Cooling apparatus, semiconductor manufacturing apparatus, and semiconductor manufacturing method

Abstract

Provided is a cooling device for cooling an object to be cooled, characterized in that the cooling device comprises a circulation system configured to circulate a refrigerant for cooling the object to be cooled, in which a container is provided in the circulation system, the container includes a region in which heat exchange is performed between a refrigerant and at least a part of the object to be cooled, the refrigerant being a mixed refrigerant obtained by mixing a first refrigerant having a first boiling point and a second refrigerant having a second boiling point higher than the first boiling point, and the circulation system circulating the mixed refrigerant, the mixed refrigerant enters the container at a predetermined temperature, and the vapor pressure of the first refrigerant at the predetermined temperature is higher than the withstand pressure of the container.

Description

Technical Field

[0001] The present invention relates to a cooling device, a semiconductor manufacturing device and a semiconductor manufacturing method. Background Art

[0002] A semiconductor manufacturing device such as a pattern forming device (e.g., an exposure device, an imprint device, or an electron beam lithography device) or a plasma processing device (e.g., a CVD device, an etching device, or a sputtering device) includes a driving mechanism or a heat generating portion (e.g., a member heated by plasma). In order to cool the heat generating portion, the semiconductor manufacturing device includes a cooling device. The cooling device cools the heat generating portion by taking heat from the heat generating portion and discharging the heat to the outside of the device.

[0003] Patent document 1 (PTL 1) discloses a cooling system including an evaporator, a condenser, a pump, an accumulator, a heat exchanger, and a temperature sensor for extracting heat from a component. In the cooling system, a circulation path is configured to return a fluid refrigerant from the pump via the evaporator and the condenser to the pump, and the accumulator is in fluid communication with the circulation path. The heat exchanger transfers heat from and to the fluid refrigerant in the accumulator. At this time, the amount of heat transfer is controlled based on the output from the temperature sensor.

[0004] Reference List

[0005] Patent Literature

[0006] PTL 1: Japanese Patent No. 5313384 Summary of the invention

[0007] Technical issues

[0008] Generally, a cooling system that circulates a liquid refrigerant by a pump often uses a refrigerant that does not require a liquefaction device and has an atmospheric pressure boiling point equal to or higher than room temperature (for example, HFO-1336mzz(E), Novec7000, or HFO-1233zd(Z)). When a refrigerant is used and it is desired to set the boiling point temperature to be lower than the atmospheric pressure boiling point, the vapor pressure will be lower than the atmospheric pressure.

[0009] As a cooling object of the cooling system, a linear motor with a jacket structure is considered, in which a coil is arranged in a closed container and the coil is cooled by filling the internal space with a fluid refrigerant, and the boiling vaporized refrigerant flows through the upper part of the internal space of the jacket due to the density difference. When the heat generated by the coil is large, the amount of vaporized refrigerant increases, and the pressure is low. Therefore, the vaporized refrigerant occupies the internal space of the jacket, resulting in a state in which the upper part of the coil, which is the heat generating part, is covered by the vaporized refrigerant and cannot be boiled and cooled, that is, dried out. If dryout occurs, the temperature of the coil will rise sharply and the coil will be burned.

[0010] In order to cope with this problem, it is considered to supply a sufficient amount (flow rate) of refrigerant to boil and cool the coils that generate heat in the internal space of the jacket, but if the internal pressure is low, the vaporized refrigerant will expand to occupy the upper part of the internal space of the jacket, and thus it is impossible to prevent evaporation. It is to be noted that evaporation can be prevented by further increasing the flow rate of the refrigerant and flushing away the vaporized refrigerant. However, in this case, since this is equivalent to convection cooling, the advantage of boiling cooling that can recover a large amount of heat at a low flow rate cannot be obtained, resulting in a pressure resistance problem caused by the increase in the flow rate of the refrigerant, an increase in the size of the device, and an increase in energy consumption.

[0011] The invention provides a cooling device which is beneficial to cooling a cooling object.

[0012] Solution to the problem

[0013] A cooling device as one aspect of the present invention is a cooling device for cooling a cooling object, characterized in that it includes a circulation system, which is configured to circulate a refrigerant used to cool the cooling object, wherein a container is provided in the circulation system, the container includes an area for heat exchange between the refrigerant and at least a portion of the cooling object, the refrigerant is a mixed refrigerant obtained by mixing a first refrigerant with a first boiling point with a second refrigerant with a second boiling point higher than the first boiling point, and the circulation system circulates the mixed refrigerant so that the mixed refrigerant enters the container at a predetermined temperature, and the vapor pressure of the first refrigerant at the predetermined temperature is higher than the withstand pressure of the container.

[0014] Further aspects of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

[0015] Advantageous Effects of the Invention

[0016] According to the present invention, for example, a cooling device is provided that facilitates cooling a cooling object.

[0017] Other features and advantages of the present invention will become apparent from the following description in conjunction with the accompanying drawings.It should be noted that the same reference numerals in the various drawings represent the same or similar components. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.

