 has a first return valve 2010 and a second return valve 2011. The first return valve 2010 is provided near the connection position B of the pipe 222 with the pipe 16b. The second return valve 2011 is provided near the connection position B of the pipe 225 with the pipe 16b.

In this embodiment, the first supply valve 2000, the second supply valve 2001, the first return valve 2010, and the second return valve 2011 are all two-way valves that can be switched between an open state and a closed state. The opening and closing of the first supply valve 2000, the second supply valve 2001, the first return valve 2010, and the second return valve 2011 are each controlled by the control unit 71.

Note that while FIG. 2 shows a schematic configuration of the temperature control device 20, the configuration of the temperature control device 20 is not limited to this. The temperature control device 20 may be configured to suppress water hammer, as described in Patent Document 1, for example.

[Temperature control medium switching operation]
3A and 3B are diagrams illustrating the switching operation of the temperature control medium by the temperature control device 20 according to the embodiment. In addition, in Fig. 3A and Fig. 3B, the open valves are drawn in white, and the closed valves are drawn in black.

The first temperature control unit 206 controls the temperature of the temperature control medium to a first temperature. The second temperature control unit 207 controls the temperature of the temperature control medium to a second temperature that is higher than the first temperature.

When circulating the temperature control medium at the first temperature through the flow path 15, the control unit 71 controls the first supply valve 2000 and the first return valve 2010 to an open state, and controls the second supply valve 2001 and the second return valve 2011 to a closed state. As a result, as shown in FIG. 3A, the temperature control medium at the first temperature is output from the first temperature control unit 206 and supplied into the flow path 15 of the lower electrode LE through the pipe 220, the first supply valve 2000, and the pipe 16a. The temperature control medium supplied into the flow path 15 of the lower electrode LE is returned to the first temperature control unit 206 through the pipe 16b, the first return valve 2010, and the pipe 222. As a result, the mounting table 11 is controlled to the first temperature.

On the other hand, when the temperature control medium at the second temperature is circulated through the flow path 15, the control unit 71 controls the first supply valve 2000 and the first return valve 2010 to a closed state, and controls the second supply valve 2001 and the second return valve 2011 to an open state. As a result, as shown in FIG. 3B, the temperature control medium at the second temperature is output from the second temperature control unit 207 and supplied into the flow path 15 of the lower electrode LE via the pipe 227, the second supply valve 2001, and the pipe 16a. In addition, the temperature control medium supplied into the flow path 15 of the lower electrode LE is returned to the second temperature control unit 207 via the pipe 16b, the second return valve 2011, and the pipe 225. As a result, the mounting table 11 is controlled to the second temperature.

However, when attempting to change the temperature of the substrate W by changing the temperature of the mounting table 11 by changing the temperature of the temperature control medium flowing through the flow path 15, the temperature of the substrate W may change due to the effect of the temperature change in the temperature control medium.

For example, when changing the temperature of the temperature control medium flowing through the flow path 15 of the mounting table 11 from a first temperature to a second temperature, the control unit 71 switches the opening and closing of the first supply valve 2000, the second supply valve 2001, the first return valve 2010, and the second return valve 2011 from the state shown in FIG. 3A to the state shown in FIG. 3B. In this case, when switching, the temperature control medium of the first temperature remaining in the flow path 15 flows into the tank of the second temperature control unit 207, and the temperature of the temperature control medium in the tank drops from the second temperature. The second temperature control unit 207 controls the temperature of the tank. Therefore, over time, the temperature of the temperature control medium in the tank returns to the second temperature. While the temperature of the temperature control medium in this tank drops from the second temperature, the temperature of the temperature control medium supplied from the second temperature control unit 207 to the flow path 15 of the mounting table 11 temporarily drops from the second temperature.

For example, when changing the temperature of the temperature control medium flowing through the flow path 15 of the mounting table 11 from the second temperature to the first temperature, the control unit 71 switches the opening and closing of the first supply valve 2000, the second supply valve 2001, the first return valve 2010, and the second return valve 2011 from the state shown in FIG. 3B to the state shown in FIG. 3A. In this case, when switching, the temperature control medium of the second temperature remaining in the flow path 15 flows into the tank of the first temperature control unit 206, and the temperature of the temperature control medium in the tank rises from the first temperature. The first temperature control unit 206 controls the temperature of the tank. Therefore, the temperature control medium supplied returns to the first temperature over time. While the temperature of the temperature control medium in this tank is rising from the first temperature, the temperature of the temperature control medium supplied from the first temperature control unit 206 to the flow path 15 of the mounting table 11 temporarily rises from the first temperature.

An example of the temperature change of the substrate W due to the influence of the temperature change of the temperature control medium flowing through the flow path 15 of the mounting table 11 will be described. FIG. 4 is a graph showing an example of the temperature change of the temperature control medium and the temperature change of the substrate W according to the embodiment. FIG. 4 shows a case where the substrate processing apparatus 1 performs a first plasma process on the substrate W by flowing a temperature control medium of a first temperature through the flow path 15 of the mounting table 11, and then performs a second plasma process by flowing a temperature control medium of a second temperature through the flow path 15 of the mounting table 11. FIG. 4 shows the waveforms of the change in temperature of the substrate W, the change in the actual temperature (actual temperature) of the temperature control medium supplied to the flow path 15 of the mounting table 11, and the change in the set temperature of the temperature control medium. The set temperature of the temperature control medium indicates the temperature of the ideal temperature control medium flowing through the flow path 15 of the mounting table 11. FIG. 4 also shows a period P1 in which the first plasma process is performed by supplying high-frequency power, and a period P2 in which the second plasma process is performed.

