A wide-temperature-range variable-temperature cycling temperature control system for semiconductors

Abstract

The present invention discloses a temperature control system with variable temperature cycling in a wide temperature range for semiconductor use. It adopts a regenerative closed-cycle structure design. The main pipelines of the cold source unit and the distribution unit are respectively placed in the valve box, and the inside of the valve box is evacuated to form a vacuum environment, reducing the convective heat transfer of the residual gas molecules inside the pipeline, reducing the heat leakage of the cryogenic working fluid, ensuring the low return gas temperature of nitrogen, and thus maximizing the recovery of cold energy and energy-saving utilization. A throttle valve is provided in the distribution valve box, and the temperature in the distribution valve box is effectively further reduced by means of pressure reduction, effectively expanding the application temperature range of the system. At the same time, three-stage precooling pipelines are provided in the cold source valve box and the distribution valve box to perform staged precooling on the cold source valve box, the distribution valve box and the throttle valve at the initial stage of system operation, ensuring the low-temperature injection efficiency during the semiconductor production process.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor temperature control, and particularly relates to a wide-temperature-range variable-temperature cycle temperature control system for semiconductors. Background Art

[0002] With the continuous development of semiconductor manufacturing technology, a variable-temperature cycle temperature control system used for precisely controlling the temperature of a reaction chamber during semiconductor manufacturing is an essential key device in the semiconductor manufacturing process and is widely used in fields such as semiconductor manufacturing and testing. The variable-temperature cycle temperature control system is a self-balancing cycle device mainly composed of a heat exchanger, a circulation pump, a compressor, and a control system, and can continuously provide a low-temperature medium with controllable temperature, ensuring the process processing temperature in processes such as etching, ion implantation, diffusion, thin-film deposition, and chemical mechanical polishing in semiconductor manufacturing.

[0003] Currently, the variable-temperature cycle temperature control systems in the market generally have problems such as a narrow temperature range, small cooling capacity, poor temperature control accuracy, short equipment service life, and high operation difficulty, which bring certain limitations to the variable-temperature cycle temperature control performance required in the semiconductor production process and have a weak support ability for the applicability of high and low temperatures. Therefore, designing a variable-temperature cycle temperature control system with a wide temperature range, large cooling capacity, high temperature control accuracy, long life, and simple operation is of great significance in the semiconductor manufacturing field.

[0004] During the actual working process, the temperature control system usually includes a refrigeration unit and a distribution unit. Since semiconductor production equipment is large and the refrigeration unit and the distribution unit are far apart, the cooling capacity provided by the refrigeration machine of the refrigeration unit reaches the distribution unit through a long pipeline and then can be provided to the target disk, resulting in the cooling capacity reaching the target disk being difficult to meet the temperature requirements, and further resulting in poor temperature control accuracy. Summary of the Invention

[0005] To solve the technical problems in the background art, the present invention proposes a wide-temperature-range variable-temperature cycle temperature control system for semiconductors.

[0006] The wide-temperature-range variable-temperature cycle temperature control system for semiconductors proposed by the present invention includes: a low-temperature cold source unit and a low-temperature distribution unit;

[0007] The low-temperature distribution unit includes a distribution valve box and a second vacuum pump. The second vacuum pump is used to evacuate the distribution valve box. The distribution valve box is provided with a cold quantity outlet and a heat regeneration inlet connected to the target disk, as well as a second cold quantity inlet and a second heat regeneration outlet connected to the cold source valve box. Inside the distribution valve box, there are a low-temperature throttle valve, a secondary precooling pipeline, and a tertiary precooling pipeline. The low-temperature throttle valve is located on the pipeline between the cold quantity outlet and the second cold quantity inlet. The two ends of the secondary precooling pipeline are respectively connected to the pipeline upstream of the low-temperature throttle valve and the pipeline between the heat regeneration inlet and the second heat regeneration outlet. A secondary low-temperature switch valve V16 is provided on the secondary precooling pipeline. The two ends of the tertiary precooling pipeline are respectively connected to the pipeline downstream of the low-temperature throttle valve and the pipeline between the heat regeneration inlet and the second heat regeneration outlet. A tertiary low-temperature switch valve is provided on the tertiary precooling pipeline.