[0019] Figure 1 is a schematic circuit diagram showing the arrangement of a cooling device according to a first embodiment of the present invention;

[0020] Figure 2 is a diagram showing an example of a saturated vapor pressure curve of a refrigerant;

[0021] Figure 3 is a diagram showing a saturated vapor pressure curve of a low boiling point refrigerant and a saturated vapor pressure curve of a mixed refrigerant;

[0022] Figure 4 is a schematic circuit diagram showing the arrangement of a cooling device according to a second embodiment of the present invention;

[0023] Figure 5 is a schematic circuit diagram showing the arrangement of a cooling device according to a third embodiment of the present invention;

[0024] Fig. 6A is a schematic circuit diagram showing the arrangement of a cooling device according to a fourth embodiment of the present invention;

[0025] Figure 6B is a schematic circuit diagram showing the arrangement of a cooling device according to a fourth embodiment of the present invention;

[0026] Figure 6C is a schematic circuit diagram showing the arrangement of a cooling device according to a fourth embodiment of the present invention;

[0027] Figure 7 is a schematic diagram showing the arrangement of an exposure device;

[0028] Figure 8 is a schematic diagram showing the arrangement of an imprinting apparatus; and

[0029] Fig. 9 is a schematic diagram showing the arrangement of a plasma processing apparatus. DETAILED DESCRIPTION

[0030] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments are not intended to limit the scope of the claimed invention. A plurality of features are described in the embodiments, but the invention is not intended to be limited to requiring all of these features, and a plurality of such features may be appropriately combined. In addition, in the accompanying drawings, the same reference numerals are assigned to the same or similar configurations, and their redundant descriptions are omitted.

[0031] <First Embodiment>

[0032] Figure 1: is a schematic circuit diagram showing the arrangement of the cooling device CA1 according to the first embodiment of the present invention. The cooling object of the cooling device CA1 is not limited to a specific object, for example, it is a semiconductor manufacturing device, in particular, a heat generating portion of the semiconductor manufacturing device. The semiconductor manufacturing device includes, for example, a pattern forming device such as an exposure device, an imprinting device, or an electron beam lithography device, or a plasma processing device such as a CVD device, an etching device, or a sputtering device. The pattern forming device includes a driving mechanism that drives a component such as a substrate and / or a master plate at high speed, and the driving mechanism generates heat as the component is driven, and thereby becomes a heat generating portion. In a plasma processing device, a component such as an electrode is heated by plasma, and the component becomes a heat generating portion.

[0033] The cooling device CA1 is configured to cool a cooling object 80 such as a heat generating portion. Figure 1 As shown, the cooling device CA1 includes a refrigerant cycle system 1, in which a condenser 2, a pump 3, a heater 4, a temperature sensor 5, a throttle valve 6, and a heat exchange container 7 are provided. The refrigerant cycle system 1 (cooling device CA1) forms a closed cycle system in which a cooling object 80 as a heat generating portion is stored in the heat exchange container 7 (inside). In the present embodiment, the entire cooling object 80 is stored in the heat exchange container 7, but the present invention is not limited thereto, and at least a portion of the cooling object 80 may be stored in the heat exchange container 7. The refrigerant 10 circulating through the refrigerant cycle system 1 is a mixed refrigerant obtained by mixing a low-boiling-point refrigerant 11 (a first refrigerant of a first boiling point) and a high-boiling-point refrigerant 12 (a second refrigerant of a second boiling point higher than the first boiling point), and more specifically, a "non-azeotropic mixed refrigerant".

[0034] The refrigerant 10 in a liquid phase state stored in (inside) the condenser 2 (hereinafter referred to as "liquid refrigerant 14") is sent to the heater 4 by the pump 3. In this way, the pump 3 has a function of sending the liquid refrigerant 14 (mixed refrigerant) from the condenser 2. The heater 4 heats the liquid refrigerant 14 sent from the pump 3 so that the refrigerant temperature detected by the temperature sensor 5 arranged on the downstream side of the heater 4 reaches a predetermined management temperature. The heater 4 includes, for example, an electric heater or a heat exchanger for heating the liquid refrigerant 14 (controlling the temperature of the liquid refrigerant 14), but the present invention is not limited thereto.

[0035] The pressure of the liquid refrigerant 14 that has been controlled to the management temperature is reduced by the throttle valve 6 to the extent that the low-boiling-point refrigerant 11 has a saturated vapor pressure at the management temperature, and the liquid refrigerant 14 is sent to the heat exchange container 7. In this way, the throttle valve 6 serves as a pressure reducer to reduce the pressure of the liquid refrigerant 14 sent from the pump 3 and supply the liquid refrigerant 14 to the heat exchange container 7.

[0036] The heat exchange container 7 includes a heat exchange area 72 that performs heat exchange with a cooling object 80, and the cooling object 80 is built in the heat exchange area 72. When the cooling object 80 built in the heat exchange container 7 generates heat, the low boiling point refrigerant 11 in the liquid refrigerant 14 (mixed refrigerant) supplied to the heat exchange container 7 boils to cool the cooling object 80 by latent heat of evaporation, and the high boiling point refrigerant 12 performs convection cooling on the cooling object 80. In this way, the low boiling point refrigerant 11 performs boiling cooling on the cooling object 80 in the heat exchange area 72 to enter a gas phase state in the heat exchange container, and the high boiling point refrigerant 12 performs convection cooling on the cooling object 80 in a liquid phase state in the heat exchange area 72 in the heat exchange container. The low boiling point refrigerant 11 that passes through the heat exchange area 72 in the heat exchange container and is discharged from the heat exchange container 7 returns to the condenser 2 in a liquid phase state or a gas-liquid mixed phase (two-phase) state according to the heat state of the cooling object 80. On the other hand, the high boiling point refrigerant 12 that has passed through the heat exchange region 72 in the heat exchange container and has been discharged from the heat exchange container 7 always returns to the condenser 2 in a liquid phase regardless of the heat generation state of the cooling object 80 .

[0037] In this embodiment, the condenser 2 condenses the refrigerant 10 (mixed refrigerant) in a gas-liquid mixed phase state discharged from the heat exchange container 7 to obtain a liquid refrigerant 14. In the condenser 2, a heat exchanger 8 and a pressure sensor 9 are provided. The condenser 2 performs heat generation control to the outside of the refrigerant cycle system 1 via the heat exchanger 8 so that the pressure detected by the pressure sensor 9 always becomes a predetermined pressure.

