JP3829980B2 - Apparatus and method for adjusting the temperature of an object using a heat transfer fluid - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to an apparatus and method for adjusting the temperature of an object using a heat transfer fluid.
[0002]
[Prior art]
For example, in a process chamber for processing a semiconductor wafer in a plasma atmosphere, a heat transfer fluid having a controlled temperature is used to control the temperature of a table (hereinafter referred to as “susceptor”) on which the semiconductor wafer is placed. Is used. The heat transfer fluid is brought to an appropriate temperature by a temperature control device (for example, a chiller that cools the high temperature heat transfer fluid returning from the chamber) installed at a location away from the chamber, and is sent from there to enter the chamber. Circulates in the susceptor, then goes out of the chamber and returns to the temperature control device.
[0003]
Conventionally, as shown in FIG. 1, this type of temperature control apparatus measures the temperature T1 of the heat transfer fluid just discharged from this apparatus, and heat is measured so that the measured discharge temperature T1 becomes the set temperature SV. The amount of cooling or heating to the medium fluid is adjusted.
[0004]
[Problems to be solved by the invention]
According to the above-described conventional method for controlling the discharge temperature of the heat medium fluid to the set temperature, when the plasma processing is started in the process chamber and a thermal load (disturbance) is applied to the susceptor, the temperature of the susceptor increases greatly. It is difficult to suppress this. In more general terms, in the control of the discharge temperature of the heat medium fluid, when a thermal load is applied to the temperature control target, it is difficult to suppress the temperature change of the target sufficiently small.
[0005]
Further, according to the above discharge temperature control, the temperature of the temperature control object such as the susceptor greatly changes due to the effects of heat loss, thermal resistance, dead time, delay, etc. in the pipes and chambers existing outside the temperature control device. It will be.
[0006]
In addition, a method for detecting the temperature of the temperature control object itself and performing a control operation so as to set the temperature to a set temperature is generally known. However, since the temperature of the temperature control object is indirectly adjusted through the heat transfer fluid, the temperature of the temperature control object can be controlled even if the control operation is performed based only on the temperature of the temperature control object itself. It is difficult to reduce the fluctuation.
[0007]
Accordingly, an object of the present invention is to make it possible to suppress fluctuations in the temperature of the temperature control object sufficiently small in an apparatus for controlling the temperature of the temperature control object using a heat medium fluid.
[0008]
[Means for Solving the Problems]
According to one aspect of the present invention, an apparatus for adjusting the temperature of an object includes a cooling / heating device using a heat transfer device that cools or heats a heat transfer fluid supplied to the object, and the object. An object temperature sensor that detects the current temperature of the object, and a controller that performs a feedback control operation using the current object temperature from the object temperature sensor and outputs an operation amount for the cooling / heating device. In the feedback control operation, the controller adjusts the temperature of the heat transfer fluid so as to control the object temperature to a desired temperature.
[0009]
An apparatus for adjusting the temperature of an object using a heat transfer fluid according to another aspect of the present invention includes a cooling / heating device for cooling or heating the heat transfer fluid supplied to the object, and the heat transfer fluid. A heat medium temperature sensor for detecting a current temperature of the object, an object temperature sensor for detecting a current temperature of the object, a current heat medium temperature from the heat medium temperature sensor, and a current object from the object temperature sensor A controller that performs a feedback control operation using the object temperature and outputs an operation amount for the cooling / heating device. In the feedback control operation, the controller determines a target temperature of the heat medium temperature so as to control the object temperature to a desired temperature, and controls the heat medium temperature to the determined target temperature. The operation amount is determined.
[0010]
According to this temperature control device, not only the temperature of the heat transfer fluid but also the temperature of the object is detected, and the temperature of the heat transfer fluid is controlled by using both temperatures, thereby reducing the temperature of the object. Fluctuations are suppressed to a small level, and control can be made more nearly constant.
[0011]
In a preferred embodiment, the cooling / heating device is adapted to cool or heat the heat transfer fluid using a thermoelectric conversion device. By using the thermoelectric conversion device, the size of the cooling / heating device can be reduced, and the distance between the cooling / heating device and the object can be shortened to reduce the amount of the heat transfer fluid, and the thermoelectric conversion device. Since its own responsiveness and temperature control accuracy are high, high controllability is obtained as a result.
