Multi-refrigeration-cycle apparatus

Abstract

A multi-stage refrigeration cycle apparatus is provided, which can reduce the installation area of ​​equipment installed in an auxiliary room and shorten the piping used to transfer cooling medium to a semiconductor device manufacturing apparatus. The multi-stage refrigeration cycle apparatus (2) includes: a first refrigeration cycle (5) for circulating a first refrigerant, the first refrigerant exchanging heat with a cooling medium used to cool the semiconductor device manufacturing apparatus (1); and a second refrigeration cycle (6) for circulating a second refrigerant, the second refrigerant exchanging heat with the first refrigerant, at least a portion of the first refrigeration cycle (5) being disposed in a cleanroom where the semiconductor device manufacturing apparatus (1) is installed, and the second refrigeration cycle (6) being disposed in an auxiliary room.

Description

[Technical Field]

[0001] The present invention relates to a multi-stage refrigeration cycle apparatus comprising a low-temperature side refrigeration cycle and a high-temperature side refrigeration cycle, and more particularly to a multi-stage refrigeration cycle apparatus used in the cooling of semiconductor device manufacturing apparatus such as etching apparatus. [Previous Technology]

[0002] To expand memory capacity, layering is continuously being promoted as a technological innovation of 3D-NAND. Due to the layering, the processing time consumed in the etching process increases, and the reduction in throughput becomes a problem. In order to shorten the etching processing time and improve throughput, it is effective to cool the processing chamber of the etching device to a low temperature of about -30°C to -120°C.

[0003] Therefore, in order to achieve low temperatures of around -30℃ to -120℃, refrigeration devices such as binary refrigeration cycle devices have been used since the beginning of the year, and these have been commercialized by many companies. (Existing technical literature, patent literature)

[0004] Patent Document 1: Japanese Patent Application Publication No. 2012-193908; Patent Document 2: Japanese Patent Application Publication No. 2013-64559; Patent Document 3: International Publication No. 2012 / 128229

[0005] However, in these binary refrigeration cycle units, the number of devices increases compared to single-stage refrigeration cycle units, and the piping connecting these devices also increases, so inevitably the overall size of the unit increases. As shown in Figure 10, the typical setup of a semiconductor device manufacturing apparatus is as follows: the process chamber responsible for semiconductor device processing (e.g., the processing chamber of the etching apparatus) is located in a clean room, and the binary refrigeration cycle unit that cools the process chamber is located in a different area from the clean room, namely, the sub-fabrication area where various peripheral equipment is located, commonly referred to as the sub-fabrication area.

[0006] In most cases, the cleanroom and auxiliary room are located upstairs and downstairs. The area occupied by equipment in the auxiliary room should, in principle, not exceed the area occupied by the semiconductor device manufacturing equipment upstairs. Furthermore, there are multiple devices located in the auxiliary room; therefore, minimizing the area occupied by each device is a fundamental issue. However, the number of layers in the stacked structure of semiconductor device manufacturing equipment is increasing, and consequently, it is anticipated that binary refrigeration cycle equipment will become larger in the future.

[0007] In addition to the problems mentioned above, the piping used to transport ultra-low temperature cooling media needs to be covered with insulation material of appropriate thickness for preventing condensation and providing thermal insulation, which increases the labor and cost of construction. Moreover, not only is space required for such piping over a long distance from the auxiliary room to the clean room, but the longer the piping, the easier it is for the temperature of the surrounding gas to be transferred to the cooling medium inside the piping (resulting in a lower cooling effect).

[0008] Furthermore, the temperature of the cooling medium used in the cooling of semiconductor device manufacturing equipment varies significantly depending on the manufacturing process, and correspondingly, the temperature of the cooling medium in the refrigeration unit is also prone to fluctuation. As a result, there are situations where the operation of the refrigeration unit becomes unstable and the semiconductor device manufacturing equipment cannot be properly cooled. [Summary of the Invention]

[0009] Therefore, the present invention provides a multi-element refrigeration circulation apparatus that can reduce the installation area of ​​equipment installed in the auxiliary room and shorten the piping used to transfer the cooling medium to the semiconductor device manufacturing apparatus. Furthermore, the present invention provides a multi-element refrigeration circulation apparatus capable of achieving stable operation and proper cooling of the semiconductor device manufacturing apparatus.

[0010] In one embodiment, a multi-stage refrigeration cycle apparatus is provided for cooling a semiconductor device manufacturing apparatus, comprising: a first refrigeration cycle for supplying a first refrigerant, the first refrigerant exchanging heat with a cooling medium for cooling the semiconductor device manufacturing apparatus; and a second refrigeration cycle for supplying a second refrigerant, the second refrigerant exchanging heat with the first refrigerant, at least a portion of the first refrigeration cycle being disposed in a cleanroom in which the semiconductor device manufacturing apparatus is disposed, and the second refrigeration cycle being disposed in an auxiliary room.

[0011] According to the present invention, the constituent elements of the multi-stage refrigeration cycle apparatus are divided into two parts and respectively arranged in a cleanroom and an auxiliary room, thereby reducing the installation area of ​​the equipment installed in the auxiliary room. Furthermore, since at least a portion of the first refrigeration cycle is arranged in the cleanroom, the cooling piping used to transfer the ultra-low temperature cooling medium from the first refrigeration cycle to the semiconductor device manufacturing apparatus (e.g., the processing chamber of an etching apparatus) can be shortened. As a result, the space required for cooling piping can be reduced, and the cooling efficiency is improved.

[0012] In one embodiment, the entire first refrigeration cycle is configured within the cleanroom. According to the present invention, the installation area within the auxiliary room can be further reduced.