The temperature control device 20 circulates a temperature control medium at a first temperature through the flow path 15 of the mounting table 11 before the first plasma processing period P1. The temperature of the substrate W is at the first temperature T1 before the first plasma processing period P1, but rises from the first temperature T1 during period P1 due to heat input from the plasma.

When switching from the first plasma process to the second plasma process, the temperature control device 20 switches the temperature control medium supplied from the temperature control medium of the first temperature to the temperature control medium of the second temperature. In FIG. 4, the set temperature of the temperature control medium is switched from the first temperature T1 to the second temperature T2 between periods P1 and P2. The actual temperature of the temperature control medium supplied to the flow path 15 of the mounting table 11 rises sharply to the second temperature T2 due to the switching and temporarily stabilizes around temperature T2, but the temperature temporarily drops from the second temperature T2 due to the influence of the temperature control medium of the first temperature remaining in the flow path 15. The temperature of the substrate W rises and stabilizes due to the heat input from the plasma in period P2, but the temperature temporarily drops due to the influence of the temporary drop in the temperature of the temperature control medium.

Figure 5 is a graph showing an example of changes in temperature of the temperature control medium and the substrate temperature according to the embodiment. The upper part of Figure 5 shows an enlarged view of the portion of Figure 4 where a temporary temperature drop occurs in the temperature control medium and the substrate W. The lower part of Figure 5 shows changes in the pressure BP of the heat transfer gas. In Figure 5, the gas supply unit 18 supplies the heat transfer gas at a constant pressure BP. The temperature of the temperature control medium is transferred to the substrate W via the mounting table 11. Therefore, the temperature change of the temperature control medium is transferred to the substrate W with a delay. Therefore, the temporary temperature drop of the substrate W occurs with a delay compared to the temporary temperature drop of the temperature control medium. This change in temperature of the substrate W affects the second plasma processing process.

As shown in Figures 4 and 5, there is a time delay between when a temperature change occurs in the temperature control medium and when a temperature change occurs in the substrate W. For this reason, it is too early to correct the heat transfer gas pressure BP immediately after the temperature change occurs in the temperature control medium. Therefore, accuracy can be further improved by correcting the heat transfer gas pressure BP after a predetermined time Δwt has elapsed from the time the temperature control medium changes in temperature until a temperature change occurs in the substrate W due to the temperature change in the temperature control medium.

The predetermined time Δwt can be empirically determined. For example, the predetermined time Δwt can be determined by measuring the period from when the temperature of the temperature control medium actually changes to when the temperature of the substrate W changes, using the substrate processing apparatus 1 or an apparatus having the same characteristics as the substrate processing apparatus 1 (for example, an experimental plasma processing apparatus). FIG. 6 is a diagram for explaining an example of how to determine the predetermined time Δwt according to the embodiment. FIG. 6 shows the waveforms of the temperature change of the substrate W shown in FIG. 5, the actual temperature change of the temperature control medium supplied to the flow path 15 of the mounting table 11, and the set temperature change of the temperature control medium. FIG. 6 also shows the waveforms of the temperature change of the mounting table 11. The temperature changes of the substrate W and the mounting table 11 are almost synchronized. From the waveform of the change in the actual temperature of the temperature control medium, the elapsed time at which the actual temperature of the temperature control medium temporarily dropped the most is obtained. Also, from the waveform of the change in the temperature of the substrate W or the waveform of the change in the temperature of the mounting table 11, the elapsed time at which the temperature of the substrate W or the mounting table 11 temporarily dropped the most is obtained. The predetermined time Δwt is then calculated by determining the difference between the elapsed time when the actual temperature of the temperature control medium temporarily dropped the most and the elapsed time when the temperature of the substrate W or the mounting table 11 temporarily dropped the most. In the example of FIG. 6, the elapsed time when the actual temperature of the temperature control medium temporarily dropped the most is 106 [sec], and the elapsed time when the temperature of the substrate W or the mounting table 11 temporarily dropped the most is 126 [sec], so the predetermined time Δwt is calculated to be approximately 20 [sec].

In addition, the predetermined time Δwt can be determined theoretically. For example, the predetermined time Δwt can be calculated from the following formula (1):

Δwt = t1+t2-t3 (1)

Where:
t1 is a delay time that depends on the piping volume.
t2 is the time it takes for heat to be transferred from the temperature control medium to the substrate W.
t3 is the time it takes from when the gas supply unit 18 receives an instruction to change the pressure of the heat transfer gas until the pressure BP is actually changed.

t1 is the time it takes for the temperature control medium remaining in the flow path 15 etc. to flow out. t1 is determined by the installation positions of the flow path 15, pipes 16a and 16b, and temperature sensor 21. For example, let L be the length from the installation position of the temperature sensor 21 in pipe 16a to the end of pipe 16b that has passed through flow path 15. Let the inner cross-sectional area of flow path 15 and pipes 16a and 16b be the same, and let S be the inner cross-sectional area. Let V be the flow velocity of the temperature control medium. In this case, it is calculated using the following formula (2).

t1 = L×S÷V (2)

For example, when the length L is 4.5 [m], the cross-sectional area S is 2.85E ^-4 [m ² ], and the flow velocity V of the temperature control medium is 0.5 [L/sec], t1 is obtained from equation (2) as follows:

t1=4.5×2.85E ^-4 ÷0.5=2.6[sec]

t2 is the time it takes for the heat in the flow path 15 of the mounting table 11 to be transferred to the substrate W, i.e., the time constant (τ), and can be calculated from the thermal resistance and heat capacity between the flow path 15 of the mounting table 11 and the substrate W. For example, it can be calculated from the thermal resistance and heat capacity of each layer between the flow path 15 of the mounting table 11 and the substrate W, such as the electrostatic chuck ESC and the lower electrode LE portion, using formula (3).

t2 = τ = Σ (thermal resistance x heat capacity) (3)

t3 is obtained by measuring the time it takes from when the gas supply unit 18 receives an instruction to change the pressure of the heat transfer gas to when the pressure BP is actually changed, using an actual substrate processing apparatus 1 or an apparatus with similar characteristics to the substrate processing apparatus 1 (e.g., an experimental plasma processing apparatus).

