Temperature control system

Abstract

This invention provides a temperature control system that can stabilize the supply temperature of the coolant used to control the temperature of the processing chamber in response to rapid temperature changes in the coolant, thereby reducing the capacity of the coolant tank. [Solution] The temperature control system 1 comprises a cooling device 3 for cooling the coolant, a coolant tank 15 connected to a coolant return line 11, a first temperature measuring device 61 located upstream of the coolant tank 15 for measuring the first temperature of the coolant flowing through the coolant return line 11, a second temperature measuring device 62 located downstream of the coolant tank 15 for measuring the second temperature of the coolant flowing through the coolant return line 11, and an operation control unit 60 that calculates an index temperature using the first and second temperatures and first and second weights multiplied by the first and second temperatures, respectively, and performs feedforward control to the cooling device 3 based on the index temperature.

Description

Technical Field

[0001] The present invention relates to a temperature control system for controlling the temperature of semiconductor manufacturing equipment such as etching equipment, CVD equipment, and PVD equipment.

Background Art

[0002] In order to control the temperature of semiconductor manufacturing equipment such as etching equipment, CVD equipment, and PVD equipment, a cooling device is used. This cooling device is configured to cool the coolant supplied from the coolant tank by a refrigerator and cool the semiconductor manufacturing equipment by flowing the coolant through the semiconductor manufacturing equipment.

[0003] The cooling device includes a coolant tank that stores the coolant, a supply system for the coolant that cools the coolant sent from the coolant tank by a refrigerator and supplies it to the semiconductor manufacturing equipment, a return system for the coolant that stores the coolant returned from the semiconductor manufacturing equipment in the coolant tank, and a control system that detects the temperature of the coolant supplied to the semiconductor manufacturing equipment by a liquid temperature sensor and performs feedback control on the refrigerator so that the detected temperature becomes a preset target temperature.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The demand for miniaturization of cooling systems necessitates minimizing the volume of the coolant tank. However, reducing the volume of the coolant tank reduces its buffering function. For example, if the temperature of the coolant returning from the semiconductor manufacturing equipment rises rapidly due to load fluctuations, the temperature of the coolant sent from the coolant tank to the refrigerator will also rise rapidly. As a result, a response delay occurs in the cooling control of the refrigerator (refrigeration cycle), and the temperature of the coolant to be supplied to the semiconductor manufacturing equipment cannot keep up with the target temperature. In other words, reducing the volume of the coolant tank makes it impossible to ensure highly accurate and stable temperature control, thus limiting the reduction in coolant tank volume and, furthermore, the miniaturization of the cooling system.

[0006] Therefore, the present invention provides a temperature control system that can stabilize the supply temperature of the coolant used for temperature control of a processing chamber in the event of a rapid temperature change, and can reduce the capacity of the coolant tank. [Means for solving the problem]

[0007] In one embodiment, a temperature control system for controlling the temperature of a processing chamber in a semiconductor manufacturing apparatus is provided, comprising: a cooling device for cooling a coolant; a coolant supply line for transporting the coolant cooled by the cooling device and used for temperature control of the processing chamber; a coolant return line for returning the coolant used for temperature control of the processing chamber back to the cooling device; a coolant tank connected in the middle of the coolant return line; a first temperature measuring instrument positioned upstream of the coolant tank for measuring a first temperature of the coolant flowing through the coolant return line; a second temperature measuring instrument positioned downstream of the coolant tank for measuring a second temperature of the coolant flowing through the coolant return line; and an operation control unit that calculates an index temperature using the first and second temperatures and first and second weights multiplied by the first and second temperatures, respectively, and performs feedforward control of the cooling device based on the index temperature.