[0012]
In a preferred embodiment, before starting the feedback control operation, the controller holds a numerical value related to a magnitude of a heat load to be externally applied to the object during the feedback control operation. A numerical value is used to determine an initial value of the manipulated variable according to the magnitude of the thermal load, and when the feedback control operation is started, the determined initial value is initially output. Yes.
[0013]
Thereby, control suitable for the magnitude | size of a heat load can be performed, and the application to various control systems from which the heat load added to a target object differs is attained.
[0014]
In a preferred embodiment, before starting the feedback control operation, the controller stably maintains the object temperature at the desired temperature in a state where no external heat load is applied to the object. When the idle value related to the magnitude of the operation amount necessary for the input is input and the initial value is determined, the initial value is adjusted using not only the size of the thermal load but also the idle value. Yes.
[0015]
If the various conditions such as the heat capacity and thermal conductivity of each part of the control system are different, the idle value will be different. By adjusting the initial value using the previously determined idle value as described above, application to various control systems with different conditions becomes possible.
[0016]
In a preferred embodiment, the controller calculates a current temperature difference between the object temperature and the heat medium temperature in the feedback control operation, and uses the calculated current temperature difference to calculate the desired temperature. The target temperature of the heat medium temperature is determined by dynamically correcting the temperature.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described. The following embodiment is an example of the case where the present invention is implemented for the purpose of controlling the temperature of a susceptor for holding a semiconductor wafer in a process chamber for processing semiconductor wear in a plasma atmosphere. The application object of the invention is not limited to this, and the present invention can be implemented in various other applications.
[0018]
FIG. 2 shows the overall configuration of this embodiment.
[0019]
A chiller 1 for cooling the heat transfer fluid is disposed, for example, at a place of 1 to several meters from the process chamber 4. A heat transfer fluid whose temperature is controlled by the chiller 1 is discharged from the chiller 1 and supplied to the process chamber 4 through the pipe 2. As the heat transfer fluid, for example, water, ethylene glycol, or Fluorinert (registered trademark) can be used. The heat transfer fluid that has entered the process chamber 4 circulates inside the susceptor 5 and adjusts the temperature of the susceptor 5. In the process chamber 4, when a semiconductor wafer placed on the susceptor 5 is processed, a plasma is generated, and heat is applied to the susceptor 5 from the plasma. At that time, the heat transfer fluid takes heat from the susceptor 5, cools it, and exits the process chamber 4 at a high temperature. The high-temperature heat transfer fluid returns to the chiller 1 through the pipe 3.
[0020]
A chiller 6 is provided in the chiller 1 to cool the returned high-temperature heat transfer fluid. For the cooler 6, for example, a thermoelectric conversion device that is a heat pump using a Peltier effect of a semiconductor is used (but not necessarily). This thermoelectric conversion device is composed of a large number of pairs of an n-type semiconductor chip and a p-type semiconductor chip that are electrically connected in a π shape. This thermoelectric conversion device is a plate-shaped device in which a large number of pairs are electrically connected directly and arranged on a two-dimensional plane, and when current is passed through it, heat is absorbed by the main surface on one side. However, it operates to release heat on the main surface on the opposite side. When the direction of the current flowing through the thermoelectric conversion device is reversed, the direction in which the thermoelectric conversion device moves heat is also reversed.
[0021]
The cooler 6 absorbs heat from the heat transfer fluid flowing from the pipe 3 to the pipe 2 on one main surface of the plate-shaped thermoelectric conversion device, and on the opposite main surface, the pipe Heat is released to the cooling water coming from 7 and going out to the pipe 8.
[0022]
When the cooler 6 is configured using the thermoelectric conversion device as described above, the size of the chiller 1 can be considerably reduced as compared with the case where the cooler 6 is configured with a refrigerant circuit having a general compressor. Since the distance from the process chamber 4 can be shortened to reduce the amount of the heat transfer fluid, and the response speed and temperature control accuracy of the cooler 6 itself are improved, control with better performance is possible.