When the pressure of the heat transfer gas discharged from the discharge port 11b of the mounting table 11 increases, the thermal conductivity between the electrostatic chuck ESC and the substrate W increases, and the temperature of the substrate W decreases. When the pressure of the heat transfer gas discharged from the discharge port 11b of the mounting table 11 decreases, the thermal conductivity between the electrostatic chuck ESC and the substrate W decreases, and the temperature of the substrate W increases. FIG. 7 is a diagram showing an example of the relationship between the pressure BP of the heat transfer gas and the temperature Tw of the substrate W according to the embodiment. FIG. 7 shows a PT curve showing the relationship between the pressure BP of the heat transfer gas and the temperature Tw of the substrate W. The temperature Tw of the substrate W decreases as the pressure BP of the heat transfer gas supplied from the gas supply unit 18 increases.

The relationship between the pressure BP of the heat transfer gas and the temperature Tw of the substrate W changes depending on the amount of heat input from the plasma to the substrate W. FIG. 8 is a diagram showing an example of the change in the PT curve depending on the amount of heat input Q from the plasma to the substrate W in an embodiment. When the amount of heat input Q from the plasma to the substrate W is large, the PT curve moves generally upward.

Figure 9 is a diagram in which the vertical and horizontal axes of Figure 7 are logarithmic. The PT curve showing the relationship between the heat transfer gas pressure BP and the substrate W temperature Tw as in Figure 9 becomes a linear relationship when the substrate W temperature Tw and the heat transfer gas pressure BP are each logarithmic. Therefore, the PT curve can be approximated by a logarithmic function. For example, the PT curve can be expressed as shown in the following equation (4-1), and from equation (4-1), it can be expressed as equation (4-2).

ln(T)=a×ln(P)+b (4-1)
T=P ^a ×e ^b (4-2)
Where:
a and b are parameters.
T is the temperature of the substrate W.
P is the pressure of the heat transfer gas supplied.

Next, the correction of the temperature of the substrate W will be described. FIG. 10 is a diagram illustrating an example of the correction of the temperature of the substrate W according to the embodiment. FIG. 10 shows a PT curve, and an enlarged view of a portion of the curve is shown at the bottom. When the supply temperature of the temperature control medium changes by ΔT [°C], the temperature Tw of the substrate W also changes from T to T+ΔT. The correction amount of the heat transfer gas pressure BP to return the temperature Tw of the substrate W from T+ΔT to T is ΔP.

When (P, T + ΔT) and (P + ΔP, T) are substituted into equation (4-2), we obtain the following equations (5-1) and (5-2).

T+ΔT=P ^a ×e ^b (5-1)
T = (P+ΔP) ^a ×e ^b (5-2)

Eliminating T using equations (5-1) and (5-2) gives the following equation (6).

(P+ΔP) ^a ×e ^b +ΔT=P ^a ×e ^b (6)

Rearranging equation (6) into an equation for ΔP gives the following equation (7).

ΔP=(P ^a -ΔT/e ^b ) ^1/a - P (7)

Therefore, once the parameters a and b are determined, the correction amount ΔP of the heat transfer gas pressure BP to change the temperature Tw of the substrate W by ΔT can be obtained from equation (7).

As shown in FIG. 8, the PT curve showing the relationship between the pressure BP of the heat transfer gas and the temperature Tw of the substrate W varies depending on the amount of heat input Q from the plasma to the substrate W. The amount of heat input Q from the plasma to the substrate W varies depending on the processing conditions of the plasma processing. Therefore, by determining a PT curve for each processing condition of the plasma processing in advance and obtaining equation (4-2) that approximates each PT curve, it is possible to determine parameters a and b in advance for each processing condition of the plasma processing.

Parameter data 72a stores parameters a and b for each processing condition of the plasma processing.

The control unit 71 controls the pressure BP of the heat transfer gas from the gas supply unit 18 so as to counteract the temperature change of the substrate W due to the temperature change of the temperature control medium. For example, the control unit 71 determines whether the temperature of the temperature control medium measured by the temperature sensor 21 has changed by more than a predetermined temperature. The predetermined temperature is determined according to the range of allowable temperature change of the temperature control medium. The predetermined temperature is, for example, 5°C. When the temperature of the temperature control medium has changed by more than the predetermined temperature, the control unit 71 controls the pressure BP of the heat transfer gas from the gas supply unit 18 so as to counteract the temperature change of the substrate W due to the temperature change of the temperature control medium after a predetermined time Δwt has elapsed from the time of the change.