[0008] Cooling systems do not respond immediately to operational control. The controlled parameters include the rotational speed of the cooling system's inverter and the opening degree of the hot gas bypass valve. For example, when controlling the rotational speed of the inverter, it takes time for the refrigerant in the evaporator to reach equilibrium after the compressor's rotational speed changes, resulting in a response delay. If we assume there is no response delay (response delay time) in the cooling system, then good control results can be obtained by directly controlling the cooling system at the second temperature just before it enters the evaporator. However, in reality, there is a response delay (response delay time) in the cooling system control, so the second temperature cannot be used directly for control. Here, we define the second temperature, which takes into account the response delay of the cooling system's control, as the index temperature. The index temperature can be said to be the second temperature obtained by considering the response delay time relative to the current second temperature. By using this indicator temperature, the cooling system can be controlled effectively. Specifically, the indicator temperature depends on the amount of coolant in the coolant tank and the coolant flow rate. Experiments have shown that the indicator temperature can be calculated by weighting the first and second temperatures. According to the experimental results, the calculated indicator temperature matched the experimentally measured value of the second temperature, which takes into account the response delay (response delay time) of the cooling system control, thus proving that the calculation of the indicator temperature is correct. By using this indicator temperature to perform feedforward control of the cooling system, optimal coolant temperature control can be achieved. In particular, the temperature control system can stabilize the coolant supply temperature in response to rapid temperature changes in the coolant used to control the temperature of the processing chamber.

[0009] In one embodiment, the operation control unit is configured to perform feedforward control on the cooling device to achieve the required refrigeration capacity based on the difference between the target temperature of the coolant flowing through the coolant supply line and the index temperature. The motion control unit controls the cooling capacity of the cooling device according to feedforward control, thereby bringing the temperature of the coolant flowing through the coolant supply line to the target temperature. As a result, the temperature control system can stabilize the supply temperature of the coolant.

[0010] In one embodiment, the temperature control system further comprises a third temperature measuring instrument arranged in the coolant supply line for measuring the third temperature of the coolant cooled by the cooling device, and the operation control unit is configured to calculate the required refrigeration capacity for the cooling device based on the difference between the third temperature and the index temperature, and to perform the feedforward control on the cooling device to achieve the calculated refrigeration capacity. The motion control unit controls the cooling capacity of the cooling device according to feedforward control, thereby bringing the temperature of the coolant flowing through the coolant supply line to the target temperature. As a result, the temperature control system can stabilize the supply temperature of the coolant.

[0011] In one embodiment, the temperature control system further comprises a flow meter for measuring the flow rate of the coolant flowing through the coolant return line, and the operation control unit is configured to determine a first weight and a second weight that change according to the flow rate of the coolant, wherein the first weight increases with increasing flow rate and decreases with decreasing flow rate, and the second weight decreases with increasing flow rate and increases with decreasing flow rate. The first and second temperature measuring devices are located upstream of the cooling device in the direction of coolant flow. Therefore, the indicator temperature can change depending on the flow rate of coolant flowing from the first and second temperature measuring devices to the cooling device. The operation control unit can calculate the accurate indicator temperature by changing the first and second weights according to the coolant flow rate.

[0012] In one embodiment, the temperature control system further comprises a liquid level measuring device for measuring the liquid level of the coolant in the coolant tank, and the operation control unit is configured to determine a first weight and a second weight that change according to the flow rate of the coolant and the liquid level, wherein the first weight increases in accordance with an increase in the flow rate and a decrease in the liquid level, and decreases in accordance with a decrease in the flow rate and a rise in the liquid level, and the second weight decreases in accordance with an increase in the flow rate and a decrease in the liquid level, and increases in accordance with a decrease in the flow rate and a rise in the liquid level. The indicator temperature can vary depending on the coolant flow rate as well as the coolant level in the coolant tank (i.e., the amount of coolant in the coolant tank). The control unit can calculate the accurate indicator temperature by changing the first and second weights according to the coolant flow rate and the coolant level in the coolant tank.

[0013] In one embodiment, the temperature control system further comprises a liquid level measuring instrument for measuring the liquid level of the coolant in the coolant tank, and the operation control unit is configured to determine a first weight and a second weight that change according to the liquid level of the coolant, wherein the first weight decreases as the liquid level rises and increases as the liquid level falls, and the second weight increases as the liquid level rises and decreases as the liquid level falls. The coolant tank is located upstream of the cooling system in the direction of coolant flow. Therefore, the indicator temperature can vary depending on the coolant level in the coolant tank (i.e., the amount of coolant in the coolant tank). The control unit can calculate the accurate indicator temperature by changing the first and second weights according to the coolant level.