[0023]
Associated with the chiller 1 is a controller 9 that controls the cooling capacity of the cooler 6 mainly by controlling the current that flows through the thermoelectric conversion device of the cooler 6, and thereby the heat medium fluid exiting the cooler 6. Control the temperature to an appropriate value. The controller 9 inputs a detection signal 11 indicating a current temperature (discharge temperature) T1 of the heat transfer fluid when discharged from the chiller 1 from a discharge temperature sensor 10 disposed in the vicinity of the heat transfer fluid discharge port of the chiller 1. To do. The controller 9 also receives a detection signal 13 indicating the current susceptor temperature Ts from a susceptor temperature sensor 12 that detects the temperature of the susceptor 5 in the process chamber 4. Further, the controller 9 receives an operation signal 15 indicating an on / off signal of the main switch and an output power level thereof from a radio frequency (RF) power supply device 14 for generating high frequency plasma in the process chamber 4. Based on these inputs, the controller 9 performs a control operation as described below. The controller 9 is constituted by, for example, a programmed computer.
[0024]
FIG. 3 shows the flow of the overall control operation performed by the controller 9.
[0025]
As shown in FIG. 3, the controller 9 starts a control operation in step S <b> 1, but at this initial point, in the process chamber 4, the main switch of the RF power supply device 14 is off and the process in the chamber 4 is Not started (hereinafter referred to as “idle state”). In this initial idle state, the controller 9 first performs follow-up control to cope with a change in the set temperature SV in step S2 (S2). As a result of this follow-up control, a steady state is established in which the susceptor temperature Ts is set to the set temperature SV. Thereafter, the controller 9 waits for the process to be started in the process chamber 4 while maintaining the steady state (S3). When the chamber process starts (for example, when the on / off signal of the main switch of the RF power supply device 14 indicates turn-on) (Yes in S3), the controller 9 proceeds to step S4 and enters the additional value control, and the inside of the chamber 4 The susceptor temperature Ts is controlled to be constant by overcoming disturbances such as a heat load caused by plasma generation in the case.
[0026]
By the way, in the chamber process, the following operation is repeatedly performed a number of times, with one operation as one cycle. At the start of the operation of one cycle, the output power level of the RF power supply device 14 is substantially zero and plasma is not generated (hereinafter referred to as “RF-OFF” state). In this “RF-OFF” state, a new semiconductor wafer is placed in the process chamber 4 and placed on the susceptor 5. Next, the output power level of the RF power supply 14 is increased to a specified wattage value, and plasma is generated in the process chamber 4 (hereinafter referred to as “RF-ON” state), thereby The semiconductor wafer is subjected to predetermined processing. After this “RF-ON” state continues for a certain time, the state in the chamber 4 is switched again to the “RF-OFF” state, and the processed semiconductor wafer is carried out of the process chamber 4. This completes this one-cycle operation. The operation as described above is repeated many times during one chamber process, whereby a large number of semiconductor wafers are sequentially processed in the chamber 4.
[0027]
While the above chamber process continues, the controller 9 continues the additional value control in step S4. If the set temperature SV is changed halfway (at this time, the chamber process is temporarily terminated) (Yes in S5), the controller 9 stops the additional value control and returns to step S2 again to perform the follow-up control described above. Then, the control is started again, and when the chamber process is restarted, the additional value control is performed again.
[0028]
When the chamber process ends (for example, when the on / off signal of the main switch of the RF power supply device 14 indicates turn-off) (Yes in S6), the controller 9 ends the control operation (S7).
[0029]
FIG. 4 shows in more detail the follow-up control procedure in step S2 performed in the first idle state during the overall control described above. FIG. 5 shows a control block diagram for feedback temperature control performed in the follow-up control (the feedback temperature control performed in the follow-up control described later is also performed by using the function of this block diagram. ) Further, FIG. 6 shows an example of a change curve of the discharge temperature T1 and the susceptor temperature Ts by the follow-up control (note that the temperature scale on the vertical axis shows the relative temperature with the set temperature SV being 0 ° C.).
[0030]
As shown in FIG. 4, when the tracking control is started (S11), the controller 9 first performs feedback temperature control (discharge temperature control) based only on the discharge temperature T1 (S12). This discharge temperature control is performed in a state where the switch 207 is opened and the offset value output from the offset unit 208 is initially set to zero in the block diagram of FIG. Here, blocks 201 to 203 and 206 to 208 are arithmetic processes performed by the controller 9, block 204 is a transfer function of the cooler 6, and block 205 is a transfer function of the susceptor 5. Further, the suffix n attached to the variable in FIG. 5 indicates the number of times of sampling when the control calculation is digitally processed. However, it goes without saying that an analog controller that performs time-continuous computation may be used in place of such a digital controller that performs time-discrete sampling. In this embodiment, as a method of feedback temperature control, I-PD control is used as indicated by a block 203 in FIG. However, the I-PD control is merely an example for explanation, and other control methods can be used.