[0013] In one embodiment, the first refrigeration cycle includes: a first evaporator configured to exchange heat between the cooling medium and the first refrigerant to generate a gaseous first refrigerant; a first compressor configured to compress the gaseous first refrigerant; a first condenser configured to condense the compressed gaseous first refrigerant to generate a liquid first refrigerant; and a first expansion mechanism disposed between the first condenser and the first evaporator to reduce the pressure and temperature of the first refrigerant. The first evaporator and the first expansion mechanism are disposed in the cleanroom, and the first compressor and the first condenser are disposed in the auxiliary room. According to the present invention, the first compressor and the first condenser are disposed in the auxiliary room downstairs, and the first evaporator and the first expansion mechanism are disposed in the cleanroom upstairs. Therefore, lubricating oil leaking from the first compressor into the first refrigerant will not remain in the first evaporator and can return to the first compressor under its own gravity.

[0014] In one embodiment, the aforementioned multi-stage refrigeration cycle apparatus further includes an intermediate medium circulation pipe that circulates an intermediate medium between the first refrigeration cycle and the second refrigeration cycle, the intermediate medium circulation pipe extending between the first refrigeration cycle and the second refrigeration cycle. According to the present invention, the first refrigerant of the first refrigeration cycle and the second refrigerant of the second refrigeration cycle exchange heat via an intermediate medium. For the intermediate medium, as long as the heat of the first refrigerant can be transferred to the second refrigerant, a fluid that is easier to handle than the first and second refrigerants can be used. Therefore, for the intermediate medium circulation pipe, flexible piping such as resin tubes can be used. As a result, manufacturing costs can be reduced, and the configuration freedom of the first and second refrigeration cycles is increased. Since the temperature of the intermediate medium (e.g., 0°C to -80°C) is higher than the temperature of the cooling medium (e.g., -30°C to -120°C), the insulation material covering the intermediate medium circulation pipe can be simpler compared to the insulation material covering the cooling piping. Furthermore, the intermediate medium, due to its heat capacity commensurate with its volume, also functions as a thermal buffer between the first and second refrigerants. Typically, the temperature of the cooling medium used in the cooling of a semiconductor device manufacturing apparatus fluctuates, and correspondingly, the temperature of the first refrigerant also tends to fluctuate. Because the intermediate medium can absorb such temperature fluctuations of the first refrigerant, it can stabilize the operation of the multi-stage refrigeration cycle unit. As a result, the multi-stage refrigeration cycle unit can supply a cooling medium at a stable temperature to the semiconductor device manufacturing apparatus.

[0015] In one embodiment, the aforementioned multi-element refrigeration cycle device further includes a buffer tank connected to the aforementioned intermediate medium circulation pipeline. According to the present invention, the heat capacity of the intermediate medium can be increased, and the operation of the multi-element refrigeration cycle device can be further stabilized.

[0016] In one embodiment, the intermediate medium is a brine (antifreeze). According to the present invention, inexpensive piping with flexibility, such as resin pipes, can be used for the intermediate medium circulation pipeline. As a result, manufacturing costs can be reduced, and the flexibility in configuring the first and second refrigeration cycles is increased.

[0017] In one embodiment, the aforementioned multi-stage refrigeration cycle apparatus further includes a cascade condenser for heat exchange between the first refrigerant and the second refrigerant. According to the present invention, since the condenser of the first refrigeration cycle in the cascade condenser also serves as the evaporator of the second refrigeration cycle, the number of heat exchangers can be reduced, and the installation area of ​​the multi-stage refrigeration cycle apparatus can be reduced.

[0018] In one embodiment, the first refrigeration cycle comprises: a first evaporator configured to exchange heat between the cooling medium and the first refrigerant to generate a gaseous first refrigerant; a first compressor configured to compress the gaseous first refrigerant; a first condenser configured to condense the compressed gaseous first refrigerant to generate a liquid first refrigerant; and a heat exchanger disposed between the first compressor and the first condenser for cooling the compressed gaseous first refrigerant.

[0019] According to the present invention, since the first refrigerant in the gaseous phase is pre-cooled before entering the first condenser, the cooling heat required in the first condenser is reduced. That is, since the cooling heat is reduced due to the use of an intermediate medium, the refrigeration capacity required for the second refrigeration cycle can be smaller. This results in a reduction in the power consumption of the second refrigeration cycle, which in turn improves the operating efficiency of the multi-stage refrigeration cycle apparatus. In addition, since the refrigeration capacity of the second refrigeration cycle can be reduced, the installation area of ​​the equipment can be reduced. Moreover, the cooling water or refrigerant (antifreeze) used in the cooling process is discharged from the heat exchanger after being heated, so it can be used for other purposes requiring heating, and the power consumption for heating can also be reduced.

[0020] In one embodiment, a multi-stage refrigeration cycle apparatus is provided for cooling a semiconductor device manufacturing apparatus, comprising: a first refrigeration cycle for supplying a first refrigerant, the first refrigerant exchanging heat with a cooling medium for cooling the semiconductor device manufacturing apparatus; a second refrigeration cycle for supplying a second refrigerant, the second refrigerant exchanging heat with the first refrigerant; and an intermediate medium circulation pipe for circulating an intermediate medium between the first refrigeration cycle and the second refrigeration cycle.

[0021] In one embodiment, the intermediate medium circulation pipe extends between the condenser of the first refrigeration cycle and the evaporator of the second refrigeration cycle. In one embodiment, the multi-stage refrigeration cycle device further includes a buffer tank connected to the intermediate medium circulation pipe. In one embodiment, the intermediate medium is a refrigerant (antifreeze). [Effects of the Invention]

[0022] According to the present invention, the installation area of ​​the equipment installed in the auxiliary room can be reduced, and the piping for transferring the cooling medium to the semiconductor device manufacturing apparatus can be shortened, thereby reducing the space required for cooling piping and improving cooling efficiency.