[0014] In one embodiment, the temperature control system further includes a third temperature measuring instrument for measuring the third temperature of the coolant flowing through the coolant supply line, and the operation control unit is configured to perform feedback control on the cooling device to minimize the difference between the target temperature of the coolant flowing through the coolant supply line and the third temperature. The motion control unit can generate a coolant at a more stable temperature by performing both feedforward control and feedback control. For example, if the temperature change of the coolant is small, the motion control unit can maintain a stable coolant temperature according to feedback control, and if the temperature change of the coolant is large, it can maintain the coolant temperature according to feedforward control based on an index temperature. [Effects of the Invention]

[0015] The temperature control system can stabilize the supply temperature of the coolant used to control the temperature of the processing chamber, even in the face of rapid temperature changes. As a result, the coolant tank can be made smaller. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic diagram illustrating one embodiment of a temperature control system for controlling the temperature of a single processing chamber used in semiconductor manufacturing. [Figure 2] This is a schematic diagram showing one embodiment of a temperature control system for controlling the temperatures of multiple processing chambers used in semiconductor manufacturing. [Modes for carrying out the invention]

[0017] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a schematic diagram showing one embodiment of a temperature control system 1 for controlling the temperature of a processing chamber for semiconductor manufacturing. An example of a coolant is brine. Specific examples of brine include ethylene glycol, propylene glycol, aqueous calcium chloride solution, silicone oil, and fluorine-based inert liquids.

[0018] The processing chamber 100 is used for semiconductor manufacturing, and processing on the wafer is performed within the processing chamber 100. Examples of semiconductor manufacturing apparatuses include an etching apparatus, a CVD apparatus, a PVD apparatus, and the like. In the embodiment shown in FIG. 1, the temperature control system 1 is for controlling the temperature of one processing chamber 100, but may be used for controlling the temperatures of a plurality of processing chambers. The temperature control system 1 of the present embodiment is directly or indirectly connected to the processing chamber 100.

[0019] As shown in FIG. 1, the temperature control system 1 includes a cooling device 3 for cooling the coolant, a coolant pump 7 for transferring the coolant, a coolant feed line 10 for transferring the coolant cooled by the cooling device 3 and used for temperature control of the processing chamber 100, a coolant return line 11 for returning the coolant after being used for temperature control of the processing chamber 100 to the cooling device 3, and a coolant tank 15 for storing the coolant. The coolant tank 15 is connected to the coolant return line 11. The coolant return line 11 includes a coolant return line 11-1 and a coolant return line 11-2. The coolant return line 11-1 is disposed upstream of the coolant tank 15, and the coolant return line 11-2 is disposed downstream of the coolant tank 15. In the present embodiment, the coolant pump 7 is provided in the coolant feed line 10, but in other embodiments, it may be provided in the coolant line 11-2.

[0020] The coolant feed line 10 and the coolant return line 11 are directly or indirectly connected to the processing chamber 100. When the coolant feed line 10 and the coolant return line 11 are directly connected to the processing chamber 100, the coolant flows through the coolant feed line 10 into the processing chamber 100, and while passing through the processing chamber 100, the coolant directly cools the processing chamber 100. The coolant that has cooled the processing chamber 100 flows into the coolant return line 11.

[0021] When the coolant supply line 10 and the coolant return line 11 are indirectly connected to the processing chamber 100, the coolant indirectly cools the processing chamber 100 by cooling other coolants flowing through the processing chamber 100. Specifically, the coolant supply line 10 and the coolant return line 11 are connected to the processing chamber 100 via a heat exchanger or temperature control device (not shown). The heat exchanger or temperature control device performs heat exchange between the coolant supplied from the coolant supply line 10 and other coolants flowing through the processing chamber 100. The coolant that has undergone heat exchange in the heat exchanger or temperature control device flows into the coolant return line 11. With this configuration, the coolant used in the temperature control system 1 and the coolant flowing through the processing chamber 100 can be different coolants, thus reducing the amount of coolant in the processing chamber 100.

[0022] After being used to control the temperature of the processing chamber 100, the coolant is sent to the coolant tank 15 via the coolant return line 11-1 and temporarily stored in the coolant tank 15. When the coolant pump 7 is operated, the coolant is transferred from the coolant tank 15 to the cooling device 3 via the coolant return line 11-2. The temperature control system 1 is equipped with a liquid level measuring instrument 16 for measuring the liquid level of the coolant in the coolant tank 15.