[0031]
In this discharge temperature control, as shown in FIG. 5, the controller 9 has a deviation e between the detected discharge temperature T1 and a set temperature SV as its target temperature (since the offset value is zero, SV = SV *). (202, 202), I-PD calculation is performed on the deviation e (203), and the power of the thermoelectric conversion device of the cooler 6 (204) is manipulated according to the calculation result. Thereby, the discharge temperature T1 is controlled so as to substantially coincide with the set temperature SV as in a section A from time t0 seconds to t1 shown in FIG. On the other hand, although the susceptor temperature Ts changes so as to follow the discharge temperature T1, it has a slight temperature difference with the discharge temperature T1, and thus does not coincide with the set temperature SV.
[0032]
Referring to FIG. 4 again, when the discharge temperature T1 satisfies the predetermined ready condition (for example, stays stably within a range near the set temperature SV for a predetermined time) by the discharge temperature control in step S12 described above. (Yes in S13), the controller 9 determines that the discharge temperature T1 has reached a steady state (S14). The determination is made at time B (t1) in FIG. 6, for example. At the time B when the determination is made, the controller 9 calculates a temperature difference −ΔT (= T1−Ts) between the susceptor temperature Ts and the discharge temperature T1 in the steady state (S15). Then, the controller 9 adds the temperature difference −ΔT as an offset value to the set temperature SV. After time B, the added value (= SV−ΔT) is used as the new target temperature SV * of the discharge temperature T1 (S16), and the I-PD control of FIG. 4 is further executed (S17). The operation in steps S15 to S17 will be described with reference to the block diagram of FIG. 5. First, the switch 207 is closed at time B, and the temperature difference −ΔT (= T1−Ts) at time B is input to the offset unit 208 and stored. Subsequently, the switch 207 is immediately opened, and thereafter, with the switch 207 opened, the offset value −ΔT at time B held in the offset unit 208 is added to the set temperature SV to obtain the target temperature SV *. The discharge temperature T1 is subjected to I-PD control so as to coincide with the target temperature SV *. This control operation means that the susceptor temperature Ts is indirectly controlled to coincide with the set temperature SV. As a result, the susceptor temperature Ts is controlled to the set temperature SV as in the curve after time B shown in FIG.
[0033]
Referring to FIG. 4 again, if the susceptor temperature Ts satisfies a predetermined ready condition (for example, stays stably within a range near the set temperature SV for a predetermined time) by the discharge temperature control in step S17 ( In S18, the controller 9 determines that the susceptor temperature Ts has reached a steady state (S19). This determination is made, for example, at time C (t2) shown in FIG.
[0034]
If so, the controller 9 calculates the difference between the output value of the controller 9 in the steady state (the amount of operation to the cooler 6) (hereinafter referred to as the idle value) and a predetermined standard output value. The calculated output difference is stored (S19-2). Here, the standard output value is a standard control system condition (cooling water temperature, air temperature, and control system such as the cooler 6, the pipes 2, 3, and the susceptor 5) which is a premise for designing the controller 9. This is an output value that is output from the controller 9 when the susceptor temperature Ts is in a steady state when the discharge temperature control described above is performed under various characteristics of the constituent elements, etc. . This standard output value is correct only under the standard control system conditions described above. Therefore, the difference between the idle value calculated in step S19-2 and the standard output value means an excess or deficiency in the output value of the controller 9 under actual control system conditions. This excess / deficiency amount is stored, and is used for correcting excess / deficiency of the output value of the controller 9 in the subsequent value control.
[0035]
Subsequently, the controller 9 advances the control to step S3 shown in FIG. 3 in step S20 and waits for the process in the process chamber 4 to start (while waiting, the discharge temperature control in step S17 in FIG. continue).
[0036]
In the flow of the follow-up control in FIG. 4 described above, if the temperature difference detected in step S15 is inappropriate or cannot be settled to the set temperature SV due to disturbance after detection and cannot be set to the set temperature SV, the subsequent steps In the discharge temperature control in step S17, the susceptor temperature Ts is examined while finely adjusting the target temperature of the discharge temperature T1 from time to time (for example, at intervals of 30 seconds) so that the susceptor temperature Ts is set to the set temperature SV. Repeat the fine adjustment of the target temperature.