[0023] According to the present invention, the intermediate medium can absorb temperature fluctuations of the cooling medium used in the cooling of the semiconductor device manufacturing apparatus, thereby stabilizing the operation of the multi-stage refrigeration cycle apparatus. As a result, the multi-stage refrigeration cycle apparatus can supply a cooling medium at a stable temperature to the semiconductor device manufacturing apparatus, thereby properly cooling the semiconductor device manufacturing apparatus.

Implementation Method

[0025] Hereinafter, embodiments of the present invention will be described with reference to drawings. FIG1 is a schematic diagram showing one embodiment of a multi-element refrigeration cycle apparatus for cooling a semiconductor device manufacturing apparatus. In the embodiment shown in FIG1, the semiconductor device manufacturing apparatus 1 is an etching apparatus having a processing chamber. The semiconductor device manufacturing apparatus 1 is disposed in a cleanroom, and a portion of the multi-element refrigeration cycle apparatus 2 is disposed in an auxiliary room located below the cleanroom. The cleanroom is on the upper floor, and the auxiliary room is on the lower floor.

[0026] The multi-element refrigeration cycle device 2 is connected to the semiconductor device manufacturing apparatus 1 via cooling piping 3. The multi-element refrigeration cycle device 2 supplies cooling medium to the semiconductor device manufacturing apparatus 1 (e.g., the processing chamber of an etching apparatus) via cooling piping 3, thereby cooling the semiconductor device manufacturing apparatus 1. The cooling medium circulates between the semiconductor device manufacturing apparatus 1 and the multi-element refrigeration cycle device 2. That is, the low-temperature (e.g., -30°C to -120°C) cooling medium generated by the multi-element refrigeration cycle device 2 is supplied to the semiconductor device manufacturing apparatus 1 via cooling piping 3, and the cooling medium used in the cooling of the semiconductor device manufacturing apparatus 1 is returned to the multi-element refrigeration cycle device 2 via cooling piping 3.

[0027] The multi-stage refrigeration cycle device 2 includes a first refrigeration cycle 5 for a first refrigerant cycle that exchanges heat with a cooling medium, and a second refrigeration cycle 6 for a second refrigerant cycle that exchanges heat with the first refrigerant. Therefore, the multi-stage refrigeration cycle device 2 of this embodiment is a binary refrigeration cycle device. In one embodiment, the multi-stage refrigeration cycle device 2 may also include three or more refrigeration cycles.

[0028] The first refrigeration cycle 5 is entirely housed within the cleanroom, and the second refrigeration cycle 6 is entirely housed in an auxiliary room located below the cleanroom. The cleanroom is equipped with a metal floor 7, such as a grating, and a subfloor space 9 exists beneath the floor 7. This subfloor space 9 is part of the cleanroom. The semiconductor device manufacturing apparatus 1 is mounted on the floor 7, and the first refrigeration cycle 5 is located in the surrounding space of the semiconductor device manufacturing apparatus 1, within the subfloor space 9, etc.

[0029] According to this embodiment, since the first freezing cycle 5 and the second freezing cycle 6, which are components of the multi-element freezing cycle apparatus 2, are respectively arranged in a clean room and an auxiliary room, the installation area of ​​the equipment installed in the auxiliary room can be reduced. Furthermore, since the first freezing cycle 5 is arranged in a clean room, the cooling piping 3 used to transfer the ultra-low temperature cooling medium from the first freezing cycle 5 to the semiconductor device manufacturing apparatus 1 (e.g., the processing chamber of an etching apparatus) can be shortened. As a result, the space required for the cooling piping 3 can be reduced, and the cooling efficiency is improved.

[0030] Figure 2 is a schematic diagram showing the detailed structure of one embodiment of the multi-stage refrigeration cycle device 2. As shown in Figure 2, the first refrigeration cycle 5 includes a first evaporator 11 for evaporating a liquid first refrigerant (refrigerant liquid) to generate a gaseous first refrigerant (refrigerant gas), a first compressor 12 for compressing the gaseous first refrigerant, and a first condenser 14 for condensing the compressed gaseous first refrigerant to generate a liquid first refrigerant. The first evaporator 11, the first compressor 12, and the first condenser 14 are connected by a first refrigerant piping 16. The first refrigerant circulates in the first evaporator 11, the first compressor 12, and the first condenser 14 through the first refrigerant piping 16.

[0031] The first refrigeration cycle 5 further includes a first expansion valve 17, which serves as a first expansion mechanism, located between the first evaporator 11 and the first condenser 14. The first expansion valve 17 is installed on the portion of the first refrigerant piping 16 extending between the first evaporator 11 and the first condenser 14. The first refrigerant flowing from the first condenser 14 to the first evaporator 11 passes through the first expansion valve 17, thereby reducing the pressure and temperature of the first refrigerant. The first refrigerant that has passed through the first expansion valve 17 flows into the first evaporator 11.

[0032] Cooling pipe 3 is connected to the first evaporator 11, where heat exchange occurs between the cooling medium and the first refrigerant. As a result of this heat exchange, the cooling medium is cooled to a low temperature (e.g., -30°C to -120°C), while the first refrigerant is heated by the cooling medium and evaporates into refrigerant gas. The cooled cooling medium is transported to the semiconductor device manufacturing apparatus 1 via cooling pipe 3, and the refrigerant gas is transported to the first compressor 12 via the first refrigerant pipe 16. The first compressor 12 compresses the refrigerant gas and transports the compressed refrigerant gas to the first condenser 14. In the first condenser 14, as described later, the refrigerant gas condenses into refrigerant liquid.