For example, when the temperature of the temperature control medium measured by the temperature sensor 21 changes from the first temperature by a predetermined temperature or more while a temperature control medium of a first temperature is being supplied from the temperature control device 20 to the flow path 15, and when the temperature of the temperature control medium measured by the temperature sensor 21 changes from the second temperature by a predetermined temperature or more while a temperature control medium of a second temperature is being supplied from the temperature control device 20 to the flow path 15, the control unit 71 controls the pressure BP of the heat transfer gas from the gas supply unit 18 after a predetermined time Δwt from the timing of the change. When the temperature of the temperature control medium changes to a temperature higher than the predetermined temperature, the control unit 71 controls to increase the pressure BP of the heat transfer gas from the gas supply unit 18, and when the temperature of the temperature control medium changes to a temperature lower than the predetermined temperature, the control unit 71 controls to decrease the pressure BP of the heat transfer gas from the gas supply unit 18.

For example, the control unit 71 uses a relational equation showing the relationship between the pressure BP of the heat transfer gas supplied from the gas supply unit 18 and the temperature Tw of the substrate W to determine a correction amount ΔP of the heat transfer gas pressure BP to correct the temperature change of the substrate W. Specifically, the control unit 71 identifies the values of parameters a and b corresponding to the heat input of the plasma processing being performed or the processing conditions of the plasma processing when the temperature changes from the parameter data 72a. The control unit 71 uses equation (7) to which the identified values of parameters a and b are applied to determine a correction amount ΔP of the heat transfer gas pressure BP to correct the temperature change of the substrate W. Then, the control unit 71 performs control to change the pressure BP of the heat transfer gas supplied from the gas supply unit 18 by the correction amount ΔP after a predetermined time Δwt from the timing of the change.

Figure 11 is a diagram for explaining the control of the heat transfer gas pressure BP according to the embodiment. The upper part of Figure 11 shows the waveforms of the change in the actual temperature of the temperature control medium supplied to the flow path 15 of the mounting table 11 and the change in the set temperature of the temperature control medium, which are the same as those in Figure 5. The lower part of Figure 11 shows the change in the heat transfer gas pressure BP. The upper part of Figure 11 shows the waveform of the change in the temperature Tw of the substrate W after correction by controlling the heat transfer gas pressure BP.

When the temperature of the temperature control medium measured by the temperature sensor 21 has reached a steady state and the temperature of the temperature control medium has changed by more than a predetermined temperature, the control unit 71 controls the pressure BP of the heat transfer gas from the gas supply unit 18 so as to cancel the temperature change of the substrate W due to the temperature change of the temperature control medium. For example, the control unit 71 determines that the temperature of the temperature control medium has reached a steady state when the temperature of the temperature control medium measured by the temperature sensor 21 is within a certain range (e.g., 3°C) regarded as a steady state from the set temperature of the temperature control medium. The control unit 71 may also determine that the temperature of the temperature control medium has reached a steady state when the change in the temperature of the temperature control medium is within the certain range even for a certain period of time. When the temperature of the temperature control medium has reached a steady state, the control unit 71 determines whether the temperature of the temperature control medium measured by the temperature sensor 21 has changed by more than a predetermined temperature.

In FIG. 11, at timing ta, the temperature of the temperature control medium measured by the temperature sensor 21 changes by more than a predetermined temperature. The control unit 71 controls the pressure BP of the heat transfer gas from the gas supply unit 18 so as to cancel the temperature change of the substrate W due to the temperature change of the temperature control medium after a predetermined time Δwt has elapsed since timing ta. In FIG. 11, a temperature control medium of a second temperature is supplied to the flow path 15. The control unit 71 controls the pressure BP of the heat transfer gas from the gas supply unit 18 to be reduced at timing tb, which is a predetermined time Δwt after timing ta. For example, the control unit 71 identifies the values of parameters a and b corresponding to the processing conditions of the second plasma processing being performed when the temperature of the temperature control medium changes by more than a predetermined temperature from the parameter data 72a. The control unit 71 calculates the correction amount ΔP of the pressure BP of the heat transfer gas using equation (7) to which the identified values of parameters a and b are applied. At timing tb, the control unit 71 controls the pressure BP of the heat transfer gas supplied from the gas supply unit 18 to be reduced by a correction amount ΔP.

When the pressure of the heat transfer gas discharged from the discharge port 11b of the mounting table 11 decreases, the thermal conductivity between the electrostatic chuck ESC and the substrate W decreases, and the temperature of the substrate W increases. Therefore, the pressure BP of the heat transfer gas supplied from the gas supply unit 18 decreases, and the temperature of the substrate W increases. As a result, the temperature of the substrate W is corrected as shown by the wavy line in FIG. 11. In this way, the substrate processing apparatus 1 can suppress temperature changes of the substrate W caused by the temperature change of the temperature control medium even if the temperature of the temperature control medium flowing through the flow path 15 of the mounting table 11 changes.

[Substrate temperature correction method]
Fig. 12 is a flowchart showing an example of a substrate temperature correction method according to an embodiment. The substrate temperature correction method shown in Fig. 12 is realized by the control unit 71 controlling each part of the apparatus main body 10. The control unit 71 starts the process shown in Fig. 12 when the temperature of the temperature adjustment medium reaches a steady state.

The control unit 71 measures the temperature of the temperature control medium using the temperature sensor 21 (S10). The control unit 71 determines whether the temperature of the temperature control medium measured by the temperature sensor 21 has changed by a predetermined temperature or more (S11). If the temperature of the temperature control medium has not changed by the predetermined temperature or more (S11: No), the process returns to S10 described above.

On the other hand, if the temperature of the temperature control medium has changed by more than the predetermined temperature (S11: Yes), the control unit 71 identifies the values of parameters a and b corresponding to the processing conditions of the second plasma processing being performed from the parameter data 72a (S12). The control unit 71 uses equation (7) to which the identified values of parameters a and b are applied to determine the correction amount ΔP of the pressure BP of the heat transfer gas to correct the temperature change of the substrate W (S13).

