JP2021034516A - Heat medium circulation system and control method thereof - Google Patents

Abstract

To provide a heat medium circulation system and a control method thereof that improve the uniformity of processing on a substrate.SOLUTION: A heat medium circulation system includes a member flow path formed on a mounting table on which a substrate is mounted, a switching unit that switches the direction of the flow of a heat medium flowing through the member flow path, a first flow path connecting one end of the member flow path and the switching unit, a second flow path connecting the other end of the member flow path and the switching unit, and a control unit that controls the switching unit, and the control unit repeatedly executes the steps of flowing the heat medium in the first direction in the order of the first flow path, the member flow path, and the second flow path, and flowing the heat medium in the second direction in the order of the second flow path, the member flow path, and the first flow path.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a heat medium patrol system and a control method for the heat medium patrol system.

For example, a substrate processing apparatus that performs a predetermined process on a substrate such as a wafer is known.

Patent Document 1 discloses a substrate mounting table on which a flow path for passing a temperature control medium is provided and a substrate to be processed is mounted while controlling the temperature.

Japanese Unexamined Patent Publication No. 2006-261541

On the one hand, the present disclosure provides a heat medium circulation system and a control method for the heat medium circulation system that improves the uniformity of processing on the substrate.

In order to solve the above problems, according to one aspect, a member flow path formed on a mounting table on which a substrate is placed, a switching unit for switching the direction of the flow of heat medium flowing through the member flow path, and the above-mentioned A first flow path connecting one end of the member flow path and the switching portion, a second flow path connecting the other end of the member flow path and the switching portion, a control unit for controlling the switching portion, and the like. The control unit includes a step of flowing a heat medium in the first direction in the order of the first flow path, the member flow path, and the second flow path, and the second flow path, the member flow path, and the member flow path. Provided is a heat medium circulation system that repeats a step of flowing a heat medium in a second direction in the order of a first flow path.

According to one aspect, it is possible to provide a heat medium circulation system and a control method of the heat medium circulation system that improve the uniformity of processing on the substrate.

An example of a configuration diagram of a heat medium circulation system according to the first embodiment. An example of a flowchart for explaining heat medium supply control to the base. The graph which shows an example of the temperature change of each point of a member flow path in a reference example. The graph which shows an example of the temperature change of each point of the member flow path in the 1st operation example. The graph which shows an example of the temperature change of each point of the member flow path in the 2nd operation example. The graph which shows an example of the temperature change of each point of the member flow path in the 3rd operation example. An example of a table showing the temperature of each point in the reference example and each operation example. An example of a configuration diagram of a heat medium circulation system according to a second embodiment.

Hereinafter, embodiments for carrying out the present disclosure will be described with reference to the drawings. In each drawing, the same components may be designated by the same reference numerals and duplicate description may be omitted.

The heat medium circulation system S according to the first embodiment will be described with reference to FIG. FIG. 1 is an example of a configuration diagram of a heat medium circulation system S according to a first embodiment, (a) shows an operation in a first operation mode, and (b) shows an operation in a second operation mode. .. In FIG. 1, the direction in which the refrigerant flows is indicated by a black arrow. Further, in the on-off valves (switching devices 53 and 54) described later, the valve open state is shown in black and the valve closed state is shown in white.

The heat medium circulation system S according to the first embodiment includes a processing device 1, a first chiller 2, a second chiller 3, a flow path 4, and switching devices 51 to 54 provided in the flow path 4. , And a control device 6.

The processing device 1 is a device that processes the wafer W. The wafer W is subjected to heat treatment, plasma treatment, UV treatment and other treatments. The processing of the wafer W includes all processing such as etching treatment, film forming treatment, cleaning treatment, treatment treatment, and ashing treatment.

The processing apparatus 1 has a processing container 10 and a mounting table 11 on which the wafer W is placed. The mounting table 11 has an electrostatic chuck 12, an adhesive layer 13, and a base 14. The electrostatic chuck 12 is formed of a dielectric material such as ceramic, and is arranged on the base 14 via an adhesive layer 13. The electrostatic chuck 12 has an electrode 12a and a heater 12b. By applying a voltage from a DC power source to the electrode 12a, the wafer W is electrostatically adsorbed on the electrostatic chuck 12. The wafer W can be heated by applying a voltage from an AC power source to the heater 12b. The energization of the electrodes 12a and the heater 12b is controlled by the control device 6. The adhesive layer 13 is provided between the electrostatic chuck 12 and the base 14, and fixes the electrostatic chuck 12 to the base 14. The base 14 is made of a metal such as aluminum and is supported by the support base 15. Inside the base 14, a member flow path 14c having one end side as an outflow port 14a and the other end side as an outflow port 14b is formed in a ring shape or a spiral shape. The support base 15 supports the base 14 inside the processing container 10.