[0033] The second refrigeration cycle 6 includes a second evaporator 21 for evaporating a liquid second refrigerant (refrigerant liquid) to generate a gaseous second refrigerant (refrigerant gas), a second compressor 22 for compressing the gaseous second refrigerant, and a second condenser 24 for condensing the compressed gaseous second refrigerant to generate a liquid second refrigerant. The second evaporator 21, the second compressor 22, and the second condenser 24 are connected by a second refrigerant piping 26. The second refrigerant circulates in the second evaporator 21, the second compressor 22, and the second condenser 24 through the second refrigerant piping 26.

[0034] The multi-stage refrigeration cycle unit 2 further includes an intermediate medium circulation pipe 31 for circulating the intermediate medium between the first refrigeration cycle 5 and the second refrigeration cycle 6. The intermediate medium circulation pipe 31 is connected to the first refrigeration cycle 5 and the second refrigeration cycle 6. More specifically, the intermediate medium circulation pipe 31 has a conveying pipe 31A for conveying the intermediate medium from the second evaporator 21 of the second refrigeration cycle 6 to the first condenser 14 of the first refrigeration cycle 5, and a return pipe 31B for returning the intermediate medium from the first condenser 14 of the first refrigeration cycle 5 to the second evaporator 21 of the second refrigeration cycle 6. One end of the conveying pipe 31A is connected to the first condenser 14, and the other end of the conveying pipe 31A is connected to the second evaporator 21. One end of the return pipe 31B is connected to the first condenser 14, and the other end of the return pipe 31B is connected to the second evaporator 21.

[0035] The intermediate medium circulates between the first condenser 14 of the first refrigeration cycle 5 and the second evaporator 21 of the second refrigeration cycle 6 via the intermediate medium circulation pipe 31. The gaseous first refrigerant (refrigerant gas) exchanges heat with the intermediate medium within the first condenser 14. As a result, the gaseous first refrigerant is cooled by the intermediate medium to become a liquid first refrigerant (refrigerant liquid). The intermediate medium is heated by the first refrigerant, causing its temperature to rise.

[0036] The intermediate medium, heated by the first refrigerant, exchanges heat with the liquid phase of the second refrigerant (refrigerant liquid) within the second evaporator 21. As a result, the liquid phase of the second refrigerant is heated by the intermediate medium to become a gaseous phase of the second refrigerant (refrigerant gas), while the intermediate medium is cooled by the second refrigerant, causing its temperature to decrease. The cooled intermediate medium is then transported to the first condenser 14 of the first refrigeration cycle 5 via the intermediate medium circulation pipe 31. The cooled intermediate medium exchanges heat with the first refrigerant within the first condenser 14. In this way, the intermediate medium circulates between the first condenser 14 of the first refrigeration cycle 5 and the second evaporator 21 of the second refrigeration cycle 6 via the intermediate medium circulation pipe 31. The temperature of the intermediate medium flowing from the second evaporator 21 toward the first condenser 14 is, for example, 0°C to -80°C.

[0037] In the second evaporator 21, the second refrigerant is heated by an intermediate medium and evaporates, becoming a refrigerant gas. This refrigerant gas is transported to the second compressor 22 via the second refrigerant piping 26. The second compressor 22 compresses the refrigerant gas and transports the compressed refrigerant gas to the second condenser 24. In the second condenser 24, heat exchange occurs between cooling water supplied by a cooling water source (not shown) and the refrigerant gas (the gaseous second refrigerant). As a result, the refrigerant gas condenses into a refrigerant liquid.

[0038] As described above, the first refrigerant in the first refrigeration cycle 5 and the second refrigerant in the second refrigeration cycle 6 exchange heat via an intermediate medium. The intermediate medium is a liquid of a different type than the first and second refrigerants. More specifically, the intermediate medium is a refrigerant (antifreeze) such as perfluorocarbon (PFC) liquid or ethylene glycol liquid. Therefore, the intermediate medium remains in the liquid phase and circulates in the intermediate medium circulation pipe 31.

[0039] For the intermediate medium, as long as the heat of the first refrigerant can be transferred to the second refrigerant, a heat transfer fluid (antifreeze) that is easier to handle than the first and second refrigerants can be used. Therefore, for the intermediate medium circulation pipe 31, inexpensive piping with flexibility, such as resin pipes, can be used. As a result, manufacturing costs can be reduced, and the configuration freedom of the first refrigeration cycle 5 and the second refrigeration cycle 6 is increased. In addition, since the temperature of the intermediate medium (e.g., 0°C to -80°C) is higher than the temperature of the cooling medium (e.g., -30°C to -120°C), the insulation material covering the intermediate medium circulation pipe 31 can be simpler compared to the insulation material covering the cooling piping 3.

[0040] Furthermore, the intermediate medium, having a heat capacity commensurate with its volume, also functions as a thermal buffer between the first and second refrigerants. Typically, the temperature of the cooling medium used in the semiconductor device manufacturing apparatus 1 fluctuates, and correspondingly, the temperature of the first refrigerant also tends to fluctuate. Because the intermediate medium can absorb such temperature fluctuations of the first refrigerant, it can stabilize the operation of the multi-stage refrigeration cycle apparatus 2. As a result, the multi-stage refrigeration cycle apparatus 2 can supply the semiconductor device manufacturing apparatus 1 with a cooling medium at a stable temperature.

[0041] The second refrigeration cycle 6 further includes a second expansion valve 27, which serves as a second expansion mechanism, located between the second evaporator 21 and the second condenser 24. The second expansion valve 27 is installed on the portion of the second refrigerant piping 26 extending between the second evaporator 21 and the second condenser 24. The second refrigerant flowing from the second condenser 24 to the second evaporator 21 passes through the second expansion valve 27, thereby reducing the pressure and temperature of the second refrigerant. The second refrigerant that has passed through the second expansion valve 27 flows into the second evaporator 21.