The control unit 71 determines whether a predetermined time Δwt has elapsed since the timing ta at which the temperature of the temperature control medium changed by a predetermined temperature or more (S14). If the predetermined time Δwt has not elapsed (S14: No), the process returns to S14 described above.

On the other hand, if the predetermined time Δwt has elapsed (S14: Yes), the control unit 71 performs control to change the pressure BP of the heat transfer gas supplied from the gas supply unit 18 by a correction amount ΔP (S15), and ends the process. Note that when the process ends, the control unit 71 may perform the process of the substrate temperature correction method shown in FIG. 12 again.

As described above, the substrate processing apparatus 1 according to the embodiment includes the mounting table 11, the gas supply unit 18, the measurement unit (temperature sensor 21), and the control unit 71. The mounting table 11 has a mounting surface 11a on which the substrate W is mounted, a flow path 15 for flowing the temperature control medium formed therein, and an outlet 11b for discharging the heat transfer gas to the mounting surface 11a. The gas supply unit 18 supplies the heat transfer gas to be discharged from the outlet 11b. The measurement unit measures the temperature of the temperature control medium to be flowed through the flow path 15. When the temperature of the temperature control medium measured by the measurement unit changes by a predetermined temperature or more, the control unit 71 controls the pressure BP of the heat transfer gas supplied from the gas supply unit 18 so as to cancel the temperature change of the substrate W due to the temperature change of the temperature control medium after a predetermined time Δwt has elapsed since the time of the change, at which a temperature change occurs in the substrate W placed on the mounting surface 11a due to the temperature change of the temperature control medium. This allows the substrate processing apparatus 1 to suppress temperature changes in the substrate W caused by temperature changes in the temperature control medium.

Furthermore, the control unit 71 controls the pressure BP of the heat transfer gas supplied from the gas supply unit 18 to be increased when the temperature of the temperature control medium changes to be higher than a predetermined temperature, and controls the pressure BP of the heat transfer gas supplied from the gas supply unit 18 to be decreased when the temperature of the temperature control medium changes to be lower than a predetermined temperature. In this way, by increasing the heat transfer gas pressure BP, the thermal conductivity between the mounting table 11 and the substrate W increases, and by decreasing the heat transfer gas pressure BP, the thermal conductivity between the mounting table 11 and the substrate W decreases, so that the temperature change of the substrate W due to the temperature change of the temperature control medium can be suppressed.

The control unit 71 also uses a relational equation (e.g., equation (7)) showing the relationship between the pressure BP of the heat transfer gas supplied from the gas supply unit 18 and the temperature of the substrate W to determine a correction amount ΔP of the heat transfer gas pressure BP for correcting the temperature change of the substrate W, and performs control to change the pressure BP of the heat transfer gas supplied from the gas supply unit 18 by the correction amount ΔP after a predetermined time Δwt has elapsed from the timing of the change. This allows the substrate processing apparatus 1 to correct the pressure BP of the heat transfer gas by the amount required to correct the temperature change of the substrate W, thereby reducing the temperature change of the substrate W caused by the temperature change of the temperature control medium.

The relational expression also includes parameters a and b. The memory unit 72 stores parameter data 72a that stores the values of the parameters a and b of the relational expression for each heat input of the plasma processing or processing condition of the plasma processing. The control unit 71 identifies the values of the parameters a and b from the parameter data 72a that correspond to the heat input of the plasma processing or the processing condition of the plasma processing being performed when the temperature of the temperature control medium measured by the measurement unit changes by a predetermined temperature or more. Then, the control unit 71 uses the relational expression to which the identified values of the parameters a and b are applied to determine a correction amount ΔP of the pressure BP of the heat transfer gas for correcting the temperature change of the substrate W. This allows the substrate processing apparatus 1 to determine the correction amount ΔP according to the plasma processing being performed, thereby making it possible to further reduce the temperature change of the substrate W due to the influence of the temperature change of the temperature control medium.

The temperature control medium supply unit (temperature control device 20) circulates the temperature control medium with the flow path 15, and switches between a temperature control medium of a first temperature or a temperature control medium of a second temperature higher than the first temperature and supplies it to the flow path 15. When the temperature control medium measured by the measuring unit changes from the first temperature by a predetermined temperature or more while the temperature control medium of the first temperature is being supplied from the temperature control medium supply unit to the flow path 15, and when the temperature control medium measured by the measuring unit changes from the second temperature by a predetermined temperature or more while the temperature control medium of the second temperature is being supplied from the temperature control medium supply unit to the flow path 15, the control unit 71 controls the pressure BP of the heat transfer gas supplied from the gas supply unit 18 after a predetermined time Δwt has elapsed from the timing of the change. This allows the substrate processing apparatus 1 to suppress temperature changes in the substrate W due to the influence of temperature changes in the temperature control medium.

The predetermined time Δwt is determined by measuring the period from when the temperature of the temperature control medium changes until a temperature change occurs in the substrate W. This allows the pressure BP of the heat transfer gas to be corrected at the timing when a temperature change actually occurs in the substrate W after the temperature of the temperature control medium changes, thereby making it possible to reduce the temperature change in the substrate W caused by the temperature change in the temperature control medium.

The predetermined time Δwt is calculated from delay time t1, which depends on the piping volume, time t2, which is the time it takes for heat to be transferred from the temperature control medium to the substrate, and time t3, which is the time it takes from issuing a command to change the pressure of the heat transfer gas until the pressure BP is actually changed. This makes it possible to logically determine the predetermined time Δwt without measuring it.