[0008] Preferably, the low-temperature cold source unit includes a cold source valve box, a refrigerator, a circulation pump, and a first vacuum pump. The first vacuum pump is used to evacuate the cold source valve box. The cold source valve box is provided with a first heat regeneration outlet and a first cold quantity inlet respectively connected to the input end and the output end of the refrigerator. Inside the cold source valve box, there are a heat regenerator, a first outlet switch valve V13, and a first inlet switch valve V14. The first outlet switch valve V13 is connected to the first cold quantity inlet. The first heat regeneration outlet is sequentially connected to the high-temperature channel of the heat regenerator, the circulation pump, the low-temperature channel of the heat regenerator, and the first inlet switch valve V14. Inside the cold source valve box, there is also a primary precooling pipeline. The two ends of the primary precooling pipeline are respectively connected to the pipeline upstream of the first outlet switch valve V13 and the pipeline downstream of the first outlet switch valve V13. A primary low-temperature switch valve V15 is provided on the primary precooling pipeline.

[0009] Preferably, during the primary precooling process, the first outlet switch valve V13 and the first inlet switch valve V14 are closed and the primary low-temperature switch valve V15 is opened. The working medium output from the output end of the refrigerator sequentially passes through the primary precooling pipeline, the low-temperature channel of the heat regenerator, the circulation pump, and the high-temperature channel of the heat regenerator and then returns to the input end of the refrigerator.

[0010] Preferably, during the secondary precooling process, the primary low-temperature switch valve V15 is closed, and the first outlet switch valve V13, the first inlet switch valve V14, and the secondary low-temperature switch valve V16 are opened. The working medium output from the output end of the refrigerator sequentially passes through the first outlet switch valve V13, the secondary precooling pipeline, the first inlet switch valve V14, the low-temperature channel of the heat regenerator, the circulation pump, and the high-temperature channel of the heat regenerator and then returns to the input end of the refrigerator.

[0011] Preferably, a tertiary low-temperature switch valve V17 is provided on the tertiary precooling pipeline. During the tertiary precooling process, the secondary low-temperature switch valve V16 is closed, and the tertiary low-temperature switch valve V17 is opened. The working medium output from the output end of the refrigerator sequentially passes through the first outlet switch valve V13, the low-temperature throttle valve, the tertiary precooling pipeline, the first inlet switch valve V14, the low-temperature channel of the heat regenerator, the circulation pump, and the high-temperature channel of the heat regenerator and then returns to the input end of the refrigerator.

[0012] Preferably, a third temperature sensor is provided on the pipeline between the low-temperature throttle valve and the three-stage low-temperature switching valve V17.

[0013] Preferably, a first temperature sensor is provided on the pipeline between the second cold quantity inlet and the low-temperature throttle valve.

[0014] Preferably, the low-temperature distribution unit further includes a working target plate temperature control module and a standby target plate temperature control module;

[0015] The distribution valve box is provided with a working cold quantity outlet and a working heat regeneration inlet connected to the working target plate, and a standby cold quantity outlet and a standby working heat regeneration inlet connected to the standby target plate. The working target plate temperature control module includes a working low-temperature throttle valve, a working cold quantity output pipeline, and a working heat regeneration pipeline. The standby target plate temperature control module includes a standby low-temperature throttle valve, a standby cold quantity output pipeline, and a standby heat regeneration pipeline;

[0016] The working low-temperature throttle valve and the standby low-temperature throttle valve are connected in parallel between the second-stage precooling pipeline and the three-stage precooling pipeline near one end of the second cold quantity inlet. The two ends of the working cold quantity pipeline are respectively connected to the three-stage precooling pipeline near one end of the second cold quantity inlet and the working cold quantity outlet. The two ends of the standby cold quantity pipeline are respectively connected to the three-stage precooling pipeline near one end of the second cold quantity inlet and the standby cold quantity outlet. The two ends of the working heat regeneration pipeline are respectively connected to the three-stage precooling pipeline far from the second cold quantity inlet and the working heat regeneration inlet. The two ends of the standby heat regeneration pipeline are respectively connected to the three-stage precooling pipeline far from the second cold quantity inlet and the standby heat regeneration inlet.