[0042] FIG3 is a schematic diagram showing the detailed structure of another embodiment of the multi-element refrigeration cycle device 2. The structures and operations of this embodiment, unless otherwise specified, are the same as those described with reference to FIGS. 1 and 2, therefore repeated descriptions are omitted. In the embodiment shown in FIG3, a portion of the first refrigeration cycle 5 is disposed in a cleanroom, and the other portions of the first refrigeration cycle 5 are disposed in an auxiliary room. In this embodiment, the first evaporator 11 and the first expansion valve 17 are disposed in the cleanroom, and the first compressor 12 and the first condenser 14 are disposed in the auxiliary room. The intermediate medium circulation pipeline 31 is also entirely disposed in the auxiliary room.

[0043] This embodiment is advantageous when the cleanroom area is small. Furthermore, according to this embodiment, the first compressor 12 and the first condenser 14 are arranged in the auxiliary room downstairs, and the first evaporator 11 is arranged in the cleanroom upstairs. Therefore, lubricating oil leaking from the first compressor 12 into the first refrigerant will not remain in the first evaporator 11, and can return to the first compressor 12 under its own gravity. Additionally, in the first refrigeration cycle 5, by arranging the first evaporator 11 and the first expansion valve 17, which are components that become colder, in the cleanroom, the cooling piping 3 used to transfer the cooling medium from the first refrigeration cycle 5 to the semiconductor device manufacturing apparatus 1 can be shortened.

[0044] As shown in FIG. 4, in one embodiment, the multi-stage refrigeration cycle device 2 may also include a buffer tank 32 connected to the intermediate medium circulation pipe 31. In the embodiment shown in FIG. 4, the buffer tank 32 is connected to a return pipe 31B for returning the intermediate medium from the first condenser 14 of the first refrigeration cycle 5 to the second evaporator 21 of the second refrigeration cycle 6. The buffer tank 32 is disposed in an auxiliary room with sufficient space. The intermediate medium exiting from the first condenser 14 of the first refrigeration cycle 5 is temporarily stored in the buffer tank 32, and then returned from the buffer tank 32 to the second evaporator 21 of the second refrigeration cycle 6.

[0045] According to this embodiment, since the volume of the intermediate medium can be increased accordingly to the volume of the buffer tank 32, the heat capacity of the intermediate medium is increased, which can further stabilize the operation of the multi-element refrigeration cycle device 2. The buffer tank 32 shown in FIG4 can also be incorporated into the embodiment of FIG3.

[0046] Figure 5 is a schematic diagram showing the detailed structure of another embodiment of the multi-stage refrigeration cycle device 2. The structures and operations of this embodiment, unless otherwise specified, are the same as those described with reference to Figure 2, therefore repeated descriptions are omitted. In the embodiment shown in Figure 5, the condenser of the first refrigeration cycle 5 and the evaporator of the second refrigeration cycle 6 are constituted by a common cascade condenser 40. The cascade condenser 40 is a heat exchanger that serves as both the condenser of the first refrigeration cycle 5 and the evaporator of the second refrigeration cycle 6, and is located in an auxiliary room. In one embodiment, if there is sufficient space in the cleanroom, the first evaporator 11, the first compressor 12, the first expansion valve 17, and the cascade condenser 40 of the first refrigeration cycle 5 can be located within the cleanroom.

[0047] In this embodiment, an intermediate medium circulation pipe 31 is not provided. The first refrigerant pipe 16 of the first refrigeration cycle 5 and the second refrigerant pipe 26 of the second refrigeration cycle 6 are both connected to the cascade condenser 40. The first refrigerant circulating in the first refrigeration cycle 5 and the second refrigerant circulating in the second refrigeration cycle 6 flow through the cascade condenser 40, where heat exchange occurs between the first and second refrigerants. Since the condenser of the first refrigeration cycle 5 in the cascade condenser 40 also serves as the evaporator of the second refrigeration cycle 6, the number of heat exchangers can be reduced, and the installation area of ​​the multi-element refrigeration cycle device 2 can be reduced.

[0048] Figure 6 is a schematic diagram showing the detailed structure of another embodiment of the multi-stage refrigeration cycle device 2. The structures and operations of this embodiment, unless otherwise described, are the same as those described with reference to Figure 2, therefore repeated descriptions are omitted. In this embodiment, a heat exchanger 50 is provided between the first compressor 12 and the first condenser 14 of the first refrigeration cycle 5. The heat exchanger 50 is connected to the portion of the first refrigerant piping 16 extending between the first compressor 12 and the first condenser 14. Coolant such as cooling water or a refrigerant (antifreeze) and the compressed gaseous first refrigerant flow in the heat exchanger 50, and heat exchange occurs between the coolant and the gaseous first refrigerant. The gaseous first refrigerant, cooled by heat exchange with the coolant, is introduced into the first condenser 14.

[0049] As such, since the gaseous first refrigerant is pre-cooled before entering the first condenser 14, the required cooling heat in the first condenser 14 is reduced. That is, since the cooling heat is reduced due to the use of an intermediate medium, the required refrigeration capacity for the second refrigeration cycle 6 can be smaller. This results in a reduction in the power consumption of the second refrigeration cycle 6, which in turn improves the operating efficiency of the multi-stage refrigeration cycle unit 2. In addition, since the refrigeration capacity of the second refrigeration cycle 6 can be reduced, the installation area of ​​the equipment can be reduced. Moreover, the coolant, such as cooling water or refrigerant (antifreeze), used in the cooling of the gaseous first refrigerant is heated and then discharged from the heat exchanger 50, so it can be used for other applications requiring heating, and the power consumption for heating can also be reduced.