Although the embodiments have been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the claims.

For example, in the above embodiment, the substrate W is a semiconductor wafer. However, the disclosed technology is not limited thereto. The substrate W may be any type.

In the above embodiment, the temperature control device 20 controls the temperature of the substrate W by switching between supplying a temperature control medium of a first temperature T1 and a temperature control medium of a second temperature T2 to the flow path 15 of the mounting table 11. However, the disclosed technology is not limited to this. The temperature control device 20 may be configured to adjust the temperature of the substrate W by, for example, applying a configuration such as that of Patent Document 2, mixing a temperature control medium of a first temperature T1 and a temperature control medium of a second temperature T2 to a set temperature and supplying the resulting mixture to the flow path 15 of the mounting table 11. Even in this case, the temperature change of the substrate W due to the effect of the temperature change of the temperature control medium can be suppressed.

In the above-described embodiment, a case where a temperature change occurs in the temperature control medium due to the influence of the temperature control medium remaining in the flow path 15 when switching between the first temperature T1 and the second temperature T2 of the temperature control medium has been described as an example. However, the disclosed technology is not limited thereto. The substrate temperature correction method of the present disclosure can be applied to suppress a temperature change in the substrate W due to the influence of the temperature change in the temperature control medium, regardless of the cause of the temperature change in the temperature control medium. FIG. 13 is a diagram for explaining another example of the correction of the temperature of the substrate W according to the embodiment. FIG. 13 shows a case where a temperature change ΔT _B occurs in the temperature control medium when a temperature control medium of a constant temperature is supplied to the flow path 15 of the mounting table 11, and a temperature change ΔT _W occurs in the substrate W due to the influence of the temperature change ΔT _B of the temperature control medium. Even in such a case, the pressure BP of the heat transfer gas is controlled so as to cancel the temperature change ΔT _W of the substrate W after a predetermined time Δwt has elapsed from the timing when the temperature change ΔT _B occurs, thereby suppressing the temperature change ΔT _W of the substrate due to the influence of the temperature change ΔT _B of the temperature control medium.

In the above embodiment, the parameter data 72a storing the values of the parameters a and b of the relational equation for each heat input of the plasma processing or processing condition of the plasma processing is described as an example. However, the disclosed technology is not limited to this. For each heat input of the plasma processing or processing condition of the plasma processing, a relational equation (for example, equation (7)) to which the values of the parameters a and b corresponding to the processing condition are applied may be stored in the storage unit 72. The control unit 71 may identify a relational equation corresponding to the heat input of the plasma processing being performed or the processing condition of the plasma processing from the storage unit 72, and use the identified relational equation to determine the correction amount ΔP of the pressure BP of the heat transfer gas for correcting the temperature change of the substrate W. In addition, when there is only one relational equation corresponding to the plasma processing, the control unit 71 may incorporate the relational equation into the program, and use the incorporated relational equation to determine the correction amount ΔP of the pressure BP of the heat transfer gas for correcting the temperature change of the substrate W.

In the above embodiment, the correction amount ΔP required to return the temperature Tw of the substrate W to the original state when the temperature of the temperature control medium changes by a predetermined temperature or more is calculated. However, the disclosed technology is not limited to this. Even if the temperature change of the temperature control medium is rapid, if the period of the temperature change is short, the change in the temperature Tw of the substrate W is small. On the other hand, even if the temperature change of the temperature control medium is gradual, if the period of the temperature change is long, the change in the temperature Tw of the substrate W is large. In this way, the change in the temperature Tw of the substrate W differs depending on the shape of the waveform of the temperature change of the temperature control medium. Therefore, the control unit 71 may control the pressure BP of the heat transfer gas supplied from the gas supply unit 18 depending on the shape of the waveform of the temperature change when the temperature of the temperature control medium changes by a predetermined temperature or more. For example, the control unit 71 may calculate the correction amount of the pressure BP of the heat transfer gas from the shape of the waveform of the temperature change of the temperature control medium. For example, for each type of shape of the waveform of the temperature change of the temperature control medium, a correction coefficient for correcting the correction amount ΔP is calculated by experiment or the like so that the temperature change of the substrate W is small, and is stored in the storage unit 72 as correction coefficient data. When a temperature change ΔT _B occurs in the temperature control medium, the control unit 71 identifies the type of waveform shape of the temperature change ΔT _B and identifies a correction coefficient corresponding to the identified type from the correction coefficient data. The control unit 71 may multiply the identified correction coefficient by the correction amount ΔP to correct the correction amount, and perform control to change the pressure BP of the heat transfer gas supplied from the gas supply unit 18 by the corrected correction amount. This makes it possible to determine the correction amount corresponding to the waveform of the temperature change of the temperature control medium, thereby suppressing the temperature change of the substrate.