Further, the processing device 1 may be configured as a plasma processing device. A high-frequency power source (not shown) that applies high-frequency power for plasma generation is connected to the base 14 via a matching device (not shown). With such a configuration, the mounting table 11 has a function as a lower electrode. Further, a gas supply source (not shown) for supplying a desired gas into the processing container 10 and a vacuum pump (not shown) for depressurizing the inside of the processing container 10 are connected to the processing container 10. Further, in the processing container 10, a shower head (not shown) that faces the mounting table 11 and functions as an upper electrode is provided above the mounting table 11. Plasma is generated between the shower head as the upper electrode and the mounting table 11 as the lower electrode.

The refrigerant (heat medium) flowing through the member flow path 14c may be, for example, a liquid such as cooling water or brine, or may be, for example, a gas such as a refrigerant gas.

The first chiller 2 adjusts the temperature of the refrigerant to a predetermined temperature. The first chiller 2 has a temperature adjusting unit (not shown) for adjusting the temperature of the refrigerant, a tank for storing the refrigerant (not shown), and a pump 21 for discharging the refrigerant. The refrigerant flowing into the first chiller 2 is adjusted to a predetermined temperature by a temperature adjusting unit such as a heat exchanger and stored in a tank. The pump 21 discharges the refrigerant adjusted to a predetermined temperature.

The second chiller 3 adjusts the temperature of the refrigerant to a predetermined temperature. The second chiller 3 has a temperature adjusting unit (not shown) for adjusting the temperature of the refrigerant, a tank for storing the refrigerant (not shown), and a pump 31 for discharging the refrigerant. The refrigerant that has flowed into the second chiller 3 is adjusted to a predetermined temperature by a temperature adjusting unit such as a heat exchanger, and is stored in the tank. The predetermined temperature in the second chiller 3 and the predetermined temperature in the first chiller 2 may be the same temperature or different temperatures. The pump 31 discharges the refrigerant adjusted to a predetermined temperature.

An adjusting mechanism (not shown) for adjusting the amount of refrigerant may be provided between the tank of the first chiller 2 and the tank of the second chiller 3. For example, the adjusting mechanism can allow the refrigerant to flow from one tank to the other when the stored amount of one tank exceeds a predetermined amount.

The flow path 4 connects the member flow path 14c of the mounting table 11, the first chiller 2, and the second chiller 3, and is configured to allow the refrigerant to flow. The flow path 4 has flow paths 4a to 4h. Each of the flow paths 4a to 4h included in the flow path 4 is formed by piping.

The flow path 4a connects the discharge side of the first chiller 2 and the first port of the switching device 51. The flow path 4b connects the common port of the switching device 51 and the outflow port 14a of the base 14. The flow path 4c connects the outflow port 14b of the base 14 and the common port of the switching device 52. The flow path 4d connects the first port of the switching device 52 and the inflow side of the first chiller 2. The flow path 4e connects the discharge side of the second chiller 3 and the second port of the switching device 52. The flow path 4f connects the second port of the switching device 51 and the inflow side of the second chiller 3. The flow path 4g communicates between the flow path 4a and the flow path 4d as a bypass line. A switching device 53 is provided in the flow path 4g. The flow path 4h communicates between the flow path 4e and the flow path 4f as a bypass line. A switching device 54 is provided in the flow path 4h.

The switching device 51 is a three-way valve having a common port, a first port, and a second port. The switching device 51 has a first state in which the common port and the first port communicate with each other (see FIG. 1A) and a second state in which the common port and the second port communicate with each other (see FIG. 1B). ) And can be switched. The state of the switching device 51 is controlled by the control device 6 described later.

The switching device 52 is a three-way valve having a common port, a first port, and a second port. The switching device 52 has a first state in which the common port and the first port communicate with each other (see FIG. 1A) and a second state in which the common port and the second port communicate with each other (see FIG. 1B). ) And can be switched. The state of the switching device 52 is controlled by the control device 6 described later.

The switching device 53 is an on-off valve that switches the opening and closing of the flow path 4g. The opening and closing of the switching device 53 is controlled by a control device 6 described later.

The switching device 54 is an on-off valve that switches the opening and closing of the flow path 4h. The opening and closing of the switching device 54 is controlled by a control device 6 described later.

The control device 6 switches the mode of the heat medium circulation system S by controlling the operation of the pumps 21 and 31 and the switching of the switching devices 51 to 54.