[0017] Preferably, two regenerators arranged in series are provided in the cold source valve box.

[0018] Preferably, the low-temperature cold source unit further includes a normal-temperature pipeline and a low-temperature pipeline. The two ends of the low-temperature pipeline are respectively connected to the output end of the circulation pump and the high-temperature channel inlet of the regenerator. A low-temperature flow controller is provided on the low-temperature pipeline. The two ends of the normal-temperature pipeline are respectively connected to the output end of the circulation pump and the output end of the refrigerator. A normal-temperature flow controller is provided on the normal-temperature pipeline.

[0019] In the present invention, a temperature control system with variable temperature cycling in a wide temperature range for semiconductors is proposed. It adopts a regenerative closed-cycle structure design. The main pipelines of the cold source unit and the distribution unit are respectively placed in the valve box, and the inside of the valve box is evacuated to form a vacuum environment, reducing the convective heat transfer of the residual gas molecules inside the pipeline, minimizing the heat leakage of the cryogenic working fluid, and ensuring the low return gas temperature of nitrogen, thereby maximizing the cold recovery and energy-saving utilization. A throttle valve is arranged in the distribution valve box, and the temperature in the distribution valve box is effectively further reduced by means of pressure reduction, effectively expanding the application temperature range of the system. At the same time, three-stage precooling pipelines are arranged in the cold source valve box and the distribution valve box, and the cold source valve box, the distribution valve box and the throttle valve are precooled in stages at the initial stage of the system operation to ensure the low-temperature injection efficiency during the semiconductor production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. 6 is a schematic structural diagram of a first embodiment of a temperature control system with variable temperature cycling in a wide temperature range for semiconductors proposed by the present invention.

[0021] Figure 2 FIG. 10 is a schematic structural diagram of a second embodiment of a temperature control system with variable temperature cycling in a wide temperature range for semiconductors proposed by the present invention.

[0022] Figure 3 FIG. 14 is a schematic structural diagram of a third embodiment of a temperature control system with variable temperature cycling in a wide temperature range for semiconductors proposed by the present invention.

[0023] Figure 4 FIG. 18 is a schematic diagram of a low-temperature cold source unit of a third embodiment of a temperature control system with variable temperature cycling in a wide temperature range for semiconductors proposed by the present invention.

[0024] Figure 5 FIG. 22 is a schematic diagram of a low-temperature distribution unit of a third embodiment of a temperature control system with variable temperature cycling in a wide temperature range for semiconductors proposed by the present invention.

[0025] Figure 6 FIG. 26 is a schematic diagram of a low-temperature cold source unit of a fourth embodiment of a temperature control system with variable temperature cycling in a wide temperature range for semiconductors proposed by the present invention.

[0026] Figure 7 FIG. 30 is a schematic diagram of a low-temperature distribution unit of a fourth embodiment of a temperature control system with variable temperature cycling in a wide temperature range for semiconductors proposed by the present invention.

[0027] Reference Signs:

[0028] 1. Cold source valve box; 2. Refrigerator; 3. Circulation pump; 4. First vacuum pump; 5. Distribution valve box; 6. Second vacuum pump; 7. Low-temperature throttle valve; 8. Inlet heater; 9. Outlet heater; 11. Primary precooling pipeline; 12. Secondary precooling pipeline; 13. Tertiary precooling pipeline; 14. First regenerator; 15. Second regenerator; 16. First buffer tank; 17. Second buffer tank; 18. First vacuum gauge; 19. Second vacuum gauge; 20. Cold source heater; 21. Low-temperature flow controller; 22. Normal-temperature flow controller; 23. Nitrogen inlet pipeline; 24. Nitrogen outlet pipeline; 25. Filter

[0029] 100. Working target disk; 200. Precooling target disk Detailed implementation manners

[0030] Referring to Figure 1 a wide-temperature variable-temperature cycle temperature control system for semiconductor use proposed by the present invention includes: a low-temperature cold source unit and a low-temperature distribution unit