[0038] The boiling point in the heat exchange container 7 is determined by performing control so that the pressure of the low boiling point refrigerant 11 in the heat exchange container 7 reaches the saturated vapor pressure at the management temperature. In the case of boiling cooling, since heat is recovered by latent heat of evaporation, a larger heat recovery can be achieved at a certain temperature by a lower refrigerant flow rate.

[0039] When the low-boiling-point refrigerant 11 boils and evaporates, it becomes a refrigerant in a gas phase state (hereinafter referred to as "gas refrigerant 13"), floats due to the density difference with the high-boiling-point refrigerant 12, and occupies the upper space of the heat exchange container 7. However, in the present embodiment, a predetermined amount of high-boiling-point refrigerant 12 (liquid refrigerant 14) is always present in the heat exchange container, and the high-boiling-point refrigerant 12 is kept in a liquid phase state when passing through the cooling object 80. In other words, in the present embodiment, the high-boiling-point refrigerant 12 in a liquid phase state exists from the upstream side to the downstream side of the cooling object 80. Therefore, the exposure time of the cooling object 80 to the gas refrigerant 13 is reduced, thereby suppressing the occurrence of a state in which the cooling object 80 (the upper part thereof) is covered with the gas refrigerant 13 and boiling cooling cannot be performed, that is, the occurrence of evaporation can be suppressed.

[0040] In addition, when the cooling object 80 is a coil (coil wire) of a linear motor, the groove portion between the wires exists on the surface of the coil, so the high boiling point refrigerant 12 in the liquid phase enters the groove portion on the coil surface due to the capillary phenomenon, and the low boiling point refrigerant 11 in the liquid phase is also guided to the groove portion on the coil surface. This promotes boiling cooling of the cooling object 80, thereby suppressing the occurrence of evaporation.

[0041] It should be noted that if a refrigerant with a large calorific value for the cooling object 80 and a low vapor pressure at the management temperature is used as the low-boiling-point refrigerant 11, the upper part of the cooling object 80 will be exposed to the gas refrigerant 13, and the occurrence of evaporation cannot be suppressed only by the cooling effect of the high-boiling-point refrigerant 12.

[0042] In order to suppress the occurrence of evaporation, a refrigerant having a high vapor pressure at the management temperature is used as the low-boiling point refrigerant 11, and the occupied volume of the gas refrigerant 13 is reduced by pressure-compressing the gas refrigerant 13 that has lost its cooling capacity, thereby making it easy to expose the cooling object 80 to the liquid refrigerant 14.

[0043] It should be noted that in the case where the cooling object 80 is a linear motor with a jacket structure, it is necessary to move the coil inside the jacket and the magnet outside the jacket closer to each other to shorten the distance between the coil and the magnet in order to increase the thrust. Since the jacket has a thin-walled structure that transmits magnetic force, the pressure resistance is on the order of 100 kPa. Because the vapor pressure of a refrigerant such as R32 suitable for a general refrigeration cycle is on the order of MPa, such a refrigerant cannot be used in the case where the cooling object 80 is a linear motor with a jacket structure. It is desirable to increase the vapor pressure of the refrigerant as much as possible within the pressure resistance range, but it is difficult to select such a refrigerant.

[0044] To address this problem, in this embodiment, a non-azeotropic mixed refrigerant obtained by mixing a low boiling point refrigerant 11 and a high boiling point refrigerant 12 is used as a refrigerant for cooling the cooling object 80, and a physical phenomenon of increasing the boiling point of the low boiling point refrigerant 11 is utilized.

[0045] Figure 2 is a diagram showing an example of a saturated vapor pressure curve of a refrigerant. Figure 2 In the figure, the abscissa represents temperature T [K] and the ordinate represents vapor pressure P [Pa]. The saturated vapor pressure curve of the refrigerant is determined by the physical property values ​​of the refrigerant, is given by the following Clausius-Clapeyron formula, and is as follows Figure 2 The rising curve is shown.

[0046] dP / dT=L / (Vv-Vl) / Ts

[0047] Wherein, dP represents pressure change, dT represents temperature change, L represents latent heat, Vv represents vapor specific volume, Vl represents liquid specific volume, and Ts represents saturation temperature.

[0048] When the high boiling point refrigerant 12 is mixed with the low boiling point refrigerant 11, if the high boiling point refrigerant 12 is only a non-volatile refrigerant, the boiling point rise (ΔT) can be given by the following formula:

[0049] ΔT≈xs·R(T*) 2 / Lm

[0050] Where ΔT represents the boiling point rise, R represents the gas constant, T* represents the boiling point of the low-boiling pure refrigerant, xs represents the mole fraction of the high-boiling refrigerant, and Lm represents the molar latent heat of evaporation of the low-boiling refrigerant.

[0051] Reference Figure 2 , the boiling point rise of the low boiling point refrigerant 11 is equivalent to the saturated vapor pressure curve shifting to the high temperature side (to the right), and the vapor pressure of the low boiling point refrigerant 11 decreases at the management temperature. Therefore, the vapor pressure can be adjusted by adjusting the mixing ratio between the low boiling point refrigerant 11 and the high boiling point refrigerant 12.

[0052] For example, consider a case where the management temperature is 23 degrees and the withstand pressure of the heat exchange container 7 is 400 kPa abs. In addition, R-1234zeE (vapor pressure at 23 degrees: 450 kPa) whose vapor pressure at the management temperature is slightly higher than the withstand pressure of the heat exchange container 7 is used as the low boiling point refrigerant 11. Note that R-1234yf may also be used as the low boiling point refrigerant 11.