[0023] In the embodiment shown in Figure 1, the cooling device 3 consists of a compression chiller (turbo chiller). More specifically, the cooling device 3 includes an evaporator 25 that generates refrigerant vapor by evaporating the refrigerant liquid using the heat of the coolant, a compressor 26 that compresses the refrigerant vapor, and a condenser 28 that generates refrigerant liquid by condensing the compressed refrigerant vapor with a cooling fluid (e.g., cooling water). The evaporator 25, compressor 26, and condenser 28 are connected by refrigerant piping 30. An expansion valve 31 is attached to the refrigerant piping 30 extending from the condenser 28 to the evaporator 25.

[0024] The cooling system 3 further includes a hot gas bypass line 33 that leads the refrigerant vapor compressed by the compressor 26 to the evaporator 25, bypassing the condenser 28, and a flow control valve 34 that adjusts the flow rate of the compressed refrigerant vapor flowing through the hot gas bypass line 33. The flow control valve 34 is mounted on the hot gas bypass line 33. The flow control valve 34 is an actuator-driven flow control valve and consists of, for example, an electrically operated valve or a solenoid valve with a variable opening. When the opening of the flow control valve 34 increases, the flow rate of refrigerant vapor flowing through the hot gas bypass line 33 increases, resulting in a decrease in the cooling capacity of the cooling system 3.

[0025] The compressor 26 comprises an impeller 45 for compressing refrigerant vapor and an electric motor 48 for rotating the impeller 45. The impeller 45 may be a single-stage impeller or a multi-stage impeller. The compressor 26 is equipped with an inverter 50 for changing the operating frequency of the electric motor 48. The inverter 50 is powered by a commercial power source. The inverter 50 is configured to supply variable-frequency power to the electric motor 48.

[0026] The cooling capacity of the cooling device 3 can be controlled by the rotational speed of the compressor 26 and the flow rate of refrigerant vapor flowing through the hot gas bypass line 33 (i.e., the opening degree of the flow control valve 34). Specifically, increasing the rotational speed of the compressor 26 increases the cooling capacity of the cooling device 3. On the other hand, increasing the flow rate of refrigerant vapor flowing through the hot gas bypass line 33 decreases the cooling capacity of the cooling device 3.

[0027] The temperature control system 1 further comprises an operation control unit 60 that controls the operation of the cooling device 3, i.e., the cooling capacity of the cooling device 3; a first temperature measuring instrument 61 located upstream of the coolant tank 15 and measuring the first temperature of the coolant flowing through the coolant return line 11-1; and a second temperature measuring instrument 62 located downstream of the coolant tank 15 and measuring the second temperature of the coolant flowing through the coolant return line 11-2. The first temperature measuring instrument 61 and the second temperature measuring instrument 62 are electrically connected to the operation control unit 60, and the measured values ​​of the first and second temperatures of the coolant are transmitted to the operation control unit 60. The operation control unit 60 is configured to perform feedforward control to the cooling device 3 based on the first and second temperatures of the coolant.

[0028] The temperature control system 1 further includes a third temperature measuring instrument 63 that measures the third temperature of the coolant cooled by the cooling device 3. The third temperature measuring instrument 63 is located in the coolant supply line 10 and is situated downstream of the cooling device 3. The third temperature measuring instrument 63 is electrically connected to the operation control unit 60, and the measured value of the third temperature of the coolant is transmitted to the operation control unit 60.

[0029] The operation control unit 60 is comprised of at least one computer. The operation control unit 60 includes a storage device 60a containing a program for controlling the operation of the cooling device 3, and an arithmetic unit 60b that performs calculations according to the instructions contained in the program. The storage device 60a includes main memory such as random access memory (RAM) and auxiliary storage such as a hard disk drive (HDD) or solid-state drive (SSD). Examples of the arithmetic unit 60b include a CPU (central processing unit) and a GPU (graphics processing unit). However, the specific configuration of the operation control unit 60 is not limited to these examples.