As shown in FIG. 1A, in the first operation mode, the control device 6 switches the switching device 51 to the first state in which the common port and the first port communicate with each other, and sets the switching device 52 as the common port. It switches to the first state in which the first port communicates, closes the switching device 53, and opens the switching device 54. Further, the control device 6 operates the pumps 21 and 31. As a result, the refrigerant discharged from the first chiller 2 is supplied to the outflow port 14a of the base 14 via the flow path 4a, the switching device 51, and the flow path 4b. In the member flow path 14c of the base 14, the refrigerant flows from the outflow port 14a toward the outflow port 14b, and heat is exchanged between the refrigerant and the base 14. The refrigerant discharged from the outflow port 14b is supplied to the inflow side of the first chiller 2 via the flow path 4c, the switching device 52, and the flow path 4d. Further, the refrigerant discharged from the second chiller 3 flows through the flow path 4e, the flow path 4h, and the flow path 4f, and is supplied to the inflow side of the second chiller 3.

As shown in FIG. 1 (b), in the second operation mode, the control device 6 switches the switching device 51 to the second state in which the common port and the second port communicate with each other, and sets the switching device 52 as the common port. It switches to the second state in which the second port communicates, opens the switching device 53, and closes the switching device 54. Further, the control device 6 operates the pumps 21 and 31. As a result, the refrigerant discharged from the second chiller 3 is supplied to the outflow port 14b of the base 14 via the flow path 4e, the switching device 52, and the flow path 4c. In the member flow path 14c of the base 14, the refrigerant flows from the outflow port 14b toward the outflow port 14a, and heat is exchanged between the refrigerant and the base 14. The refrigerant discharged from the outflow port 14a is supplied to the inflow side of the second chiller 3 via the flow path 4b, the switching device 51, and the flow path 4f. Further, the refrigerant discharged from the first chiller 2 flows through the flow path 4a, the flow path 4g, and the flow path 4d, and is supplied to the inflow side of the first chiller 2.

As described above, in the heat medium circulation system S shown in FIG. 1, the control device 6 controls the switching devices 51 to 54, so that the refrigerant flows through the member flow path 14c of the base 14 without stopping the pumps 21 and 31. You can switch the direction of.

When switching from the first operation mode to the second operation mode, the control device 6 first opens the switching device 53, then switches the switching devices 51 and 52 to the second state, and then switches the switching device 54. Close. Further, when switching from the second operation mode to the first operation mode, the control device 6 first opens the switching device 54, then switches the switching devices 51 and 52 to the first state, and finally switches. Close device 53. As a result, the switching devices 51 to 54 can be switched without blocking the flow path from the discharge side to the inflow side of the pumps 21 and 31.

Next, the heat medium supply control to the base 14 in the heat medium circulation system S according to the first embodiment will be described with reference to FIG. FIG. 2 is an example of a flowchart for explaining the heat medium supply control to the base 14.

In step S101, the control device 6 flows the refrigerant in the first direction through the member flow path 14c of the base 14. Here, the first direction is, for example, a direction in which the outflow port 14a is used as the inflow port, the outflow port 14b is used as the outflow port, and the refrigerant flows from the outflow port 14a toward the outflow port 14b in the member flow path 14c. Specifically, the control device 6 controls the pumps 21 and 31 and the switching devices 51 to 54 to set the first operation mode shown in FIG. 1A.

In step S102, the control device 6 determines whether or not a predetermined switching time has elapsed. If the predetermined switching time has not elapsed (S102 / No), the process of the control device 6 repeats step S102. That is, the operation of flowing the refrigerant in the first direction is continued. When the predetermined switching time has elapsed (S102 · Yes), the process of the control device 6 proceeds to step S103.

Here, the switching time is preferably set to be longer than the time required for the refrigerant to flow from the switching device 51 through the flow path 4b, the member flow path 14c, and the flow path 4c to the switching device 52. Further, the switching time is longer than the time until the refrigerant discharged from the first chiller 2 or the second chiller 3 passes through the member flow path 14c and returns to the first chiller 2 or the second chiller 3 again. It may be set. This makes it possible to prevent the refrigerant in the member flow path 14c from continuing to reciprocate without returning to the first chiller 2 or the second chiller 3. The time required for the refrigerant to flow from the switching device 51 through the flow path 4b, the member flow path 14c, and the flow path 4c to the switching device 52 depends on the device configuration, but is, for example, about 1 to 2 seconds. ..

Further, the switching time is preferably set to be equal to or less than the time constant RC of the surface temperature of the mounting surface on which the wafer W of the electrostatic chuck 12 is mounted. Here, the time constant RC is a constant indicating that the surface temperature of the electrostatic chuck 12 is in a transient state, and specifically, is the product of the combined thermal resistance R and the combined heat capacity C.