[0037]
When the follow-up control is completed, the controller 9 determines that the process of the process chamber 4 has started in response to the turn-on of the main switch of the RF power supply device 14 as already described with reference to FIG. (Yes in S3), the additional value control in step S4 is started, and the additional value control is continued while the chamber process is performed.
[0038]
FIG. 7 shows in further detail the flow of additional value control performed during the chamber process. The control function of FIG. 5 described above is also used in feedback temperature control performed in the additional value control. Further, FIG. 8 shows an example of a change curve of the susceptor temperature Ts by additional value control (note that the temperature scale indicates a relative temperature with the set temperature SV being 0 ° C.).
[0039]
As shown in FIG. 7, the controller 9 starts the additional value control in response to the start of the chamber process (S21), but at that time, the output power level of the RF power supply 14 is substantially zero. The state of the chamber 4 is in the “RF-OFF” state. This first “RF-OFF” state corresponds to the section C of the temperature 0 (= SV) at the left end in the curve of FIG. In this state, the controller 9 examines the output power level of the RF power supply device 14 and waits for the state of the chamber 4 to be switched to the “RF-ON” state (S22). When the output power level of the RF power supply 14 rises to the specified wattage value and the “RF-ON” state starts (Yes in S22) (time t3 in FIG. 8), the controller 9 performs the RF-ON region process in step S23. Thereafter, while the “RF-ON” state continues (section D in FIG. 8), the RF-ON region processing is continued. In this RF-ON region process, temperature control is performed using both the discharge temperature T1 and the susceptor temperature Ts, as will be described later. Thereafter, when the state of the chamber 4 returns to the “RF-OFF” state (Yes in S24) (time t5 in FIG. 8), the controller starts the RF-OFF area control in Step S25, and thereafter, “RF-OFF ”State continues (the second section C in FIG. 8), the RF-OFF region processing is continued. In this RF-OFF region process, as will be described later, in principle, the discharge temperature control using only the discharge temperature T1 is performed in the same manner as the follow-up control method shown in FIG. Thereafter, in synchronization with the repetition of “RF-ON” and “RF-OFF” of the RF power supply device 14, the above-described RF-ON region processing of Step 23 and RF-OFF region processing of Step S 25 are also repeatedly executed. become.
[0040]
The RF-ON region process in step S23 in FIG. 7 is performed in a state where the switch 207 is closed in the block diagram shown in FIG. This is I-PD control using both the discharge temperature T1 and the susceptor temperature Ts. That is, as shown in FIG. 5, the temperature difference between the current discharge temperature T1 and the current susceptor temperature Ts is added to the set temperature SV as an offset value (201), and the added value is the current value relative to the discharge temperature T1. Target temperature SV *. The temperature difference (offset value) between the current discharge temperature T1 and the current susceptor temperature Ts changes every moment, and the target temperature SV * is also changed every moment accordingly. In this way, the target temperature SV * is dynamically determined according to the temperature difference between the current discharge temperature T1 and the susceptor temperature Ts. Then, a deviation e between the dynamic target temperature SV * and the current discharge temperature T1 is calculated (202), an I-PD calculation is performed on the deviation e, and the calculation result is an operation amount ( The output value of the controller 9) is added to the cooler 6.
[0041]
On the other hand, the RF-OFF region processing in step S25 of FIG. 7 is performed in the state where the switch 207 is opened in the block diagram of FIG. Is output. This is the same as the I-PD control in step S16 in the follow-up control shown in FIG.
[0042]
Hereinafter, the RF-ON area process and the RF-OFF area process during the additional value control described above will be described in more detail.
[0043]
FIG. 9 shows the flow of RF-ON area processing in detail. FIG. 10 shows in detail the flow of the initial output process performed at the beginning of the RF-ON area process.