[0050] The heat exchanger 50 can also be adapted to the embodiments described with reference to Figures 3 to 5. For example, the heat exchanger 50 can also be configured between the first compressor 12 and the cascade condenser 40 shown in Figure 5.

[0051] FIG7 is a schematic diagram showing the detailed structure of one embodiment of the multi-element refrigeration cycle apparatus 102. As shown in FIG7, the multi-element refrigeration cycle apparatus 102 is connected to the semiconductor device manufacturing apparatus 1 via cooling piping 103. The multi-element refrigeration cycle apparatus 102 supplies cooling medium to the semiconductor device manufacturing apparatus 1 (e.g., the processing chamber of an etching apparatus) via cooling piping 103, thereby cooling the semiconductor device manufacturing apparatus 1. The cooling medium circulates between the semiconductor device manufacturing apparatus 1 and the multi-element refrigeration cycle apparatus 102. That is, the low-temperature (e.g., -30°C to -120°C) cooling medium generated by the multi-element refrigeration cycle apparatus 102 is supplied to the semiconductor device manufacturing apparatus 1 via cooling piping 103, and the cooling medium used in the cooling of the semiconductor device manufacturing apparatus 1 is returned to the multi-element refrigeration cycle apparatus 102 via cooling piping 103.

[0052] The multi-stage refrigeration cycle apparatus 102 includes a first refrigeration cycle 105 for heat exchange with a first refrigerant cycle and a second refrigeration cycle 106 for heat exchange with the first refrigerant via an intermediate medium. Therefore, the multi-stage refrigeration cycle apparatus 102 of this embodiment is a binary refrigeration cycle apparatus. In one embodiment, the multi-stage refrigeration cycle apparatus 102 may also include three or more refrigeration cycles.

[0053] The first refrigeration cycle 105 includes a first evaporator 111 for evaporating a liquid first refrigerant (refrigerant liquid) to generate a gaseous first refrigerant (refrigerant gas), a first compressor 112 for compressing the gaseous first refrigerant, and a first condenser 114 for condensing the compressed gaseous first refrigerant to generate a liquid first refrigerant. The first evaporator 111, the first compressor 112, and the first condenser 114 are connected by a first refrigerant piping 116. The first refrigerant circulates in the first evaporator 111, the first compressor 112, and the first condenser 114 through the first refrigerant piping 116.

[0054] The first refrigeration cycle 105 further includes a first expansion valve 117, which serves as a first expansion mechanism, located between the first evaporator 111 and the first condenser 114. The first expansion valve 117 is installed in the portion of the first refrigerant piping 116 extending between the first evaporator 111 and the first condenser 114. The first refrigerant flowing from the first condenser 114 to the first evaporator 111 passes through the first expansion valve 117, thereby reducing the pressure and temperature of the first refrigerant. The first refrigerant that has passed through the first expansion valve 117 flows into the first evaporator 111.

[0055] Cooling pipe 103 is connected to the first evaporator 111, where heat exchange occurs between the cooling medium and the first refrigerant. As a result of this heat exchange, the cooling medium is cooled to a low temperature (e.g., -30°C to -120°C), while the first refrigerant is heated by the cooling medium and evaporates into refrigerant gas. The cooled cooling medium is transported to the semiconductor device manufacturing apparatus 1 via cooling pipe 103, and the refrigerant gas is transported to the first compressor 112 via the first refrigerant pipe 116. The first compressor 112 compresses the refrigerant gas and transports the compressed refrigerant gas to the first condenser 114. In the first condenser 114, as described later, the refrigerant gas condenses into refrigerant liquid.

[0056] The second refrigeration cycle 106 includes a second evaporator 121 for evaporating a liquid second refrigerant (refrigerant liquid) to generate a gaseous second refrigerant (refrigerant gas), a second compressor 122 for compressing the gaseous second refrigerant, and a second condenser 124 for condensing the compressed gaseous second refrigerant to generate a liquid second refrigerant. The second evaporator 121, the second compressor 122, and the second condenser 124 are connected by a second refrigerant piping 126. The second refrigerant circulates in the second evaporator 121, the second compressor 122, and the second condenser 124 through the second refrigerant piping 126.

[0057] The multi-stage refrigeration cycle device 102 further includes an intermediate medium circulation pipe 131 for circulating an intermediate medium between the first refrigeration cycle 105 and the second refrigeration cycle 106. The intermediate medium circulation pipe 131 is connected to the first refrigeration cycle 105 and the second refrigeration cycle 106. More specifically, the intermediate medium circulation pipe 131 has a delivery pipe 131A for conveying the intermediate medium from the second evaporator 121 of the second refrigeration cycle 106 to the first condenser 114 of the first refrigeration cycle 105, and a return pipe 131B for returning the intermediate medium from the first condenser 114 of the first refrigeration cycle 105 to the second evaporator 121 of the second refrigeration cycle 106. One end of the delivery pipe 131A is connected to the first condenser 114, and the other end of the delivery pipe 131A is connected to the second evaporator 121. One end of the return pipe 131B is connected to the first condenser 114, and the other end of the return pipe 131B is connected to the second evaporator 121.

[0058] The intermediate medium circulates between the first condenser 114 of the first refrigeration cycle 105 and the second evaporator 121 of the second refrigeration cycle 106 via the intermediate medium circulation pipe 131. The gaseous first refrigerant (refrigerant gas) exchanges heat with the intermediate medium within the first condenser 114. As a result, the gaseous first refrigerant is cooled by the intermediate medium to become a liquid first refrigerant (refrigerant liquid). The intermediate medium is heated by the first refrigerant, causing its temperature to rise.