Synthetic thermal resistance R is, for example, heat resistance due to the electrostatic chuck 12 _{R 1,} the thermal resistance due to the adhesive layer 13 _{R 2,} the thermal resistance _{R 3} by the flow path wall member passage 14c (base 14), the flow path wall ( _{It is the total of the thermal resistance R 4} (R = R ₁ + R ₂ + R ₃ + R ₄ ) due to the heat transfer from the base 14) to the refrigerant.

The combined heat capacity C is, for example, _{the total of the heat capacity C 1 by the electrostatic chuck 12, the heat capacity C 2} by the adhesive layer 13, and the heat _{capacity C 3} by the flow path wall (base 14) of the member flow path 14c (C = C _1). + C ₂ + C ₃ ).

In step S103, the control device 6 causes the refrigerant to flow in the second direction through the member flow path 14c of the base 14. Here, the second direction is opposite to the first direction. For example, the outflow port 14b is used as the inflow port, the outflow port 14a is used as the outflow port, and the outflow port 14b is used as the outflow port in the member flow path 14c. The direction is such that the refrigerant flows toward 14a. Specifically, the control device 6 controls the pumps 21 and 31 and the switching devices 51 to 54 to set the second operation mode shown in FIG. 1 (b).

In step S104, the control device 6 determines whether or not a predetermined switching time has elapsed. If the predetermined switching time has not elapsed (S104 / No), the process of the control device 6 repeats step S104. That is, the operation of flowing the refrigerant in the second direction is continued. When the predetermined switching time has elapsed (S104 · Yes), the process of the control device 6 proceeds to step S101.

Here, the switching time in step S104 is the time required for the refrigerant to flow from the switching device 52 through the flow path 4c, the member flow path 14c, and the flow path 4b to the switching device 51, similarly to the switching time in step S102. It is preferable to set the above. Further, the switching time in step S104 is preferably set to be equal to or less than the time constant RC of the surface temperature of the mounting surface on which the wafer W of the electrostatic chuck 12 is mounted, similarly to the switching time in step S102. The switching time in step S104 may be the same as or different from the switching time in step S102.

In this way, the control device 6 alternately switches the direction of the refrigerant flowing in the member flow path 14c every switching time.

Next, with respect to an example of the temperature change at each point 1 to 3 of the member flow path 14c in the heat medium circulation system S according to the first embodiment, FIGS. 4 to 7 are used while comparing with the reference example shown in FIG. I will explain.

Here, the simulation was performed using the member flow path 14c as one flow path. Point 1 indicates the surface temperature of the electrostatic chuck 12 located above the point near one outflow port 14a of the member flow path 14c, and point 2 indicates the surface temperature of one outflow port 14a and the other outflow port 14b of the member flow path 14c. The surface temperature of the electrostatic chuck 12 located above the midpoint with and is indicated, and the point 3 indicates the surface temperature of the electrostatic chuck 12 located above the point near the other outflow port 14b of the member flow path 14c. Further, in FIGS. 3 to 6, the horizontal axis represents time, and the vertical axis represents the temperature at points 1 to 3 on the surface of the electrostatic chuck 12.

FIG. 3 is a graph showing an example of a temperature change at each point of the member flow path 14c in the heat medium circulation system according to the reference example. Further, FIG. 3A shows a temperature change from the start of heat input, and FIG. 3B is an enlarged view of the range shown in the range A.

Here, the heat medium circulation system according to the reference example includes the same processing device 1 as the heat medium circulation system S according to the first embodiment. Further, the heat medium circulation system according to the reference example includes a chiller and a flow path for connecting the member flow path 14c of the mounting table 11 and the chiller so that the refrigerant can flow. That is, the heat medium circulation system according to the reference example does not switch the direction of the refrigerant flowing in the member flow path 14c, and the refrigerant flows in one direction in the member flow path 14c. Different from system S. Here, it is assumed that the refrigerant is flowing from the point 1 to the point 3. In other words, it is assumed that the refrigerant is flowing from the outflow port 14a toward the outflow port 14b.

Before the start of heat input by plasma generation, the temperature of each of the points 1 to 3 is substantially equal because the base 14 is cooled by the refrigerant. When the plasma generation is started, the heat of the plasma enters the points 1 to 3 on the surface of the electrostatic chuck 12 via the wafer W, and is cooled by the refrigerant flowing through the member flow path 14c of the base 14, and each point. The temperature in 1-3 increases toward a steady state. Here, the refrigerant absorbs heat from the base 14 while flowing from the outflow port 14a toward the outflow port 14b, and the refrigerant temperature rises. Therefore, in the steady state, the temperature at each of the points 1 to 3 on the surface of the electrostatic chuck 12 also increases from the point 1 to the point 3.