[0053] Figure 3 1 is a graph showing the saturated vapor pressure curve of R-1234zeE as the low boiling point refrigerant 11 and the saturated vapor pressure curve of a mixed refrigerant having a vapor pressure equal to the withstand pressure (400 kPa) at the management temperature. Figure 3 In the figure, the abscissa represents temperature [°C] and the ordinate represents vapor pressure [kPa]. Figure 3 , it is necessary to raise the boiling point by about 4 degrees. It should be understood that in order to raise the boiling point by 4 degrees, it is only necessary to mix the high boiling point refrigerant 12 by substituting the physical property values ​​of R-1234zeE into the above-mentioned boiling point rise (ΔT) formula so that the molar fraction is about 0.2. At this time, it is preferred that the high boiling point refrigerant 12 has affinity with the low boiling point refrigerant 11 and the saturated vapor pressure at the management temperature is sufficiently low.

[0054] If the vapor pressure of the low boiling point refrigerant 11 increases, the diameter of the bubbles of the gas refrigerant 13 generated by boiling cooling can be reduced. When Pv represents the internal pressure of the bubble, Pl represents the liquid pressure, r represents the bubble diameter, and σ represents the surface tension, the following formula holds because the force of the bubble is balanced.

[0055] Pv=Pl+2σ / r

[0056] According to this formula, the pressure inside the bubble is higher than the pressure of the surrounding liquid by ΔP=2σ / r.

[0057] In the interface of the bubble, the liquid is in a superheated state with a temperature higher than the saturation temperature. When Tl represents the superheated liquid temperature, Ps represents the saturated vapor pressure at the superheated liquid temperature, and Ts represents the saturated temperature at the liquid pressure Pl, the Clausius-Clapeyron formula is applied between the bubble and the liquid to obtain:

[0058] (Pv-Pl) / (Tl-Ts)=L / (Vv-Vl) / Ts

[0059] By approximating the formula by setting Vv>>Vl and Pv≈Ps, we obtain:

[0060] ΔP=Pv-Pl≈L(Tl-Ts) / Vv / Ts

[0061] When Vv is inversely proportional to Pl according to Boyle's law to allow for the physical properties of R-1234ZeE and several degrees of superheat, a pressure difference of about 100 kPa can be induced, and the bubbles can be compressed to about 1 / 5 relative to atmospheric pressure as the vapor pressure increases.

[0062] If a refrigerant having a large latent heat of evaporation is used as the low-boiling point refrigerant 11, the vapor volume is reduced and the amount of the gas refrigerant 13 can be reduced. The latent heat of R-1234ZeE is 195.4 J / g. Since R-1234ZeE is a refrigerant having a relatively large latent heat, it is a refrigerant suitable for dealing with evaporation, and has a global warming coefficient (GWP) of 6, so it performs well in terms of environmental protection.

[0063] As described above, in the present embodiment, in the refrigeration cycle system 1, the mixed refrigerant circulates so that the entire heat exchange area 72 of the heat exchange container 7 is exposed to the mixed refrigerant including the low-boiling point refrigerant 11 and the high-boiling point refrigerant 12, both of which are in a liquid phase state, and the mixed refrigerant in a gas-liquid mixed phase is discharged from the heat exchange container 7. To achieve this, the mixed refrigerant is mixed in such a mixing ratio that, in the heat exchange container, the low-boiling point refrigerant 11 boils and cools the cooling object 80 to enter a gas phase state, and the high-boiling point refrigerant 12 convectively cools the cooling object 80 in a liquid phase state and compresses the low-boiling point refrigerant 11 in a gas phase state.

[0064] More specifically, a non-azeotropic mixed refrigerant is used as the mixed refrigerant, and the mixing ratio between the low-boiling-point refrigerant 11 and the high-boiling-point refrigerant 12 is adjusted, thereby increasing the vapor pressure of the low-boiling-point refrigerant 11 to a high pressure close to the withstand pressure of the heat exchange container 7. In this way, the low-boiling-point refrigerant in the gas phase that has been generated by boiling cooling can be compressed. In addition, the bubble diameter of the low-boiling-point refrigerant in the gas phase is reduced, and the bubble internal pressure is increased by the curvature ratio of the bubble compared to the surrounding liquid. In this way, the low-boiling-point refrigerant in the gas phase that has been generated by boiling cooling can be further compressed. This compression effect reduces the occupied volume ratio of the low-boiling-point refrigerant in the liquid phase that has lost its cooling capacity in the heat exchange container, thereby suppressing the occurrence of evaporation.

[0065] <Second Embodiment>

[0066] Figure 4 : is a schematic circuit diagram showing the arrangement of a cooling device CA2 according to a second embodiment of the present invention. The cooling device CA2 according to the present embodiment is obtained by applying the cooling device CA1 of the first embodiment (circulating liquid refrigerant by a pump) to a general refrigeration cycle in which a gas refrigerant circulates by a compressor. It is to be noted that matters not mentioned in the present embodiment are the same as those in the first embodiment.

[0067] The cooling device CA2 is configured to cool a cooling object 80 such as a heat generating portion. Figure 4As shown, the cooling device CA2 includes a refrigerant cycle system 21, in which a compressor 22, a condenser 23, an expansion valve 24, and a heat exchange container 25 are provided. The refrigerant cycle system 21 (cooling device CA2) forms a closed cycle system in which a cooling object 80 as a heat generating portion is stored in the heat exchange container 25 (inside). In the present embodiment, the entire cooling object 80 is stored in the heat exchange container 25, but the present invention is not limited thereto, and at least a portion of the cooling object 80 may be stored in the heat exchange container 25. Similar to the first embodiment, the refrigerant 10 circulating through the refrigerant cycle system 21 is a mixed refrigerant obtained by mixing a low boiling point refrigerant 11 (a first refrigerant of a first boiling point) and a high boiling point refrigerant 12 (a second refrigerant of a second boiling point higher than the first boiling point), and more specifically, a "non-azeotropic mixed refrigerant". It should be noted that, unlike the first embodiment, the high boiling point refrigerant 12 is in a gas phase when it is sent to the compressor 22.