[0044]
As shown in FIG. 9, when the controller 9 starts the RF-ON region processing (S31), first, the controller 9 has an appropriate control system condition, a set temperature SV, and a heat load due to plasma generation. An initial output is determined and output (S32). In this initial output processing, as shown in FIG. 10, the controller 9 first uses the predetermined initial output derivative F to output the output power level of the RF power supply device 14 at this time (this is applied to the susceptor 5 when plasma is generated). A standard initial output suitable for the set temperature SV is calculated (corresponding to the magnitude of the thermal load to be applied) (S42). Here, the initial output derivative F is a function of the output power level of the RF power supply device 14 and the set temperature SV, and is the optimum of the initial output in the RF-ON region processing under the standard control system conditions described above. The value (standard initial output: experimentally obtained at the design stage of the controller 9) is shown. The initial output derivative F is, for example, a linear function of the output power level of the RF power supply device 14, and the slope and intercept of the linear function are linear polynomials of the set temperature SV, respectively. It can be mounted on the controller 9 in the form of a lookup table or a subroutine. After obtaining the standard initial output in this way, the controller 9 next reads the output difference between the idle value stored in step S19-2 of the follow-up control of FIG. 4 and the standard output, and this output difference is read as the standard initial output. To correct the excess and deficiency of the standard initial output, and output the corrected initial output value (S43). As a result, the controller 9 outputs an appropriate initial output value that matches the actual control system conditions.
[0045]
Referring again to FIG. 9, as soon as the initial output is output, the controller 9 increases the gain of the I-PD control from the initial value so that the response of the I-PD control of the block 203 shown in FIG. After slightly reducing (S33), the switch 207 shown in FIG. 5 is closed, and I-PD temperature control using both the discharge temperature T1 and the susceptor temperature Ts is performed (S34). Here, the reason why the response of the I-PD control is made slightly dull is that due to the poor thermal conductivity of the susceptor 5, it takes a certain time until the result of the initial output appears at the susceptor temperature Ts. This is to prevent the susceptor 5 from being overcooled because the I-PD control is too effective during this period.
[0046]
Thereafter, as shown in the sections t3 to t4 and the sections t6 to t7 in FIG. 8, the susceptor temperature Ts is disturbed and slightly rises due to the generation of plasma, but the effect of the I-PD control appears and the susceptor temperature Ts repels. Turn down. At the peak time when the susceptor temperature Ts changes from rising to falling (time t4, t7 in FIG. 8) (Yes in S35), the controller 9 slightly sets the response of the I-PD control blunted in step S33 to an initial value. The gain of the I-PD control is slightly increased so as to return to the direction (S36), the set temperature SV is shifted to the peak value of disturbance of the susceptor temperature Ts (Tsp in FIG. 8), and the above-described discharge is performed. The I-PD temperature control using both the temperature T1 and the susceptor temperature Ts is continued (S37). Here, the reason why the responsiveness of the I-PD control is slightly returned to the initial value is that the set temperature SV is quickly reached by increasing the responsiveness. The reason why the set temperature SV is shifted to the peak value of disturbance of the susceptor temperature Ts (Tsp in FIG. 8) is that the susceptor temperature Ts that has already risen is increased rather than lowered to the original set temperature SV again. This is because it is preferable to keep the peak value at a later peak value constant in order to control the quality of the semiconductor wafer being processed in the chamber 4 to be constant. Thereafter, the control in step S37 continues until the state of the chamber 4 is switched to the “RF-OFF” state.
[0047]
When the state of the chamber 4 is switched to the “RF-OFF” state (at time of about 220 seconds and 470 seconds in FIG. 8), the controller 9 ends the above-described RF-ON region processing and starts the RF-OFF region processing. To do.
[0048]
FIG. 11 shows the flow of the RF-OFF area process in detail.
[0049]
As shown in FIG. 11, when starting the RF-OFF region processing (S55), the controller 9 resets the integral (I) element of the I-PD calculation accumulated in the RF-ON region processing to zero (S52). Then, the gain of I-PD control, which was slightly smaller than the initial value in the RF-ON region processing, is returned to the initial value (S53). After that, the controller 9 again uses the target temperature SV * (= SV−ΔT) of the discharge temperature T1 used in step S16 of the tracking control before the start of the chamber process shown in FIG. In the same manner as described above, the susceptor temperature Ts is indirectly controlled to the set temperature SV.
[0050]
The RF-OFF region processing continues until the state of the chamber 4 becomes the “RF-ON” state again.
[0051]
By the control of the controller 9 described above, the fluctuation of the susceptor temperature Ts is suppressed as compared with the conventional case, and a good control result is obtained.
[0052]
As mentioned above, although embodiment of this invention was described, this is an illustration for description of this invention, and is not the meaning which limits the scope of the present invention only to this embodiment. Therefore, the present invention can be implemented in various other forms without departing from the gist thereof.