FIG. 4 is a graph showing an example of a temperature change at each point of the member flow path 14c in the first operation example of the heat medium circulation system S according to the first embodiment. Further, FIG. 4A shows a temperature change from the start of heat input, and FIG. 4B is an enlarged view of the range shown in the range B. In the first operation example, the direction of the refrigerant flowing in the member flow path 14c is alternately switched, with the switching time being 160 seconds, which is a time sufficiently longer than the time constant RC, from the start of heat input (start of plasma generation). Further, the switching time in step S102 and the switching time in step S104 are the same.

It is assumed that the refrigerant is flowing from point 1 to point 3 before the start of heat input. When the heat input is started (plasma generation is started), the refrigerant flows in the member flow path 14c while absorbing heat from the outflow port 14a toward the outflow port 14b. Therefore, the temperature at each of the points 1 to 3 on the surface of the electrostatic chuck 12 increases from the point 1 to the point 3.

When 160 seconds have passed from the start of heat input, the control device 6 switches the direction of the refrigerant flowing in the member flow path 14c (switching S1). The refrigerant flows in the member flow path 14c while absorbing heat from the outflow port 14b toward the outflow port 14a. As a result, the refrigerant is supplied from the point 3 side, so that the temperature at the point 3 decreases. On the other hand, since the refrigerant absorbed heat while flowing in the member flow path 14c is supplied to the point 1 side, the temperature at the point 1 rises.

When 160 seconds have passed since the previous switching, the control device 6 switches the direction of the refrigerant flowing in the member flow path 14c (switching S2). The refrigerant flows in the member flow path 14c while absorbing heat from the outflow port 14a toward the outflow port 14b. As a result, the refrigerant is supplied from the point 1 side, so that the temperature at the point 1 decreases. On the other hand, since the refrigerant absorbed heat while flowing in the member flow path 14c is supplied to the point 3 side, the temperature at the point 3 rises.

When 160 seconds have passed since the previous switching, the control device 6 switches the direction of the refrigerant flowing in the member flow path 14c (switching S3). After that, the control device 6 switches the direction of the refrigerant flowing in the member flow path 14c every time the switching time elapses.

FIG. 5 is a graph showing an example of a temperature change at each point of the member flow path 14c in the second operation example of the heat medium circulation system S according to the first embodiment. In the second operation example, the direction of the refrigerant flowing in the member flow path 14c is alternately switched with the switching time being 26 seconds, which is the time constant RC, from the start of heat input (start of plasma generation). Further, the switching time in step S102 and the switching time in step S104 are the same. In the second operation example, switching is performed in a transient state before the temperature of each of the points 1 to 3 becomes a steady state. The processing of the control device 6 is the same as that of the first operation example except that the switching time is different, and redundant description will be omitted.

FIG. 6 is a graph showing an example of a temperature change at each point of the member flow path 14c in the third operation example of the heat medium circulation system S according to the first embodiment. Further, FIG. 6A shows a temperature change from the start of heat input, and FIG. 6B is an enlarged view of the range shown in the range C. In the third operation example, the direction of the refrigerant flowing in the member flow path 14c is alternately switched, with the switching time being 5 seconds, which is a time sufficiently shorter than the time constant RC, from the start of heat input (start of plasma generation). Further, the switching time in step S102 and the switching time in step S104 are the same. In the third operation example, switching is performed in a transient state before the temperature of each of the points 1 to 3 becomes a steady state. Further, the switching time is longer than the time required for the refrigerant to flow from the switching device 51 through the flow path 4b, the member flow path 14c, and the flow path 4c to the switching device 52 (for example, about 1 to 2 seconds). is there. The processing of the control device 6 is the same as that of the first operation example except that the switching time is different, and redundant description will be omitted.

In the third operation example, the temperature at the intermediate point 2 is higher than the temperature at the points 1 and 3 on both ends. Here, in the early stage after switching the flow direction of the refrigerant, the temperature of the base 14 on the inlet side is high and the temperature of the base 14 on the outlet side is low. The refrigerant supplied to the member flow path 14c has a larger amount of heat absorption near the inlet than the amount of heat absorption at the intermediate point. Therefore, the temperature of the point 2 where the low-temperature refrigerant is supplied after passing near the high-temperature inlet is higher than that of the points 1 and 3 where the low-temperature refrigerant is supplied by alternately serving as the inlet.