[0068] The compressor 22 compresses the refrigerant in the gas phase (gas refrigerant 13) and sends it to the condenser 23. The condenser 23 condenses the gas refrigerant 13 by rejecting heat from the gas refrigerant 13 sent from the compressor 22 using a cooling medium (not shown) such as cooling water, thereby obtaining a refrigerant in the liquid phase (liquid refrigerant 14). The pressure of the liquid refrigerant 14 from the condenser 23 is reduced to a pressure near the saturated vapor pressure by the expansion valve 24, and the liquid refrigerant 14 is sent to the heat exchange container 25. In this way, the expansion valve 24 serves as a pressure reducer to reduce the pressure of the liquid refrigerant 14 from the condenser 23 and supply the liquid refrigerant 14 to the heat exchange container 25.

[0069] The heat exchange container 25 includes a heat exchange area 252 that performs heat exchange with a cooling object 80, and the cooling object 80 is built in the heat exchange area 252. When the cooling object 80 built in the heat exchange container 25 generates heat, the low-boiling-point refrigerant 11 in the liquid refrigerant 14 (mixed refrigerant) supplied to the heat exchange container 25 boils to cool the cooling object 80 by latent heat of evaporation, and the high-boiling-point refrigerant 12 performs convection cooling on the cooling object 80. In this way, the low-boiling-point refrigerant 11 performs boiling cooling on the cooling object 80 in the heat exchange area 252 in the heat exchange container to enter a gas phase state, and the high-boiling-point refrigerant 12 performs convection cooling on the cooling object 80 in the heat exchange area 252 in the heat exchange container in a liquid phase state. The low-boiling-point refrigerant 11 that passes through the heat exchange area 252 in the heat exchange container and is discharged from the heat exchange container 25 enters a liquid phase state or a gas-liquid mixed phase (two-phase) state according to the heat state of the cooling object 80. On the other hand, the high boiling point refrigerant 12 that passes through the heat exchange area 252 in the heat exchange container and is discharged from the heat exchange container 25 is always kept in a liquid phase regardless of the heat generation state of the cooling object 80. Note that the pressure sensor 26 is provided on the downstream side of the expansion valve 24, and the opening degree of the expansion valve 24 is controlled so that the pressure of the heat exchange container 25 (the pressure detected by the pressure sensor 26) is always close to the vapor pressure of the low boiling point refrigerant 11.

[0070] The refrigerant discharged from the heat exchange container 25 always includes the liquid refrigerant 14. Therefore, if the refrigerant discharged from the heat exchange container 25 is directly returned to the compressor 22, the compressor 22 cannot compress the refrigerant in the liquid phase state, and is thus damaged.

[0071] In order to deal with this problem, in the present embodiment, a gas-liquid separator 27 is provided between the heat exchange container 25 and the compressor 22, and the gas-liquid separator separates the refrigerant in the gas-liquid mixed phase state (mixed refrigerant) discharged from the heat exchange container 25 into a gas refrigerant 13 (refrigerant in the gas phase state) and a liquid refrigerant 14 (refrigerant in the liquid phase state). The refrigerant circulation system 21 includes a first path 211 for returning the liquid refrigerant 14 separated by the gas-liquid separator 27 to the compressor 22, and a second path 212 for returning the gas refrigerant 13 separated by the gas-liquid separator 27 to the compressor 22. The first path 211 is connected to the compressor 22 via a first vaporizer 28, and the first vaporizer vaporizes the liquid refrigerant 14 separated by the gas-liquid separator 27 to obtain a refrigerant in the gas phase state. On the other hand, the second path 212 is directly connected to the compressor 22.

[0072] As described above, in the present embodiment, the gas refrigerant 13 separated by the gas-liquid separator 27 is directly returned to the compressor 22 through the second path 212, and the liquid refrigerant 14 separated by the gas-liquid separator 27 is first sent to the first vaporizer 28 before returning to the compressor 22. The first vaporizer 28 branches the high-temperature gas refrigerant 15 on the downstream side of the compressor 22 and merges with the liquid refrigerant 14 separated by the gas-liquid separator 27 before returning to the condenser 23, and vaporizes the liquid refrigerant 14 through the high-temperature gas refrigerant 15 to return to the compressor 22.

[0073] The first vaporizer 28 includes a flow sensor 29 for detecting the flow rate of the liquid refrigerant 14, a throttle valve 30 for adjusting the flow rate of the high-temperature gas refrigerant 15, and a flow controller 31. The flow controller 31 controls the throttle valve 30 based on the flow rate of the liquid refrigerant 14 detected by the flow sensor 29 so that the flow rate of the high-temperature gas refrigerant 15 that merges with the liquid refrigerant 14 reaches a flow rate required to vaporize the liquid refrigerant 14. In this way, the first vaporizer 28 vaporizes the liquid refrigerant 14 by merging a portion of the gas refrigerant 15 (mixed refrigerant in a gas phase state) sent from the compressor 22 with the liquid refrigerant 14 separated by the gas-liquid separation unit 27 via the throttle valve 30. It is to be noted that an ultrasonic sensor is suitable as the flow sensor 29, but the present invention is not limited thereto.

[0074] The increase in the flow rate of the liquid refrigerant 14 included in the refrigerant discharged from the heat exchange container 25 indicates a decrease in the amount of heat generated by the cooling object 80 built into the heat exchange container 25, thereby making it possible to reduce the flow rate of the liquid refrigerant 14 to be supplied to the heat exchange container 25. The flow controller 31 controls the opening of the throttle valve 30 while controlling the opening (throttling) of the expansion valve 24, thereby appropriately controlling the flow balance between the liquid refrigerant 14 separated by the gas-liquid separation part 27 and the high-temperature gas refrigerant 15 from the compressor 22. In addition, the flow controller 31 can control the compression capacity (total flow rate of the refrigerant) of the compressor 22 via the inverter 32. This can prevent the liquid refrigerant 14 from returning to the compressor 22, and can maintain the refrigeration cycle after the heat load changes.