[0053]
For example, the part that feeds back the discharge temperature T1 is removed from the configuration shown in FIG. 2, and only the susceptor temperature Ts is fed back to the controller 9, and the controller 9 directly controls the susceptor temperature Ts to the target temperature. The principle of the present invention can also be applied to a configuration in which the temperature of the heat transfer fluid is controlled by performing calculations and controlling the power of the heat transfer device according to the calculation results.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a conventional control method based only on a discharge temperature T1.
FIG. 2 is a block diagram showing the overall configuration of an embodiment of the present invention.
FIG. 3 is a flowchart showing a flow of overall control operation performed by a controller 9;
4 is a flowchart showing a flow of follow-up control in FIG.
FIG. 5 is a block diagram showing a configuration for feedback temperature control used in this embodiment.
6 is a diagram showing an example of change curves of the discharge temperature T1 and the susceptor temperature Ts by the follow-up control of FIG.
7 is a flowchart showing the flow of additional value control in FIG. 3;
8 is a diagram showing an example of a change curve of a susceptor temperature Ts by additional value control of FIG.
FIG. 9 is a flowchart showing a flow of RF-ON region processing in FIG.
10 is a flowchart showing a flow of processing for outputting an initial output in FIG. 9;
FIG. 11 is a flowchart showing a flow of RF-OFF area processing in FIG. 7;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Chiller 2, 3 Piping which circulates heat transfer fluid 4 Process chamber 5 Susceptor 6 Cooler 7, 8 using thermoelectric conversion device Piping 9 which circulates cooling water Controller 10 Temperature sensor 11 which detects discharge temperature T1 Discharge temperature T1 Detection signal 12 Temperature sensor 13 for detecting susceptor temperature Ts Detection signal 14 for susceptor temperature Ts High frequency (RF) power supply device 15 Operation signal 203 for high frequency power supply device I-PD calculation unit 204 of controller 9 Cooler 205 Susceptor

Claims (4)

A cooling / heating device (6) for cooling or heating the heat transfer fluid supplied to the object (5);
A heat medium temperature sensor (10) for detecting a current temperature of the heat medium fluid;
And the object temperature sensor for detecting the current temperature of the object (5) and (12),
A feedback control operation using a current heat medium temperature (T1) from the heat medium temperature sensor and a current object temperature (Ts) from the object temperature sensor is performed, and the cooling / heating device (6) A controller (9) for outputting an operation amount with respect to
The controller (9) sets the object temperature (Ts) to a desired temperature (Ts) in the feedback control operation while a predetermined process in which a heat load is applied to the object (5) from the outside. SV) to determine the target temperature of the heat medium temperature (T1), to determine the manipulated variable to control the heat medium temperature (T1) to the determined target temperature ,
The controller (9) inputs the magnitude of the thermal load to be applied from the outside to the object (5) and the ON / OFF signal of the thermal load during the predetermined process before the predetermined process starts. Determining an initial value of the manipulated variable according to the input thermal load, and initially outputting the determined initial value when the predetermined process starts.
A device for adjusting the temperature of an object using a heat transfer fluid. The cooling / heating unit (6) The apparatus of claim 1, wherein the cooling or heating the heat medium fluid using a thermoelectric conversion device. The controller (9) stabilizes the object temperature (TS) at the desired temperature (SV) in a state where no external heat load is applied to the object (5) before the predetermined process starts. Holding a value related to the magnitude of the manipulated variable necessary to maintain and adjusting the initial value using the held value when determining the initial value,
The apparatus of claim 1 . Cooling or heating the heat transfer fluid supplied to the object (5);
Detecting a current temperature of the heat transfer fluid;
Detecting the current temperature of the object (5);
Performing a feedback control operation using the detected current heat medium temperature (T1) and the current object temperature (Ts) to control the amount of cooling or heating of the heat medium fluid,
The controlling step includes
While the predetermined process in which a heat load is applied to the object (5) from the outside is performed, the heat medium temperature (T1) is controlled so as to control the object temperature (Ts) to a desired temperature (SV). ) Determining a target temperature;
Adjusting the amount of cooling or heating to control the heat medium temperature (T1) to the determined target temperature while the predetermined process is performed ;
Before starting the predetermined process, inputting a thermal load magnitude and a thermal load ON / OFF signal to be externally applied to the object (5) during the feedback control operation;
Determining an initial value of the manipulated variable according to an input magnitude of the thermal load before the predetermined process starts;
Initially outputting the determined initial value when the predetermined process starts ,
A method for adjusting the temperature of an object using a heat transfer fluid.

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