FIG. 7 is an example of a table showing the temperatures at points 1 to 3 in the reference example and each operation example. Here, the temperature average value in one switching cycle is described before ±, and the temperature fluctuation (half value) in one switching cycle is described after ±.

Here, the difference between the maximum temperature and the minimum temperature among the temperatures at points 1 to 3 at a certain time is defined as an instantaneous temperature difference. Then, the maximum value of the instantaneous temperature difference is defined as ΔT _max . In the reference example and each operation example, the maximum value ΔT _max is shown in FIGS. 3 (b), 4 (b), 5 and 6 (b).

Further, among the temperature average values at points 1 to 3, the difference between the maximum temperature and the minimum temperature is defined as the variation of the temperature average values at points 1 to 3.

In the reference example (steady state) shown in FIG. 3B, the temperature at point 1 is 82.3 ° C, the temperature at point 2 is 85.2 ° C, and the temperature at point 3 is 87.7 ° C. _{Further, the maximum value ΔT max} of the instantaneous temperature difference between the points 1 to 3 is 5.4 ° C. as shown in FIG. 3 (b). Further, the variation in the temperature average value at each of the points 1 to 3 is 5.4 ° C. (= 87.7-82.3).

In the first operation example (switching time: 160 seconds) shown in FIG. 4 (b), the temperature at point 1 is 84.8 ± 2.7 ° C., the temperature at point 2 is 85.4 ± 0.4 ° C., and point 3 The temperature of is 84.8 ± 2.7 ° C. _{Further, the maximum value ΔT max} of the instantaneous temperature difference between the points 1 to 3 is 5.4 ° C. as shown in FIG. 4 (b). Further, the variation in the temperature average value at each of the points 1 to 3 is 0.6 ° C. (= 85.4-84.8).

In the second operation example (switching time: 26 seconds) shown in FIG. 5, the temperature at point 1 is 85.2 ± 1.3 ° C, the temperature at point 2 is 85.4 ± 0.1 ° C, and the temperature at point 3 is 85.4 ± 0.1 ° C. It is 85.2 ± 1.3 ° C. _{Further, the maximum value ΔT max} of the instantaneous temperature difference between the points 1 to 3 is 2.6 ° C. as shown in FIG. Further, the variation in the temperature average value at each of the points 1 to 3 is 0.2 ° C. (= 85.4-85.2).

In the third operation example (switching time: 5 seconds) shown in FIG. 6B, the temperature at point 1 is 85.0 ± 0.1 ° C, the temperature at point 2 is 85.7 ± 0.1 ° C, and point 3 The temperature of is 85.0 ± 0.1 ° C. _{Further, the maximum value ΔT max} of the instantaneous temperature difference between the points 1 to 3 is 0.9 ° C. as shown in FIG. 6 (b). Further, the variation in the temperature average value at each of the points 1 to 3 is 0.7 ° C. (= 85.7-85.0).

As described above, according to the heat medium circulation system S according to the first embodiment, the average value of the temperatures at each point on the surface of the electrostatic chuck 12 is obtained by alternately switching the directions of the refrigerant flowing through the member flow path 14c. Can be homogenized. That is, as shown in comparison between the reference example and the first to third operation examples, the variation in the temperature average value at each of the points 1 to 3 can be reduced. As a result, the average value of the temperatures at each point on the surface of the wafer W mounted on the mounting table 11 (electrostatic chuck 12) can be made uniform. Here, the processing applied to the wafer W depends on the surface temperature of the wafer W. Therefore, by making the average value of the temperature at each point on the surface of the wafer W uniform, it is possible to improve the in-plane uniformity of the treatment applied to the wafer W.

Further, according to the heat medium circulation system S according to the first embodiment, by making the switching time in step S102 and the switching time in step S104 the same, the variation in the temperature average value at each of the points 1 to 3 is reduced. be able to. As a result, the average value of the temperature at each point on the surface of the wafer W mounted on the mounting table 11 (electrostatic chuck 12) can be made uniform, and the in-plane uniformity of the treatment applied to the wafer W can be made uniform. Can be improved.

Further, according to the heat medium circulation system S according to the first embodiment, by setting the switching time for switching the direction of the refrigerant to the time constant RC or less, the transient state before the temperature at each point 1 to 3 becomes a steady state. Can be maintained, and the temperature difference between each of the points 1 to 3 can be reduced. That is, as shown in comparison between the reference example and the second to third operation examples, the maximum value ΔT _max of the instantaneous temperature difference between the points 1 to 3 can be reduced. As a result, the in-plane uniformity of the temperature of the surface of the wafer W mounted on the mounting table 11 (electrostatic chuck 12) can be improved.