[0059] The intermediate medium, heated by the first refrigerant, exchanges heat with the liquid phase of the second refrigerant (refrigerant liquid) within the second evaporator 121. As a result, the liquid phase of the second refrigerant is heated by the intermediate medium to become a gaseous phase of the second refrigerant (refrigerant gas), while the intermediate medium is cooled by the second refrigerant, causing its temperature to decrease. The cooled intermediate medium is then transported to the first condenser 114 of the first refrigeration cycle 105 via the intermediate medium circulation pipe 131. The cooled intermediate medium exchanges heat with the first refrigerant within the first condenser 114. In this way, the intermediate medium circulates between the first condenser 114 of the first refrigeration cycle 105 and the second evaporator 121 of the second refrigeration cycle 106 via the intermediate medium circulation pipe 131. The temperature of the intermediate medium flowing from the second evaporator 121 toward the first condenser 114 is, for example, 0°C to -80°C.

[0060] In the second evaporator 121, the second refrigerant is heated by an intermediate medium and evaporates into refrigerant gas. This refrigerant gas is transported to the second compressor 122 via the second refrigerant piping 126. The second compressor 122 compresses the refrigerant gas and transports the compressed refrigerant gas to the second condenser 124. In the second condenser 124, heat exchange occurs between cooling water supplied by a cooling water source (not shown) and the refrigerant gas (the gaseous second refrigerant). As a result, the refrigerant gas condenses into refrigerant liquid.

[0061] As described above, the first refrigerant in the first refrigeration cycle 105 and the second refrigerant in the second refrigeration cycle 106 exchange heat via an intermediate medium. The intermediate medium is a liquid of a different type than the first and second refrigerants. More specifically, the intermediate medium is a refrigerant (antifreeze) such as perfluorocarbon (PFC) liquid or ethylene glycol liquid. Therefore, the intermediate medium remains in the liquid phase and circulates in the intermediate medium circulation pipe 131.

[0062] For the intermediate medium, as long as the heat of the first refrigerant can be transferred to the second refrigerant, a heat transfer fluid (antifreeze) that is easier to handle than the first and second refrigerants can be used. Therefore, for the intermediate medium circulation pipe 131, inexpensive piping with flexibility, such as resin pipe, can be used. As a result, manufacturing costs can be reduced, and the configuration freedom of the first refrigeration cycle 105 and the second refrigeration cycle 106 is increased. In addition, since the temperature of the intermediate medium (e.g., 0°C to -80°C) is higher than the temperature of the cooling medium (e.g., -30°C to -120°C), the insulation material covering the intermediate medium circulation pipe 131 can be simpler than the insulation material covering the cooling piping 103.

[0063] Furthermore, the intermediate medium, having a heat capacity corresponding to its volume, also functions as a thermal buffer between the first and second refrigerants. Typically, the temperature of the cooling medium used in the cooling of the semiconductor device manufacturing apparatus 1 fluctuates, and correspondingly, the temperature of the first refrigerant also tends to fluctuate. Because the intermediate medium can absorb such temperature fluctuations of the first refrigerant, it can stabilize the operation of the multi-stage refrigeration cycle apparatus 102. As a result, the multi-stage refrigeration cycle apparatus 102 can supply the semiconductor device manufacturing apparatus 1 with a cooling medium at a stable temperature.

[0064] The second refrigeration cycle 106 further includes a second expansion valve 127, which serves as a second expansion mechanism, located between the second evaporator 121 and the second condenser 124. The second expansion valve 127 is installed in the portion of the second refrigerant piping 126 extending between the second evaporator 121 and the second condenser 124. The second refrigerant flowing from the second condenser 124 to the second evaporator 121 passes through the second expansion valve 127, thereby reducing the pressure and temperature of the second refrigerant. The second refrigerant that has passed through the second expansion valve 127 flows into the second evaporator 121.

[0065] As shown in FIG8, in one embodiment, the multi-stage refrigeration cycle device 102 may also include a buffer tank 132 connected to the intermediate medium circulation pipe 131. In the embodiment shown in FIG8, the buffer tank 132 is connected to a return pipe 131B for returning the intermediate medium from the first condenser 114 of the first refrigeration cycle 105 to the second evaporator 121 of the second refrigeration cycle 106. The buffer tank 132 is disposed in an auxiliary production room, commonly referred to as the auxiliary room, where there is sufficient space for various peripheral equipment. The intermediate medium exiting from the first condenser 114 of the first refrigeration cycle 105 is temporarily stored in the buffer tank 132 and then returned from the buffer tank 132 to the second evaporator 121 of the second refrigeration cycle 106.

[0066] According to this embodiment, the volume of the intermediate medium increases in proportion to the volume of the buffer tank 132, thereby increasing the heat capacity of the intermediate medium and enabling the operation of the multi-element refrigeration cycle device 102 to be further stabilized.

[0067] Figure 9 is a schematic diagram showing one embodiment of the configuration of the multi-stage refrigeration cycle apparatus. The semiconductor device manufacturing apparatus 1 (e.g., the processing chamber of an etching apparatus) is configured in a cleanroom, and a portion of the multi-stage refrigeration cycle apparatus 102 is configured in an auxiliary room located below the cleanroom. Typically, the cleanroom is on the upper floor, and the auxiliary room is on the lower floor.

[0068] The first refrigeration cycle 105 is entirely housed within the cleanroom, and the second refrigeration cycle 106 is entirely housed in an auxiliary room located below the cleanroom. A metal floor 7, such as a grid panel, is installed within the cleanroom, and a subfloor space 9 exists beneath the floor 7. This subfloor space 9 is part of the cleanroom. The semiconductor device manufacturing apparatus 1 is mounted on the floor 7, and the first refrigeration cycle 105 is located in the surrounding space of the semiconductor device manufacturing apparatus 1, within the subfloor space 9, etc.