[0075] As described above, according to the present embodiment, a cooling device CA2 applied to a general refrigeration cycle can be realized. In the cooling device CA1 according to the first embodiment, in the case where the heat exchange container 7 recovers a large amount of heat and the condenser 2 discharges heat, two circulation systems through different refrigeration cycles are required. On the other hand, in the cooling device CA2 according to the present embodiment, heat can be discharged through one circulation system. Therefore, a cooling device CA2 that contributes to space saving and energy saving can be provided.

[0076] <Third Embodiment>

[0077] Figure 5 1 is a schematic circuit diagram showing the arrangement of a cooling device CA3 according to a third embodiment of the present invention. The cooling device CA3 according to this embodiment is obtained by improving the cooling device CA2 of the second embodiment. It should be noted that matters not mentioned in this embodiment are the same as those of the second embodiment.

[0078] In the present embodiment, a second vaporizer 33 is newly provided between the heat exchange container 25 and the gas-liquid separation part 27, and the second vaporizer vaporizes the refrigerant in the gas-liquid mixed phase state (mixed refrigerant) discharged from the heat exchange container 25. The second vaporizer 33 is implemented as, for example, a heat exchanger, which is provided in the condenser 23 and performs heat exchange between the high-temperature gas refrigerant 15 (mixed refrigerant in the gas phase state) sent from the compressor 22 and the refrigerant in the gas-liquid mixed phase state (mixed refrigerant) discharged from the heat exchange container 25. The liquid refrigerant 14 included in the refrigerant discharged from the heat exchange container 25 is heated by the high-temperature gas refrigerant 15 in the second vaporizer 33, and partially evaporates. On the other hand, the high-temperature gas refrigerant 15 is cooled by the latent heat of evaporation of the liquid refrigerant 14, and partially condenses.

[0079] According to the present embodiment, since the condenser 23 partially condenses the high-temperature gas refrigerant 15 sent from the compressor 22 by the liquid refrigerant 14 discharged from the heat exchange container 25, the heat discharged to the outside of the system can be reduced. In addition, by providing two vaporizers, the first vaporizer 28 and the second vaporizer 33, the risk of damage to the compressor 22 due to the mixing of the liquid refrigerant 14 can be further reduced.

[0080] <Fourth Embodiment>

[0081] Fig. 6A , Figure 6B and Figure 6C Each is a schematic circuit diagram showing the arrangement of a cooling device according to a fourth embodiment of the present invention. Each of the first to third embodiments is limited to the cooling of a cooling object 80 built into a heat exchange container 7 or 25. However, in a large-scale system such as an exposure device, there are many cooling objects (heating elements) in addition to the cooling object 80. The refrigerant that is not vaporized in the heat exchange container 7 or 25 or the liquid refrigerant 14 separated by the gas-liquid separation section 27 is in a liquid phase state, and therefore has the ability to perform boiling cooling on the cooling object. In the present embodiment, a new path is formed for cooling another cooling object (a cooling object different from the cooling object 80) that is not built into the heat exchange container 7 or 25.

[0082] Fig. 6AA case is shown in which a path for cooling a cooling object 81 different from the cooling object 80 is formed in the cooling device CA1 of the first embodiment. The cooling device CA1 includes a heat exchanger 34 on the downstream side of the heat exchange container 7. The heat exchanger 34 is in thermal contact with the cooling object 81, and performs heat exchange between the cooling object 81 and the refrigerant (mixed refrigerant) in a gas-liquid mixed phase state discharged from the heat exchange container 7, thereby cooling the cooling object 81. In the heat exchanger 34, the liquid refrigerant 14 that is not vaporized in the heat exchange container 7 boils by taking heat from the cooling object 81, thereby boiling-cooling the cooling object 81. It is to be noted that the refrigerant that has passed through the heat exchanger 34 returns to the condenser 2 in a gas-liquid mixed phase state, is cooled by the condenser 2 to undergo a phase change, and is then recycled as the liquid refrigerant 14.

[0083] Figure 6B The case where a path for cooling a cooling object 81 different from the cooling object 80 is formed in the cooling device CA2 of the second embodiment is shown. The cooling device CA2 includes a heat exchanger 34 in the first path 211 through which the liquid refrigerant 14 separated by the gas-liquid separation part 27 on the downstream side of the heat exchange container 25 flows. The heat exchanger 34 thermally contacts the cooling object 81, and performs heat exchange between the cooling object 81 and the liquid refrigerant 14 separated by the gas-liquid separation part 27, thereby cooling the cooling object 81. In the heat exchanger 34, the liquid refrigerant 14 separated by the gas-liquid separation part 27 boils by taking heat from the cooling object 81, thereby performing boiling cooling on the cooling object 81. It is to be noted that the refrigerant that has passed through the heat exchanger 34 is sent to the first vaporizer 28 in a gas phase state or a gas-liquid mixed phase state, is completely vaporized in the first vaporizer 28, and is returned to the compressor 22 as the gas refrigerant 13 for recirculation.

[0084] Figure 6CThe case where a path for cooling a cooling object 81 different from the cooling object 80 is formed in the cooling device CA3 of the third embodiment is shown. In the cooling device CA3, the first path 211 through which the liquid refrigerant 14 separated by the gas-liquid separation unit 27 flows is branched into a third path 213 and a fourth path 214. The third path 213 is a path to the second vaporizer 33 via the expansion valve 35 and the heat exchanger 34, and the fourth path 214 is a path to the second vaporizer 33 via the throttle valve 36. In this system, the pressure of the liquid refrigerant 14 is adjusted to a predetermined vapor pressure via the expansion valve 35. This is equivalent to the adjustment of the boiling point of the liquid refrigerant 14, and thereby the cooling object 81 can be cooled to a predetermined temperature. Therefore, this is particularly preferred in the case where the cooling object 81 requires temperature management. It should be noted that the same arrangement can be applied to the cooling device CA1 of the first embodiment or the cooling device CA2 of the second embodiment.