Further, as shown in the third embodiment, by setting the switching time to 5 seconds, the temperature fluctuation (± 0.1 ° C. in the third operation example) in one switching cycle at each of the points 1 to 3 is set to the first to first. It can be made even smaller than the two operation examples. Further, the maximum value ΔT _max of the instantaneous temperature difference can be further reduced.

The heat medium circulation system S only needs to have a function of switching the direction of the refrigerant flowing through the member flow path 14c of the mounting table 11 (base 14), and the number of chillers 2 and 3 and the configuration of the flow path 4 are sufficient. The configurations of the switching devices 51 to 54 are not limited to the configurations shown in FIG.

The heat medium circulation system S has been described as operating the pumps 21 and 31 together in the first operation mode, but the present invention is not limited to this, and the pump 31 may be stopped. In this configuration, the heat medium circulation system S does not have to have the flow path 4h and the switching device 54. Further, the heat medium circulation system S has been described as operating the pumps 21 and 31 together in the second operation mode, but the present invention is not limited to this, and the pump 21 may be stopped. In this configuration, the heat medium circulation system S does not have to have the flow path 4g and the switching device 53. In this way, in the heat medium circulation system S, the control device 6 controls the switching devices 51, 52 and the pumps 21, 31 to change the direction of the refrigerant flowing through the member flow path 14c of the base 14. ..

The heat medium circulation system S according to the second embodiment will be described with reference to FIG. FIG. 8 is an example of a configuration diagram of the heat medium circulation system S according to the second embodiment, (a) shows the operation in the first operation mode, and (b) shows the operation in the second operation mode. .. In FIG. 8, the direction in which the refrigerant flows is indicated by a black arrow.

The heat medium circulation system S according to the second embodiment includes a processing device 1, one chiller 2, a flow path 4, a switching device 55 to 58 provided in the flow path 4, and a control device 6. ing.

The flow path 4 is configured to connect the member flow path 14c of the mounting table 11 and the chiller 2 so that the refrigerant can flow through the flow path 4. The flow path 4 has flow paths 4i to 4p. Each flow path 4i to 4p included in the flow path 4 is formed by piping.

The flow path 4i connects the discharge side of the chiller 2 and the common port of the switching device 55. The flow path 4j connects the first port of the switching device 55 and the first port of the switching device 56. The flow path 4k connects the common port of the switching device 56 and the outflow port 14a of the base 14. The flow path 4l connects the outflow port 14b of the base 14 and the common port of the switching device 57. The flow path 4m connects the first port of the switching device 57 and the first port of the switching device 58. The flow path 4n connects the common port of the switching device 58 and the inflow side of the chiller 2. The flow path 4o connects the second port of the switching device 55 and the second port of the switching device 57. The flow path 4p connects the second port of the switching device 56 and the second port of the switching device 58.

The switching devices 55 to 58 have a common port, a first port, and a second port. The switching device 51 has a first state in which the common port and the first port communicate with each other (see FIG. 8A) and a second state in which the common port and the second port communicate with each other (see FIG. 8B). ) And can be switched. The state of the switching devices 55 to 58 is controlled by the control device 6.

The control device 6 switches the mode of the heat medium circulation system S by controlling the switching of the switching devices 55 to 58.

As shown in FIG. 8A, in the first operation mode, the control device 6 switches the switching devices 55 to 58 to the first state in which the common port and the first port communicate with each other, and operates the pump 21. .. As a result, the refrigerant discharged from the chiller 2 is supplied to the outflow port 14a of the base 14 via the flow path 4i, the switching device 55, the flow path 4j, the switching device 56, and the flow path 4k. In the member flow path 14c of the base 14, the refrigerant flows from the outflow port 14a toward the outflow port 14b, and heat is exchanged between the refrigerant and the base 14. The refrigerant discharged from the outflow port 14b is supplied to the inflow side of the first chiller 2 via the flow path 4l, the switching device 57, the flow path 4m, the switching device 58, and the flow path 4n.

As shown in FIG. 1 (b), in the second operation mode, the control device 6 switches the switching devices 55 to 58 to the second state in which the common port and the second port communicate with each other, and operates the pump 21. .. As a result, the refrigerant discharged from the chiller 2 is supplied to the outflow port 14b of the base 14 via the flow path 4i, the switching device 55, the flow path 4o, the switching device 57, and the flow path 4l. In the member flow path 14c of the base 14, the refrigerant flows from the outflow port 14b toward the outflow port 14a, and heat is exchanged between the refrigerant and the base 14. The refrigerant discharged from the outflow port 14a is supplied to the inflow side of the chiller 2 via the flow path 4k, the switching device 56, the flow path 4p, the switching device 58, and the flow path 4n.