[0030] The cooling device 3 does not respond immediately even when its operation is controlled. The controlled objects include the rotational speed of the inverter 50 of the cooling device 3 and the opening degree of the flow control valve 34 attached to the hot gas bypass line 33. For example, when the rotational speed of the inverter 50 is controlled, it takes time for the refrigerant in the evaporator 25 to reach an equilibrium state after the rotational speed of the compressor 26 changes, which causes a response delay.

[0031] If we assume that there is no response delay (response delay time) in the cooling device 3, then good control results can be obtained by directly performing feedforward control to the cooling device 3 at the second temperature just before it enters the evaporator 25. However, in reality, there is a response delay (response delay time) in the control of the cooling device 3, so the second temperature cannot be used directly for feedforward control.

[0032] Therefore, in this embodiment, the operation control unit 60 is configured to calculate an index temperature using the first temperature and the second temperature, and the first weight and the second weight multiplied by the first temperature and the second temperature, respectively, and to perform feedforward control to the cooling device 3 based on the index temperature. The index temperature can be said to be the second temperature obtained by taking into account the response delay time of the cooling device 3, relative to the current second temperature.

[0033] In one embodiment, the operation control unit 60 calculates the required refrigeration capacity for the cooling device 3 by multiplying the difference between the target temperature of the coolant flowing through the coolant supply line 10 and the index temperature by the flow rate, specific heat, and density of the coolant, and is configured to perform feedforward control on the cooling device 3 to cancel out the time change in the calculated refrigeration capacity. As described above, the refrigeration capacity of the cooling device 3 can be controlled by the rotational speed of the compressor 26 and the flow rate of the refrigerant vapor flowing through the hot gas bypass line 33. Therefore, by controlling at least one of the rotational speed of the compressor 26 and the flow rate of the refrigerant vapor flowing through the hot gas bypass line 33 according to feedforward control, the operation control unit 60 can prevent the temperature of the coolant flowing through the coolant supply line 10 from deviating from the target temperature even when the temperature of the coolant returning to the coolant return line 11 changes due to a heat load from the processing chamber 100. As a result, the temperature control system 1 can stabilize the supply temperature of the coolant. In this embodiment, a turbo chiller was used as an example, but it is not limited to a turbo chiller; chillers using other compressors such as screw or scroll chillers may also be used.

[0034] In other embodiments, the operation control unit 60 is configured to perform feedforward control on the cooling device 3 to achieve the required refrigeration capacity based on the difference between the third temperature measured by the third temperature measuring instrument 63 and the index temperature. The operation control unit 60 controls at least one of the rotational speed of the compressor 26 and the flow rate of refrigerant vapor flowing through the hot gas bypass line 33 according to feedforward control, thereby bringing the temperature of the coolant flowing through the coolant supply line 10 to the target temperature. As a result, the temperature control system 1 can stabilize the supply temperature of the coolant.

[0035] The calculation of the indicator temperature is described in detail below. The temperature control system 1 further includes a flow meter 66 for measuring the flow rate of the coolant flowing through the coolant return line 11. In this embodiment, the flow meter 66 is attached to the coolant supply line 10. In other embodiments, the flow meter 66 may be attached to the coolant return line 11-2. The flow meter 66 is electrically connected to the operation control unit 60, and the measured value of the coolant flow rate is transmitted to the operation control unit 60. Here, the flow rate may also be a converted flow rate from pressure using a pressure-flow rate relationship formula, so the flow meter 66 may also be a pressure meter.

[0036] The operation control unit 60 is configured to determine a first weight and a second weight that change according to the flow rate of the coolant. The first weight increases as the flow rate of the coolant increases and decreases as the flow rate of the coolant decreases. The second weight decreases as the flow rate of the coolant increases and increases as the flow rate of the coolant decreases.

[0037] More specifically, the operation control unit 60 stores the following calculation formula for calculating the indicator temperature in the storage device 60a. Index temperature = 2nd temperature * 2nd weight + 1st temperature * 1st weight =2nd temperature*(a-flow rate*b)+1st temperature*(1-(a-flow rate*b)) a and b are constants determined from the distance traveled by the coolant from the first temperature measuring instrument 61 and the second temperature measuring instrument 62 to the cooling device 3, the rated flow rate of the coolant, the capacity (size) of the coolant tank 15, and so on.