In the above-described embodiment, the thermal conductivity between the mounting table 11 and the substrate W is adjusted by adjusting the pressure of the heat transfer gas supplied between the mounting table 11 and the substrate W. However, the disclosed technology is not limited to this. A temperature control medium flows through the flow path 15 formed inside the substrate table 11, and the thermal conductivity between the temperature control medium and the mounting table 11 can be adjusted by the flow rate of the temperature control medium. For example, by increasing the flow rate of the temperature control medium, the thermal conductivity between the temperature control medium and the mounting table 11 increases. On the other hand, by decreasing the flow rate of the temperature control medium, the thermal conductivity between the temperature control medium and the mounting table 11 decreases. Therefore, when the temperature of the temperature control medium measured by the measuring unit changes by a predetermined temperature or more, the control unit 71 may adjust the thermal conductivity between the temperature control medium and the substrate W placed on the mounting surface 11a after a predetermined time Δwt has elapsed from the timing of the change so as to cancel the temperature change of the substrate W due to the temperature change of the temperature control medium. The control unit 71 controls the temperature control medium to increase the thermal conductivity between the temperature control medium and the substrate W placed on the placement surface 11a when the temperature of the temperature control medium changes to be higher than a predetermined temperature, and controls the thermal conductivity between the temperature control medium and the substrate W placed on the placement surface 11a to be lowered when the temperature of the temperature control medium changes to be lower than a predetermined temperature. For example, the control unit 71 controls the flow rate of the temperature control medium flowing through the flow path 15 to be faster when the temperature of the temperature control medium changes to be higher than a predetermined temperature, and controls the flow rate of the temperature control medium flowing through the flow path 15 to be slower when the temperature of the temperature control medium changes to be lower than a predetermined temperature. As an example of controlling the flow rate of the temperature control medium, when a valve is installed between the pipe 16a and the flow path 15, or at least one of the flow path 15 and the pipe 16b, the flow rate can be controlled by adjusting the opening of the installed valve. Alternatively, the flow rate of the temperature control medium may be controlled by providing a function that can change the cross-sectional area of the flow path 15. Alternatively, the flow rate of the temperature control medium discharged from the temperature control device 20 to the pipe 16 may be adjusted. These can adjust the thermal conductivity between the temperature control medium and the substrate W placed on the mounting surface 11a. The thermal conductivity between the temperature control medium and the mounting table 11 is part of the thermal conductivity between the temperature control medium and the substrate W placed on the mounting surface 11a. In addition, by combining this with adjusting the pressure of the heat transfer gas supplied between the mounting table 11 and the substrate W, the thermal conductivity between the temperature control medium and the substrate W placed on the mounting surface 11a can be adjusted.

In the above-described embodiment, a capacitively coupled plasma (CCP) is used as an example of a plasma source. However, the disclosed technology is not limited to this. As a plasma source, for example, an inductively coupled plasma (ICP), a microwave excited surface wave plasma (SWP), an electron cyclotron resonance plasma (ECP), or a helicon wave excited plasma (HWP) may be used.

In the above embodiment, a case has been described in which plasma processing such as plasma etching is performed on the substrate W as substrate processing, but this is not limited to this. The substrate processing may be any processing that generates heat input to the substrate W. For example, the substrate processing may be a heat treatment such as ashing.

In the above embodiment, the substrate processing apparatus 1 is described as a plasma processing apparatus that performs plasma processing. However, the disclosed technology is not limited to this. The substrate processing apparatus 1 may be any apparatus that performs substrate processing that generates heat input to the substrate W. For example, the substrate processing apparatus 1 may be a film forming apparatus, a modification apparatus, etc.

The disclosed embodiments should be considered in all respects as illustrative and not restrictive. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

LE Lower electrode W Substrate 1 Substrate processing apparatus 10 Apparatus body 11 Mounting table 11a Mounting surface 11b Discharge port 12 Processing vessel 15 Flow path 16a Pipe 16b Pipe 18 Gas supply unit 20 Temperature control device 21 Temperature sensor 70 Control device 71 Control unit 72 Memory unit 72a Parameter data 200 First switching unit 201 Second switching unit 206 First temperature control unit 207 Second temperature control unit 208 Pipe 220 Pipe 222 Pipe 225 Pipe 227 Pipe 2000 First supply valve 2001 Second supply valve 2010 First return valve 2011 Second return valve

Claims (17)