[0031] The low-temperature cold source unit includes a cold source valve box 1, a refrigerator 2, a circulation pump 3 and a first vacuum pump 4. The first vacuum pump 4 is used to evacuate the cold source valve box 1. The cold source valve box 1 is provided with a first cold quantity inlet and a first heat regeneration outlet respectively connected to the input end and the output end of the refrigerator 2. Inside the cold source valve box 1, there are a first regenerator 14, a first outlet switch valve V13 and a first inlet switch valve V14. The first outlet switch valve V13 is connected to the first cold quantity inlet. The first heat regeneration outlet is sequentially connected to the high-temperature channel of the first regenerator 14, the circulation pump 3, the low-temperature channel of the first regenerator 14 and the first inlet switch valve V14. Inside the cold source valve box 1, there is also a primary precooling pipeline 11, and both ends of the primary precooling pipeline 11 are respectively connected to the upstream pipeline and the downstream pipeline of the first outlet switch valve V13

[0032] The low-temperature distribution unit includes a distribution valve box 5 and a second vacuum pump 6. The second vacuum pump 6 is used to evacuate the distribution valve box 5. The distribution valve box 5 is provided with a cold quantity outlet and a heat regeneration inlet connected to the target disk, as well as a second cold quantity inlet and a second heat regeneration outlet connected to the cold source valve box 1. Inside the distribution valve box 5, there are a low-temperature throttle valve 7, a secondary precooling pipeline 12 and a tertiary precooling pipeline 13. The low-temperature throttle valve 7 is located on the pipeline between the cold quantity outlet and the second cold quantity inlet. Both ends of the secondary precooling pipeline 12 are respectively connected to the upstream pipeline of the low-temperature throttle valve 7 and the pipeline between the heat regeneration inlet and the second heat regeneration outlet. Both ends of the tertiary precooling pipeline 13 are respectively connected to the downstream pipeline of the low-temperature throttle valve 7 and the pipeline between the heat regeneration inlet and the second heat regeneration outlet

[0033] In the specific working process of the wide-temperature variable-temperature cycle temperature control system for semiconductors in this embodiment, under the action of the circulation pump, nitrogen gas serving as the working medium is cooled by the refrigerator and then enters the cold source valve box through the first cold quantity inlet, and enters the distribution valve box from the cold source valve box through the first outlet switch valve. In the distribution valve box, it is further cooled by being depressurized through the low-temperature throttle valve, and then flows out of the distribution valve box from the second cold quantity outlet and is provided to cool the target disk for semiconductor processing; the heated nitrogen gas returns to the distribution valve box through the second regenerative inlet, returns to the cold source valve box through the distribution valve box, and then passes through the low-temperature channel of the regenerator, the circulation pump, and the high-temperature channel of the regenerator in sequence, and then returns to the input end of the refrigerator through the first regenerative outlet to complete the closed cycle of the nitrogen gas working medium.

[0034] Since the pipelines of the entire loop are respectively arranged in the cold source valve box and the distribution valve box, in order to ensure the reliable transmission of the system's cold quantity, multi-stage precooling pipelines are provided in the system. In the specific precooling process, a first-stage low-temperature switch valve V15 is provided on the first-stage precooling pipeline 11; during the first-stage precooling process, the first outlet switch valve V13 and the first inlet switch valve V14 are closed and the first-stage low-temperature switch valve V15 is opened, and the working medium output from the output end of the refrigerator 2 sequentially passes through the first-stage precooling pipeline 11, the low-temperature channel of the first regenerator 14, the circulation pump 3, and the high-temperature channel of the first regenerator 14 and then returns to the input end of the refrigerator 2. The first-stage precooling is mainly used for the self-circulation start-up cooling of the low-temperature cold source unit. The refrigerator is started to reduce the working medium from room temperature to the lowest temperature of -150°C, and the operation of the cold source unit is monitored during the cooling process.