In the heat medium circulation system S according to the second embodiment as well, the treatment applied to the wafer W is performed by making the average temperature value uniform, as in the heat medium circulation system S according to the first embodiment. In-plane uniformity can be improved.

Although the heat medium patrol system S has been described above, the present disclosure is not limited to the above-described embodiment and the like, and various modifications and improvements can be made within the scope of the gist of the present disclosure described in the claims. It is possible.

The processing apparatus 1 of the present disclosure includes a CVD (Chemical Vapor Deposition) apparatus, an ALD (Atomic Layer Deposition) apparatus, a Capacitively Coupled Plasma (CCP), an Inductively Coupled Plasma (ICP), a Radial Line Slot Antenna, and an Electron Cyclotron Resonance Plasma (ECR). , Helicon Wave Plasma (HWP) is applicable to any type.

Further, the present invention is not limited to the processing apparatus 1 that generates plasma, and may be applied to a substrate processing apparatus (for example, a thermal CVD apparatus) that does not use plasma for processing the wafer W.

Further, the refrigerant (heat medium) flowing through the member flow path 14c is not limited to a single-phase state such as a liquid or a gas, _{but a gas-liquid two-phase state in which an organic solvent, CO 2} or the like is a mixed state of a gas and a liquid. It may be. When the refrigerant is in a gas-liquid two-phase state, the chillers 2 and 3 of the heat medium circulation system S have a compressor, a condenser, and an expansion valve, and form a heat pump cycle in which the member flow path 14c is used as an evaporator. You may.

S Heat medium circulation system 1 Processing device 10 Processing container 11 Mounting table 12 Electrostatic chuck 12a Electrode 12b Heater 13 Adhesive layer 14 Base 14a, 14b Outflow port 14c Member flow path 15 Support table 2, 3 Chillers 21, 31 Pump 4, 4a-4p flow path 4b flow path (first flow path)
4c flow path (second flow path)
51-58 switching device (switching unit)
6 Control device (control unit)
W wafer

Claims (8)

A member flow path formed on a mounting table on which a substrate is mounted, and
A switching unit that switches the direction of the flow of the heat medium flowing through the member flow path, and
A first flow path connecting one end of the member flow path and the switching portion,
A second flow path connecting the other end of the member flow path and the switching portion,
A control unit that controls the switching unit is provided.
The control unit
A step of flowing the heat medium in the first direction in the order of the first flow path, the member flow path, and the second flow path,
The step of flowing the heat medium in the second direction in the order of the second flow path, the member flow path, and the first flow path is repeated.
Thermal medium patrol system. Switching from the step of flowing in the first direction to the step of flowing in the second direction and / or switching from the step of flowing in the second direction to the step of flowing in the first direction is performed.
The surface temperature of the above-mentioned stand is transient.
The heat medium circulation system according to claim 1. The switching time for switching from the step of flowing in the first direction to the step of flowing in the second direction and / or switching from the step of flowing in the second direction to the step of flowing in the first direction is
It is equal to or less than the time constant obtained based on the product of the thermal resistance and the heat capacity from the surface of the above-mentioned stand to the heat medium flowing through the member flow path.
The heat medium circulation system according to claim 1 or 2. The switching time for switching from the step of flowing in the first direction to the step of flowing in the second direction and the switching time for switching from the step of flowing in the second direction to the step of flowing in the first direction are the same. ,
The heat medium circulation system according to any one of claims 1 to 3. The switching time is
It is longer than the time for the heat medium to flow from the switching portion through the member flow path and again to the switching portion.
The heat medium circulation system according to claim 3 or 4. The control unit
A process of switching the direction of the flow of the heat medium flowing through the member flow path to a transient state, and
The step of repeating the step of flowing in the first direction and the step of flowing in the second direction are executed.
The heat medium circulation system according to any one of claims 1 to 5. When the temperature difference on the surface of the table described above becomes less than a predetermined threshold value, a step of repeating the step of flowing in the first direction and the step of flowing in the second direction is started.
The heat medium circulation system according to claim 6. A member flow path formed on a mounting table on which a substrate is mounted, and
A switching unit that switches the direction of the flow of the heat medium flowing through the member flow path, and
A first flow path connecting one end of the member flow path and the switching portion,
A second flow path connecting the other end of the member flow path and the switching portion,
A control method for a heat medium circulation system including a control unit for controlling the switching unit.
A step of flowing a heat medium in the order of the first flow path, the member flow path, and the second flow path,
The step of flowing the heat medium in the order of the second flow path, the member flow path, and the first flow path is repeated.
Control method of heat medium circulation system.

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