a mounting table having a mounting surface on which a substrate is mounted, a flow path for flowing a temperature control medium formed therein, and an outlet port for discharging a heat transfer gas onto the mounting surface;
a gas supply unit that supplies the heat transfer gas to be discharged from the discharge port;
A measuring unit that measures the temperature of a temperature control medium flowing through the flow path;
a control unit that, when the temperature of the temperature control medium measured by the measurement unit changes by a predetermined temperature or more, controls the pressure of the heat transfer gas supplied from the gas supply unit so as to cancel out the temperature change of the substrate caused by the temperature change of the temperature control medium after a predetermined time has elapsed since the time when the temperature of the temperature control medium measured by the measurement unit has changed and a temperature change of the substrate placed on the placement surface has occurred due to the temperature change of the temperature control medium;
A substrate processing apparatus comprising: 2. The substrate processing apparatus of claim 1, wherein the control unit controls the pressure of the heat transfer gas supplied from the gas supply unit to be increased when the temperature of the temperature control medium changes to be higher by a predetermined temperature or more, and controls the pressure of the heat transfer gas supplied from the gas supply unit to be decreased when the temperature of the temperature control medium changes to be lower by a predetermined temperature or more. 3. The substrate processing apparatus of claim 1, wherein the control unit calculates a correction amount for the pressure of the heat transfer gas to correct the change in temperature of the substrate using a relational equation showing the relationship between the pressure of the heat transfer gas supplied from the gas supply unit and the temperature of the substrate, and controls the pressure of the heat transfer gas supplied from the gas supply unit to change by the correction amount after the predetermined time has elapsed from the timing of the change. The relational expression includes a parameter, and the method further includes a storage unit that stores parameter data in which values of the parameter in the relational expression are stored for each heat input amount of the plasma processing or each processing condition of the plasma processing,
4. The substrate processing apparatus according to claim 3, wherein the control unit identifies, from the parameter data, a parameter value corresponding to the heat input of the plasma processing being performed or the processing conditions of the plasma processing when the temperature of the temperature control medium measured by the measuring unit changes by a predetermined temperature or more, and determines a correction amount for the pressure of the heat transfer gas to correct the temperature change of the substrate using the relational equation to which the identified parameter value is applied. The substrate processing apparatus of any one of claims 1 to 4, wherein the control unit controls the pressure of the heat transfer gas supplied from the gas supply unit in accordance with the shape of a waveform of a temperature change when the temperature of the temperature control medium measured by the measuring unit changes by more than a predetermined temperature. The flow path and the temperature control medium are circulated, and a temperature control medium supply unit is further provided that switches between a temperature control medium having a first temperature and a temperature control medium having a second temperature higher than the first temperature and supplies the temperature control medium to the flow path;
The control unit controls the pressure of the heat transfer gas supplied from the gas supply unit when the temperature of the temperature control medium measured by the measurement unit changes from the first temperature by a predetermined temperature or more while the temperature control medium at the first temperature is being supplied from the temperature control medium supply unit to the flow path, and when the temperature of the temperature control medium measured by the measurement unit changes from the second temperature by a predetermined temperature or more while the temperature control medium at the second temperature is being supplied from the temperature control medium supply unit to the flow path, after the predetermined time has elapsed from the time when the temperature control medium was changed. The flow path and the temperature control medium are circulated, and a temperature control medium having a first temperature and a temperature control medium having a second temperature higher than the first temperature are mixed to a set temperature and supplied to the flow path,
The substrate processing apparatus of any one of claims 1 to 5, wherein when the temperature control medium mixed to reach the set temperature is supplied from the temperature control medium supply unit to the flow path, if the temperature of the temperature control medium measured by the measurement unit changes from the set temperature by a predetermined temperature or more, the control unit controls the pressure of the heat transfer gas supplied from the gas supply unit after the predetermined time has elapsed from the time of the change. 8. The substrate processing apparatus according to claim 1, wherein the predetermined time is determined by measuring a period during which a temperature change occurs in the substrate after a temperature change in the temperature control medium. A substrate processing apparatus as described in any one of claims 1 to 7, wherein the specified time is determined by calculation from a delay time dependent on a piping volume, the time required for heat transfer from the temperature control medium to the substrate, and the time required from issuing an instruction to change the pressure of the heat transfer gas to the actual change in pressure. a step of measuring a temperature of a temperature control medium flowing through a flow passage of a mounting table having a mounting surface on which a substrate is mounted, the flow passage being formed therein, and an outlet port for discharging a heat transfer gas onto the mounting surface;
when the measured temperature of the temperature control medium changes by a predetermined temperature or more, after a predetermined time has elapsed since the time of the change, during which a temperature change occurs in the substrate placed on the mounting surface due to the temperature change of the temperature control medium, controlling the pressure of the heat transfer gas discharged from the discharge port so as to cancel out the temperature change of the substrate due to the temperature change of the temperature control medium;
The substrate temperature compensation method includes: a mounting table having a mounting surface for mounting a substrate thereon and a flow path for flowing a temperature control medium therein;
A measuring unit that measures the temperature of a temperature control medium flowing through the flow path;
a control unit that, when the temperature of the temperature control medium measured by the measurement unit changes by a predetermined temperature or more, adjusts the thermal conductivity between the temperature control medium and the substrate placed on the placement surface after a predetermined time has elapsed since the time when the temperature of the temperature control medium measured by the measurement unit has changed, so as to cancel out the temperature change of the substrate caused by the temperature change of the temperature control medium.
A substrate processing apparatus comprising: 12. The substrate processing apparatus of claim 11, wherein the control unit controls the temperature control medium to increase the thermal conductivity between the temperature control medium and the substrate placed on the mounting surface when the temperature of the temperature control medium changes to be higher by a predetermined temperature or more, and controls the temperature control medium to decrease the thermal conductivity between the temperature control medium and the substrate placed on the mounting surface when the temperature of the temperature control medium changes to be lower by a predetermined temperature or more. the mounting table has an outlet formed on the mounting surface through which a heat transfer gas is discharged,
Further, a gas supply unit that supplies the heat transfer gas to be discharged from the discharge port is provided,
The substrate processing apparatus according to claim 11 , wherein the control unit controls a pressure of the heat transfer gas supplied from the gas supply unit. 14. The substrate processing apparatus of claim 13, wherein the control unit controls the pressure of the heat transfer gas supplied from the gas supply unit to be increased when the temperature of the temperature control medium changes to be higher by a predetermined temperature or more, and controls the pressure of the heat transfer gas supplied from the gas supply unit to be decreased when the temperature of the temperature control medium changes to be lower by a predetermined temperature or more. The substrate processing apparatus according to claim 11 , wherein the control unit controls a flow rate of the temperature control medium flowing through the flow path. 16. The substrate processing apparatus of claim 15, wherein the control unit controls the flow rate of the temperature control medium flowing through the flow path to be increased when the temperature of the temperature control medium changes to be higher by a predetermined temperature or more, and controls the flow rate of the temperature control medium flowing through the flow path to be decreased when the temperature of the temperature control medium changes to be lower by a predetermined temperature or more. The substrate processing apparatus of any one of claims 11 to 16, wherein the control unit adjusts the thermal conductivity from the flow path to the substrate placed on the placement surface in accordance with the shape of a waveform of a temperature change when the temperature of the temperature control medium measured by the measurement unit changes by a predetermined temperature or more.

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