[0038] The first weight is determined from 1 - (a - flow rate * b), and the second weight is determined from a - flow rate * b. In one embodiment, the first and second weights are numerical values ​​in the range of 0 to 1. The constants a and b are predetermined from the specifications of the temperature control system 1, experimental results using the temperature control system 1, etc.

[0039] The first temperature measuring device 61 and the second temperature measuring device 62 are located upstream of the cooling device 3 in the direction of coolant flow. Therefore, the indicator temperature can change depending on the flow rate of coolant flowing from the first temperature measuring device 61 and the second temperature measuring device 62 to the cooling device 3. The operation control unit 60 can calculate an accurate indicator temperature by changing the first and second weights according to the flow rate of the coolant. By performing feedforward control of the cooling device 3 using this indicator temperature, optimal coolant temperature control can be achieved. In particular, the temperature control system 1 can stabilize the coolant supply temperature in response to rapid temperature changes of the coolant used for temperature control of the processing chamber 100.

[0040] In the embodiment described next, the operation control unit 60 is configured to determine a first weight and a second weight that change according to the coolant level in the coolant tank 15 (i.e., the amount of coolant in the coolant tank 15) instead of the coolant flow rate. The first weight decreases as the coolant level rises and increases as the coolant level falls. The second weight increases as the coolant level rises and decreases as the coolant level falls.

[0041] More specifically, the operation control unit 60 stores the following calculation formula for calculating the indicator temperature in the storage device 60a. Index temperature = 2nd temperature * 2nd weight + 1st temperature * 1st weight = Second temperature * (liquid level * c + d) + First temperature * (1 - (liquid level * c + d)) c and d are constants determined from the distance traveled by the coolant from the first temperature measuring instrument 61 and the second temperature measuring instrument 62 to the cooling device 3, the rated flow rate of the coolant, the capacity (size) of the coolant tank 15, and so on.

[0042] The first weight is determined from 1 - (liquid level * c + d), and the second weight is determined from the liquid level * c + d. In one embodiment, the first and second weights are numerical values ​​in the range of 0 to 1. The constants c and d are predetermined from the specifications of the temperature control system 1, experimental results using the temperature control system 1, etc.

[0043] The coolant tank 15 is located upstream of the cooling device 3 in the direction of coolant flow. Therefore, the indicator temperature can vary depending on the coolant level in the coolant tank 15 (i.e., the amount of coolant in the coolant tank 15). The operation control unit 60 can calculate the accurate indicator temperature by changing the first and second weights according to the coolant level.

[0044] In the embodiment described next, the operation control unit 60 is configured to determine a first weight and a second weight that change according to both the flow rate of the coolant and the liquid level of the coolant in the coolant tank 15. The first weight increases in accordance with an increase in the flow rate of the coolant and a decrease in the liquid level of the coolant, and decreases in accordance with a decrease in the flow rate of the coolant and a rise in the liquid level of the coolant. The second weight decreases in accordance with an increase in the flow rate of the coolant and a decrease in the liquid level of the coolant, and increases in accordance with a decrease in the flow rate of the coolant and a rise in the liquid level of the coolant.

[0045] More specifically, the operation control unit 60 stores the following calculation formula for calculating the indicator temperature in the storage device 60a. Index temperature = 2nd temperature * 2nd weight + 1st temperature * 1st weight = Second temperature * (Liquid level * c + d + (a - flow rate * b)) + First temperature * (1 - (Liquid level * c + d + (a - flow rate * b))) a, b, c, and d are constants determined from the distance traveled by the coolant from the first temperature measuring instrument 61 and the second temperature measuring instrument 62 to the cooling device 3, the rated flow rate of the coolant, the capacity (size) of the coolant tank 15, and so on.

[0046] The first weight is determined from 1 - (liquid level * c + d + (a - flow rate * b)), and the second weight is determined from liquid level * c + d + (a - flow rate * b). In one embodiment, the first and second weights are numerical values ​​in the range of 0 to 1. The constants a, b, c, and d are predetermined from the specifications of the temperature control system 1, experimental results using the temperature control system 1, etc.