[0085] According to the present embodiment, the cooling object 81 different from the cooling object 80 built into the heat exchange container 7 or 25 can be boiling-cooled using the high-boiling-point refrigerant 12. Therefore, similar to a general refrigeration cycle, the cooling device according to the present embodiment can effectively cool the entire large system (e.g., exposure device) by one refrigerant circulation system.

[0086] <Fifth Embodiment>

[0087] The following will refer to Figure 7 , Figure 8 and Fig. 9 A semiconductor manufacturing apparatus to which the cooling apparatus CA1 , CA2 , or CA3 is applicable is exemplarily described, as well as a semiconductor manufacturing apparatus to which the cooling apparatus CA1 is applied in the present embodiment.

[0088] Figure 7 1 is a schematic diagram showing the arrangement of a semiconductor manufacturing apparatus, and more specifically showing the arrangement of an exposure apparatus 100 as an example of a pattern forming apparatus. The exposure apparatus 100 is configured to transfer a pattern of an original plate 101 to a photosensitive layer supplied (applied) to a substrate 102 through a projection optical system 140. The exposure apparatus 100 includes an illumination optical system 150 that illuminates the original plate 101, the projection optical system 140, a substrate positioning mechanism SPM that positions the substrate 102, and an original plate positioning mechanism (not shown) that positions the original plate 101.

[0089] The substrate positioning mechanism SPM includes a substrate stage 110 that supports a substrate chuck that holds a substrate 102, a driving mechanism 120 that drives the substrate stage 110, and a base member 130 that supports the driving mechanism 120. The driving mechanism 120 includes an actuator that includes a mover 122 that moves together with the substrate stage 110 and a stator 124 that is fixed to the base member 130. The stator 124 includes a coil (coil wire) that is a cooling target 80 of the cooling device CA1. The cooling device CA1 is configured to cool the coil of the stator 124 that serves as the cooling target 80.

[0090] Figure 8 1 is a schematic diagram showing the arrangement of a semiconductor manufacturing apparatus, and more specifically showing the arrangement of an imprint apparatus 200 as an example of a pattern forming apparatus. The imprint apparatus 200 is configured to transfer a pattern of an original plate 101 (mold) to an imprint material arranged (supplied) on a substrate 102. The imprint apparatus 200 includes an original plate driving mechanism 160 that drives the original plate 101, a substrate positioning mechanism SPM that drives the substrate 102, and a curing unit 170 that cures the imprint material arranged on the substrate 102.

[0091] At least one of the original plate driving mechanism 160 and the substrate positioning mechanism SPM can align the pattern area of ​​the original plate 101 and the irradiation area of ​​the substrate 102. At least one of the original plate driving mechanism 160 and the substrate positioning mechanism SPM can bring the pattern area of ​​the original plate 101 and the imprint material arranged on the substrate 102 into contact with each other, and separate the pattern area of ​​the original plate 101 and the imprint material arranged on the substrate 102.

[0092] When the imprint material disposed on the substrate 102 and the pattern area of ​​the original plate 101 are in contact with each other, the imprint apparatus 200 causes the curing unit 170 to cure the imprint material, and separates the cured imprint material from the original plate 101. In this way, a pattern made of a cured product of the imprint material is formed on the substrate 102. In other words, the pattern of the original plate 101 is transferred to the imprint material disposed on the substrate 102.

[0093] As described above, the substrate positioning mechanism SPM includes a substrate stage 110 that supports a substrate chuck that holds the substrate 102, a drive mechanism 120 that drives the substrate stage 110, and a base member 130 that supports the drive mechanism 120. The drive mechanism 120 includes an actuator that includes a mover 122 that moves together with the substrate stage 110 and a stator 124 that is fixed to the base member 130. The stator 124 includes a coil (coil wire) that is a cooling target 80 of the cooling device CA1. The cooling device CA1 is configured to cool the coil of the stator 124 that serves as the cooling target 80.

[0094] Fig. 91 is a schematic diagram showing the arrangement of a plasma processing apparatus 300 as an example of a semiconductor manufacturing apparatus. The plasma processing apparatus 300 includes, for example, a CVD apparatus, an etching apparatus, or a sputtering apparatus. The plasma processing apparatus 300 includes a chamber 330 and an electrode structure used as one or more cooling objects 80a and 80b arranged in the chamber 330.

[0095] In the present embodiment, the substrate 302 is supported by the cooling object 80a. A gas for generating plasma is supplied to the chamber 330. When the plasma processing apparatus 300 is configured as a CVD apparatus, a deposition gas is supplied to the chamber 330. When the plasma processing apparatus 300 is configured as an etching apparatus, an etching gas is supplied to the chamber 330. When the plasma processing apparatus 300 is configured as a sputtering apparatus, a gas for generating plasma is supplied to the chamber 330, and a target is attached to an electrode structure serving as the cooling object 80b. The cooling device CA1 is configured to cool the cooling objects 80a and 80b.

[0096] <Sixth Embodiment>

[0097] The semiconductor manufacturing method as one aspect of the present invention includes a processing step of processing a substrate by a semiconductor manufacturing device represented by the above-mentioned exposure device 100, imprint device 200 and plasma processing device 300, and a step of processing the substrate processed in the processing step. The step of processing the substrate by the semiconductor manufacturing device includes, for example, a step of forming a pattern on the substrate, a step of forming a film on the substrate, or a step of etching the substrate or a film formed on the substrate. The step of processing the substrate includes, for example, a step of dividing (slicing) the substrate or a step of sealing the substrate. Compared with conventional methods, the semiconductor manufacturing method according to this embodiment is advantageous in at least one aspect of semiconductor performance, quality, productivity and production cost.