[0035] A second-stage low-temperature switch valve V16 is provided on the second-stage precooling pipeline 12; during the second-stage precooling process, the first-stage low-temperature switch valve V15 is closed, and the first outlet switch valve V13, the first inlet switch valve V14, and the second-stage low-temperature switch valve V16 are opened. The working medium output from the output end of the refrigerator 2 sequentially passes through the first outlet switch valve V13, the second-stage precooling pipeline 12, the first inlet switch valve V14, the low-temperature channel of the first regenerator 14, the circulation pump 3, and the high-temperature channel of the first regenerator 14 and then returns to the input end of the refrigerator 2. The second-stage precooling pipeline is mainly used for the self-circulation start-up cooling of the low-temperature cold source unit and the low-temperature distribution unit. The low-temperature cold source unit and the low-temperature distribution unit are connected by a low-temperature double-layer pipe, and the -150°C low-temperature working medium generated by starting the refrigerator is transported to the second-stage pipeline of the low-temperature distribution valve box, and the operation of the working medium is monitored during the process of being transported from the low-temperature cold source unit to the low-temperature distribution unit.

[0036] A three-stage precooling pipeline 13 is provided with a three-stage low-temperature switching valve V17. During the three-stage precooling process, the second-stage low-temperature switching valve V16 is closed, and the three-stage low-temperature switching valve V17 is opened. The working medium output from the output end of the refrigerator 2 sequentially passes through the first outlet switching valve V13, the low-temperature throttle valve 7, the three-stage precooling pipeline 13, the first inlet switching valve V14, the low-temperature channel of the first regenerator 14, the circulation pump 3, and the high-temperature channel of the first regenerator 14, and then returns to the input end of the refrigerator 2. The three-stage precooling pipeline is mainly used to regulate the opening degree of the low-temperature regulating valve to complete the throttling and cooling of the low-temperature working medium. Through the regulation of the three-stage precooling pipeline on the low-temperature throttle valve, the system temperature range is extended from the lowest temperature of -120 °C to below -160 °C. This system has a wider application temperature range. Adopting the throttling and decompression cooling technology, a low-temperature throttle valve is provided to further cool the nitrogen temperature by the decompression method.

[0037] In this embodiment, the proposed wide-temperature-range variable-temperature cycle temperature control system for semiconductors adopts a regenerative closed-cycle structure design. The main pipelines of the cold source unit and the distribution unit are respectively placed in the valve box, and the inside of the valve box is evacuated to form a vacuum environment, reducing the convective heat transfer of the residual gas molecules inside the pipeline, reducing the heat leakage of the low-temperature working medium, and ensuring the low-temperature return gas temperature of nitrogen, so as to maximize the recovery of cold quantity and energy-saving utilization; a throttle valve is arranged in the distribution valve box, and the temperature in the distribution valve box is effectively further reduced by the decompression method, effectively expanding the system application temperature range; at the same time, a three-stage precooling pipeline is arranged in the cold source valve box and the distribution valve box to perform staged precooling on the cold source valve box, the distribution valve box and the throttle valve at the initial stage of system operation, ensuring the low-temperature injection efficiency during the semiconductor production process.

[0038] During the specific regulation process of the throttle valve, the three-stage precooling pipeline 13 is provided with a three-stage low-temperature switching valve V17, and a third temperature sensor is arranged on the pipeline between the low-temperature throttle valve 7 and the three-stage low-temperature switching valve V17. By monitoring the temperature sensor downstream of the low-temperature throttle valve 7, the lowest temperature after throttling by the low-temperature throttle valve 7 is obtained, so as to ensure the decompression and cooling effect of the throttle valve.

[0039] In addition, a first temperature sensor is arranged on the pipeline between the second cold quantity inlet and the low-temperature throttle valve 7. Through the upstream temperature monitoring of the low-temperature throttle valve and the cooperation with the downstream temperature to regulate the opening degree, the decompression and cooling of the nitrogen working medium are accurately controlled.