[0047] The indicator temperature can vary depending on the coolant flow rate as well as the coolant level in the coolant tank 15 (i.e., the amount of coolant in the coolant tank 15). The operation control unit 60 can calculate the accurate indicator temperature by changing the first and second weights according to the coolant flow rate and the coolant level in the coolant tank 15.

[0048] As shown in Figure 1, the temperature control system 1 includes a third temperature measuring instrument 63 that measures the third temperature of the coolant flowing through the coolant supply line 10. In one embodiment, the operation control unit 60 is configured to perform feedback control on the cooling device 3 to minimize the difference between the target temperature of the coolant flowing through the coolant supply line 10 and the third temperature measured by the third temperature measuring instrument 63.

[0049] The operation control unit 60 can generate coolant at a more stable temperature by performing both feedforward control based on the index temperature and feedback control based on the third temperature of the coolant. For example, if the temperature change of the coolant is small, the operation control unit 60 can perform stable coolant temperature control according to the feedback control, and if the temperature change of the coolant is large, it can perform coolant temperature control according to feedforward control based on the index temperature. Furthermore, as the stability of temperature control improves, it becomes possible to satisfy temperature control requirements with a smaller tank capacity, and the capacity of the coolant tank 15 can be reduced.

[0050] In the embodiment shown in Figure 1, the temperature control system 1 controls the temperature of one processing chamber 100, but the temperature control system 1 can also control the temperatures of multiple processing chambers 100.

[0051] Figure 2 is a schematic diagram showing one embodiment of a temperature control system 1 for controlling the temperatures of multiple processing chambers 100 for semiconductor manufacturing. The configuration and operation of the present invention, which are not specifically described, are the same as those described in the embodiment with reference to Figure 1, so redundant explanations are omitted.

[0052] The multiple processing chambers 100 are used in semiconductor manufacturing, and processing of wafers is performed within each processing chamber 100. In one example, a single semiconductor manufacturing apparatus may have these multiple processing chambers 100, while in another example, multiple semiconductor manufacturing apparatuses may each have multiple processing chambers 100.

[0053] The temperature control system 1 of this embodiment is directly or indirectly connected to a plurality of processing chambers 100. In the embodiment shown in Figure 2, three processing chambers 100 are connected to the temperature control system 1, but the number of processing chambers 100 is not limited to the embodiment shown in Figure 2. Four or more processing chambers 100 may be connected to the temperature control system 1.

[0054] The coolant supply line 10 includes multiple branch supply lines 10a corresponding to multiple processing chambers 100, and the coolant return line 11-1 includes multiple merging return lines 11a corresponding to multiple processing chambers 100.

[0055] Multiple branching feed lines 10a and multiple merging return lines 11a are directly or indirectly connected to multiple processing chambers 100. When the multiple branching feed lines 10a and multiple merging return lines 11a are directly connected to the multiple processing chambers 100, the coolant flows through the multiple branching feed lines 10a to the multiple processing chambers 100, and as it passes through the multiple processing chambers 100, the coolant directly cools these processing chambers 100. The coolant that has cooled the multiple processing chambers 100 flows into the multiple merging return lines 11a.

[0056] When multiple branching feed lines 10a and multiple merging return lines 11a are indirectly connected to multiple processing chambers 100, the coolant indirectly cools the multiple processing chambers 100 by cooling the other coolants flowing through the multiple processing chambers 100. Specifically, the multiple branching feed lines 10a and multiple merging return lines 11a are connected to the multiple processing chambers 100 via multiple heat exchangers or temperature control devices (not shown). The multiple heat exchangers or temperature control devices perform heat exchange between the coolant supplied from the multiple branching feed lines 10a and the other coolants flowing through the multiple processing chambers 100. The coolant that has undergone heat exchange in the multiple heat exchangers or temperature control devices flows into the multiple merging return lines 11a.

[0057] In the embodiment shown in Figure 2, as in the embodiment described with reference to Figure 1, the operation control unit 60 is configured to calculate an index temperature using the first temperature and the second temperature, and the first weight and the second weight multiplied by the first temperature and the second temperature, respectively, and to perform feedforward control to the cooling device 3 based on the index temperature.