[0069] Since the intermediate medium circulation pipe 131 can improve the configuration freedom of the first freezing cycle 105 and the second freezing cycle 106, as shown in FIG9, the first freezing cycle 105 and the second freezing cycle 106, which are components of the multi-element freezing cycle device 102, can be configured in the cleanroom and the auxiliary room, respectively. As a result, the installation area of ​​the equipment installed in the auxiliary room can be reduced. In addition, since the first freezing cycle 105 is configured in the cleanroom, the cooling piping 103 used to transfer the ultra-low temperature cooling medium from the first freezing cycle 105 to the semiconductor device manufacturing apparatus 1 (e.g., the processing chamber of the etching apparatus) can be shortened. As a result, the space used for the cooling piping 103 can be reduced, and the cooling efficiency can be improved.

[0070] Furthermore, by providing the intermediate medium circulation pipe 131, a second refrigeration cycle can be connected to multiple first refrigeration cycles. As a result, the installation area of ​​the equipment installed in the auxiliary room can be reduced, and the operating efficiency can also be improved.

[0071] Moreover, by having an intermediate medium circulation pipe 131, for example, a second refrigeration cycle can be added more easily even after the device has been put into use, and changes in cooling capacity (increase) and cooling temperature (decrease) can be flexibly addressed.

[0072] The above embodiments are described with the aim of enabling those skilled in the art to carry out the present invention. Various modifications of the above embodiments will be obvious to those skilled in the art, and the technical concept of the present invention can also be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is interpreted within the maximum scope of the technical concept defined by the claims. [Simplified Explanation of the Diagram]

[0024] FIG1 is a schematic diagram showing one embodiment of a multi-element refrigeration cycle apparatus for cooling a semiconductor device manufacturing apparatus. FIG2 is a schematic diagram showing a detailed structure of one embodiment of the multi-element refrigeration cycle apparatus. FIG3 is a schematic diagram showing a detailed structure of another embodiment of the multi-element refrigeration cycle apparatus. FIG4 is a schematic diagram showing a detailed structure of yet another embodiment of the multi-element refrigeration cycle apparatus. FIG5 is a schematic diagram showing a detailed structure of yet another embodiment of the multi-element refrigeration cycle apparatus. FIG6 is a schematic diagram showing a detailed structure of yet another embodiment of the multi-element refrigeration cycle apparatus. FIG7 is a schematic diagram showing a detailed structure of one embodiment of the multi-element refrigeration cycle apparatus. FIG8 is a schematic diagram showing a detailed structure of yet another embodiment of the multi-element refrigeration cycle apparatus. FIG9 is a schematic diagram showing one embodiment of the configuration of the multi-element refrigeration cycle apparatus. FIG10 is a schematic diagram for illustrating a conventional configuration of a semiconductor device manufacturing apparatus and a multi-element refrigeration cycle apparatus.

Claims

1. A multi-stage refrigeration cycle apparatus for cooling a semiconductor device manufacturing apparatus, comprising: a first refrigeration cycle for supplying a first refrigerant, the first refrigerant exchanging heat with a cooling medium for cooling the semiconductor device manufacturing apparatus; and a second refrigeration cycle for supplying a second refrigerant, the second refrigerant exchanging heat with the first refrigerant, at least a portion of the first refrigeration cycle being disposed in a cleanroom housing the semiconductor device manufacturing apparatus, and the second refrigeration cycle being disposed in a sub-fab.

2. The multi-element refrigeration cycle apparatus according to claim 1, wherein, The first refrigeration cycle is configured entirely within the cleanroom.

3. The multi-element refrigeration cycle apparatus according to claim 1, wherein, The first refrigeration cycle includes: a first evaporator configured to exchange heat between the cooling medium and the first refrigerant to generate a gaseous first refrigerant; a first compressor configured to compress the gaseous first refrigerant; a first condenser configured to condense the compressed gaseous first refrigerant to generate a liquid first refrigerant; and a first expansion mechanism disposed between the first condenser and the first evaporator to reduce the pressure and temperature of the first refrigerant. The first evaporator and the first expansion mechanism are disposed in the cleanroom, and the first compressor and the first condenser are disposed in the auxiliary room.

4. The multi-element refrigeration cycle apparatus according to claim 1, wherein, The multi-stage refrigeration cycle apparatus further includes an intermediate medium circulation pipe for circulating an intermediate medium between the first refrigeration cycle and the second refrigeration cycle, the intermediate medium circulation pipe extending between the first refrigeration cycle and the second refrigeration cycle.

5. The multi-element refrigeration cycle apparatus according to claim 4, wherein, The multi-component refrigeration circulation device also includes a buffer tank connected to the intermediate medium circulation pipeline.

6. The multi-element refrigeration cycle apparatus according to claim 4, wherein, The intermediate medium is a refrigerant (brine) (antifreeze).

7. The multi-element refrigeration cycle apparatus according to claim 1, wherein, It also includes a cascade condenser for heat exchange between the first refrigerant and the second refrigerant.

8. The multi-element refrigeration cycle apparatus according to claim 1, wherein, The first refrigeration cycle includes: a first evaporator configured to exchange heat between the cooling medium and the first refrigerant to generate a gaseous first refrigerant; a first compressor configured to compress the gaseous first refrigerant; and a first condenser configured to condense the compressed gaseous first refrigerant to generate a liquid first refrigerant. A heat exchanger, configured between the first compressor and the first condenser, is used to cool the compressed gaseous first refrigerant.

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