[0040] During the semiconductor processing, usually two groups of target disks work alternately, one group as the working target disk and the other group as the standby target disk. In order to meet the cold quantity requirements of the pipelines of the two groups of target disks, referring to Figures 3 - 5 , in the specific pipeline design, the low-temperature distribution unit further includes a working target disk temperature control module and a standby target disk temperature control module;

[0041] The distribution valve box 5 is provided with a working cold quantity outlet and a working heat regeneration inlet connected to the working target disc, as well as a standby cold quantity outlet and a standby working heat regeneration inlet connected to the standby target disc. The working target disc temperature control module includes a working low-temperature throttle valve 7, a working cold quantity output pipeline, and a working heat regeneration pipeline. The standby target disc temperature control module includes a standby low-temperature throttle valve 7, a standby cold quantity output pipeline, and a standby heat regeneration pipeline;

[0042] The working low-temperature throttle valve 7 and the standby low-temperature throttle valve 7 are connected in parallel between one end of the secondary precooling pipeline 12 and the tertiary precooling pipeline 13 close to the second cold quantity inlet. The two ends of the working cold quantity pipeline are respectively connected to one end of the tertiary precooling pipeline 13 close to the second cold quantity inlet and the working cold quantity outlet. The two ends of the standby cold quantity pipeline are respectively connected to one end of the tertiary precooling pipeline 13 close to the second cold quantity inlet and the standby cold quantity outlet. The two ends of the working heat regeneration pipeline are respectively connected to one end of the tertiary precooling pipeline 13 far from the second cold quantity inlet and the working heat regeneration inlet. The two ends of the standby heat regeneration pipeline are respectively connected to one end of the tertiary precooling pipeline 13 far from the second cold quantity inlet and the standby heat regeneration inlet.

[0043] During the precooling process, the primary precooling pipeline precools the cold source valve box, and the secondary precooling pipeline precools the distribution valve box to ensure that the environment inside the valve box reaches a low-temperature environment. According to the working requirements, the tertiary precooling pipeline alternately regulates the working low-temperature throttle valve to ensure the temperature reduction effect of the low-temperature throttle valve. Through the optimized design of the tertiary precooling and the pipelines through which the nitrogen working medium in the system flows, on the one hand, it is convenient for step-by-step detection in the system and ensures the safety of the target disc. On the other hand, it minimizes the influence of pipeline switching on the temperature fluctuation of the nitrogen working medium to the greatest extent.

[0044] Furthermore, the target disk is also provided with an independent rewarming pipeline. The distribution valve box 5 is also provided with a nitrogen inlet and a nitrogen outlet. An inlet heater 8 and an outlet heater 9 are also arranged inside the distribution valve box. The working target disk temperature control module further includes a working nitrogen inlet pipeline 23 and a working nitrogen outlet pipeline 24. The two ends of the working nitrogen inlet pipeline 23 are respectively connected to the inlet heater 8 and the working cold quantity outlet. The two ends of the working nitrogen outlet pipeline 24 are respectively connected to the working heat regeneration inlet and the outlet heater 9. The standby target disk temperature control module further includes a standby nitrogen inlet pipeline 23 and a standby nitrogen outlet pipeline 24. The two ends of the standby nitrogen inlet pipeline 23 are respectively connected to the inlet heater 8 and the standby cold quantity outlet. The two ends of the standby nitrogen outlet pipeline 24 are respectively connected to the standby heat regeneration inlet and the outlet heater 9. After the target disk is cooled by the working medium, the low-temperature target disk is quickly rewarmed by normal-temperature nitrogen, greatly improving the working efficiency. Specifically, the temperature of the normal-temperature nitrogen rises rapidly after passing through the inlet heater and becomes hot nitrogen. The heated nitrogen is transported to the low-temperature target disk, and the heat of the nitrogen is used to rewarm the low-temperature target disk, enabling the rapid rewarming of the low-temperature target disk and greatly improving the working efficiency. At the same time, an outlet heater is further arranged at the outlet of the target disk to further heat the low-temperature nitrogen after heat exchange with the low-temperature target disk, preventing frosting or even icing of the pipeline after the low-temperature nitrogen is discharged.