[0058] The embodiments described above are intended to enable persons with ordinary skill in the art to implement the present invention. Various modifications of the above embodiments can be made naturally by those skilled in the art, and the technical idea of ​​the present invention can be applied to other embodiments as well. Therefore, the present invention is not limited to the embodiments described, but is to be interpreted in the broadest sense according to the technical idea defined by the claims. [Explanation of Symbols]

[0059] 1. Temperature control system 3 Cooling device 7 Coolant pump 10 Coolant supply line 10a Branch feed line 11,11-1,11-2 Coolant return line 11a Merging return line 15 Coolant tank 16. Liquid level measuring instrument 25 Evaporator 26 Compressor 28 Condenser 30 Refrigerant piping 31 Expansion valve 33 Hot gas bypass line 34 Flow control valve 45 Impeller 48 Electric motor 50 Inverters 60 Operation Control Unit 60a Storage Device 60b Arithmetic unit 61 1st temperature measuring device 62 Second temperature measuring device 63 Third temperature measuring device 66 Flow meter 100 Processing Chambers

Claims

1. A temperature control system for controlling the temperature of a processing chamber in a semiconductor manufacturing apparatus, A cooling device for cooling the coolant, A coolant supply line for transferring the coolant, which is cooled by the cooling device and used for temperature control of the processing chamber, A coolant return line that returns the coolant used for temperature control of the processing chamber to the cooling device, A coolant tank connected in the middle of the coolant return line, A first temperature measuring device is positioned upstream of the coolant tank and measures the first temperature of the coolant flowing through the coolant return line, A second temperature measuring device is positioned downstream of the coolant tank and measures the second temperature of the coolant flowing through the coolant return line. A temperature control system comprising an operation control unit that calculates an index temperature using the first temperature and the second temperature, and a first weight and a second weight multiplied by the first temperature and the second temperature, respectively, and performs feedforward control of the cooling device based on the index temperature.

2. The temperature control system according to claim 1, wherein the operation control unit is configured to perform the feedforward control on the cooling device to achieve the required refrigeration capacity for the cooling device based on the difference between the target temperature and the index temperature of the coolant flowing through the coolant supply line.

3. The temperature control system further comprises a third temperature measuring instrument positioned in the coolant supply line and measuring the third temperature of the coolant cooled by the cooling device, The temperature control system according to claim 1, wherein the operation control unit is configured to calculate the required refrigeration capacity for the cooling device based on the difference between the third temperature and the index temperature, and to perform the feedforward control on the cooling device to achieve the calculated refrigeration capacity.

4. The temperature control system further includes a flow meter for measuring the flow rate of the coolant flowing through the coolant return line, The operation control unit is configured to determine the first weight and the second weight, which change according to the flow rate of the coolant. The first weight increases with increasing flow rate and decreases with decreasing flow rate. The temperature control system according to claim 1, wherein the second weight decreases with increasing flow rate and increases with decreasing flow rate.

5. The temperature control system further includes a liquid level measuring device for measuring the liquid level of the coolant in the coolant tank, The operation control unit is configured to determine the first weight and the second weight, which change according to the flow rate of the coolant and the liquid level. The first weight increases in accordance with the increase in flow rate and the decrease in liquid level, and decreases in accordance with the decrease in flow rate and the rise in liquid level. The temperature control system according to claim 4, wherein the second weight decreases in accordance with an increase in the flow rate and a decrease in the liquid level, and increases in accordance with a decrease in the flow rate and a rise in the liquid level.

6. The temperature control system further includes a liquid level measuring device for measuring the liquid level of the coolant in the coolant tank, The operation control unit is configured to determine the first weight and the second weight, which change according to the liquid level of the coolant. The first weight decreases as the liquid level rises and increases as the liquid level falls. The temperature control system according to claim 1, wherein the second weight increases as the liquid level rises and decreases as the liquid level falls.

7. The temperature control system further includes a third temperature measuring instrument for measuring the third temperature of the coolant flowing through the coolant supply line, The temperature control system according to claim 1, wherein the operation control unit is configured to perform feedback control on the cooling device to minimize the difference between the target temperature of the coolant flowing through the coolant supply line and the third temperature.

8. The temperature control system according to claim 1, wherein the processing chamber is a plurality of processing chambers.

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