[0098] The present invention is not limited to the above-described embodiments, and various modifications and variations can be made within the spirit and scope of the present invention. Therefore, the following claims are made in order to inform the public of the scope of the present invention.

[0099] This application claims the benefit of Japanese Patent Application No. 2022-095225, filed on June 13, 2022, which is hereby incorporated by reference in its entirety.

Claims

1. A cooling device for cooling a cooling object, characterized in that: The cooling device comprises: a circulation system configured to circulate a refrigerant for cooling a cooling object, wherein a container is provided in the circulation system, the container including an area for heat exchange between the refrigerant and at least a portion of the cooling object, The refrigerant is a mixed refrigerant obtained by mixing a first refrigerant having a first boiling point with a second refrigerant having a second boiling point higher than the first boiling point, The circulation system circulates the mixed refrigerant so that the mixed refrigerant enters the container at a predetermined temperature, and The vapor pressure of the first refrigerant at the predetermined temperature is higher than the withstand pressure of the container.

2. The cooling device according to claim 1, characterized in that: The circulation system circulates the mixed refrigerant so that when the first refrigerant and the second refrigerant are in a liquid phase, the area is exposed to the mixed refrigerant that has entered the container, and the mixed refrigerant discharged from the container includes a portion of the first refrigerant in a gas phase and the second refrigerant in a liquid phase.

3. The cooling device according to claim 1, characterized in that: The first refrigerant and the second refrigerant are mixed in such a mixing ratio that the first refrigerant boils and cools the cooling object in the region to enter a gas phase state, and the second refrigerant convectionally cools the cooling object in a liquid phase state in the region and compresses the first refrigerant in a gas phase state.

4. The cooling device according to claim 1, characterized in that: The mixed refrigerant is a non-azeotropic mixed refrigerant.

5. The cooling device according to claim 1, characterized in that: A compressor, a condenser, a pressure reducer and a gas-liquid separator are provided in the circulation system, the compressor is configured to compress a mixed refrigerant in a gas phase state and send out the mixed refrigerant, the condenser is configured to condense the mixed refrigerant in a gas phase state sent out from the compressor to obtain a mixed refrigerant in a liquid phase state, the pressure reducer is configured to reduce the pressure of the mixed refrigerant in a liquid phase state from the condenser and supply the mixed refrigerant to the container, and the gas-liquid separator is configured to separate the mixed refrigerant in a gas-liquid mixed phase state discharged from the container into a refrigerant in a gas phase state and a refrigerant in a liquid phase state, The circulation system includes a first path for returning the refrigerant in a liquid phase separated by the gas-liquid separator to the compressor and a second path for returning the refrigerant in a gas phase separated by the gas-liquid separator to the compressor. The first path is connected to the compressor via a first vaporizer configured to vaporize the refrigerant in the liquid phase separated by the gas-liquid separator to obtain the refrigerant in the gas phase, and The second path is directly connected to the compressor.

6. The cooling device according to claim 5, characterized in that: The first vaporizer vaporizes the liquid-phase refrigerant by causing a part of the mixed refrigerant in the gas-phase state sent from the compressor to merge with the liquid-phase refrigerant separated by the gas-liquid separation portion through a throttle valve.

7. The cooling device according to claim 5, characterized in that: The system further includes a second vaporizer disposed between the container and the gas-liquid separation unit and configured to vaporize the mixed refrigerant in a gas-liquid mixed phase state discharged from the container.

8. The cooling device according to claim 7, characterized in that: The second vaporizer includes a heat exchanger provided in the condenser and configured to perform heat exchange between the mixed refrigerant in a gas phase state sent from the compressor and the mixed refrigerant in a gas-liquid mixed phase state discharged from the container.

9. The cooling device according to claim 5, characterized in that: A heat exchanger is further included, the heat exchanger being configured to cool a cooling object different from the cooling object by exchanging heat between the cooling object different from the cooling object and the refrigerant in a liquid phase separated by the gas-liquid separation portion.

10. The cooling device according to claim 1, characterized in that: A heater is provided in the circulation system, and the heater is configured to heat the mixed refrigerant so that the temperature of the mixed refrigerant reaches the predetermined temperature.

11. The cooling device according to claim 1, characterized in that: A condenser, a pump and a pressure reducer are provided in the circulation system, the condenser is configured to condense the mixed refrigerant in a gas-liquid mixed phase state discharged from the container to obtain a mixed refrigerant in a liquid phase state, the pump is configured to deliver the mixed refrigerant in a liquid phase state from the condenser, and the pressure reducer is configured to reduce the pressure of the mixed refrigerant in a liquid phase state from the pump and supply the mixed refrigerant to the container.

12. The cooling device according to claim 11, characterized in that A heat exchanger is also included, the heat exchanger being configured to cool a cooling object different from the cooling object by exchanging heat between the cooling object different from the cooling object and the mixed refrigerant in a gas-liquid mixed phase state discharged from the container.

13. The cooling device according to claim 1, characterized in that: The first refrigerant is one of R1234zeE and R-1234yf.

14. A semiconductor manufacturing device comprising a heat generating unit, characterized in that: The semiconductor manufacturing device comprises: The cooling device according to claim 1, The cooling device is configured to cool the heat generating portion as a cooling target.

15. The semiconductor manufacturing device according to claim 14, characterized in that: The semiconductor manufacturing apparatus is formed as a pattern forming apparatus configured to form a pattern.

16. A semiconductor manufacturing method, characterized in that: The semiconductor manufacturing method comprises: A processing step of processing a substrate by the semiconductor manufacturing apparatus according to claim 14; and A step of processing the substrate processed in the above processing step.

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