[0045] In addition, since a single refrigeration machine in the system provides cold quantity for two target disks, in other specific embodiments of the cold source unit, two first regenerators 14 arranged in series are provided inside the cold source valve box. The two regenerators are connected in series, ensuring sufficient heat exchanger area. The two regenerators exchange heat between the low-temperature return gas medium from the low-temperature distribution unit and the external normal-temperature gas, maximizing the utilization of the cold quantity of the return gas at low temperature, realizing the recovery of cold quantity and energy conservation, enabling the working medium entering the refrigeration machine to obtain a lower temperature, better exerting the cold quantity of the refrigeration machine, making the temperature of the output circulating working medium lower, having a higher cold quantity transmission efficiency and a larger cold quantity in the same temperature zone compared with other devices.

[0046] In other specific embodiments, refer to Figure 2, the low-temperature cold source unit further includes a normal-temperature pipeline and a low-temperature pipeline. The two ends of the low-temperature pipeline are respectively connected to the output end of the circulation pump 3 and the high-temperature channel inlet of the first regenerator 14. A low-temperature flow controller 21 is provided on the low-temperature pipeline. The two ends of the normal-temperature pipeline are respectively connected to the output end of the circulation pump 3 and the output end of the refrigerator 2. A normal-temperature flow controller 22 is provided on the normal-temperature pipeline. A cold source heater 20 is provided in the cold source valve box 1, and the cold source heater 20 is arranged at the first cold quantity inlet. In the initial stage of system operation, the temperature difference between the input end and the output end of the refrigerator is relatively large, resulting in a relatively long system stabilization time. The working medium is completely heated by the cold source heater to become gaseous, and then through the normal-temperature flow controller 22 and the low-temperature flow controller 21, the gas is divided into two paths, and the two are mixed at the refrigerator outlet. Finally, through the power adjustment of the heater, the accurate control of the outlet temperature is realized. At the same time, this method can avoid the impact caused by the mixing of high- and low-temperature two-phase working media, resulting in temperature fluctuations, shorten the system stabilization time, and realize the accurate temperature control of the fluid working medium.

[0047] In actual design, the first vacuum pump and the second vacuum pump can adopt dry pumps.

[0048] The variable-temperature cycle temperature control system of this embodiment will be described in detail below through specific examples.

[0049] Refer to Figures 6 - 7 , this embodiment proposes a variable-temperature cycle temperature control system, which includes a low-temperature cold source unit and a low-temperature distribution unit. The low-temperature cold source unit and the low-temperature distribution unit are connected through a low-temperature double-layer pipe. The low-temperature cold source unit mainly provides a circulating fluid with a certain temperature and pressure for the target disk in semiconductor production and forms a closed cycle to meet the low-temperature injection conditions required by the target disk. The low-temperature distribution unit is mainly used for the distribution and transportation of the low-temperature circulation medium of the working target disk and the pre-cooled target disk in semiconductor production. The variable-temperature cycle temperature control system of the present invention can provide functions such as a wide temperature range, large refrigeration capacity, and high-precision temperature control for semiconductor production processes.

[0050] The low-temperature cold source unit includes a cold source valve box, a refrigerator, a first buffer tank 16, a circulation pump, a second buffer tank 17, a low-temperature flow controller 21, a normal-temperature flow controller 22, and a refrigerator. Inside the cold source valve box, there are a low-temperature switch valve V14, a first regenerator 14, a second regenerator 15, a cold source heater, a low-temperature switch valve V13, and a low-temperature switch valve V15. The inside of the cold source valve box is evacuated by the first vacuum pump to form a vacuum environment, which can reduce the convective heat transfer of the residual gas molecules inside, reduce the heat leakage of the low-temperature working medium, and ensure the low-temperature return gas temperature of nitrogen.

[0051] The low-temperature cold source unit and the low-temperature distribution unit are connected by a low-temperature double-layer pipe. The first regenerator 14 and the second regenerator 15 are connected in series. The inlet and outlet of the heat exchanger after series connection are respectively provided with an eighth temperature sensor, a ninth temperature sensor, a tenth temperature sensor, an eleventh temperature sensor, an eighth pressure sensor, and an eleventh pressure sensor, which are used to monitor the temperature and pressure of the working medium at the inlet and outlet of the regenerator. The outlet of the first buffer tank 16 and the inlet of the second buffer tank 17 are connected by a single-layer pipe, and a circulation pump for driving the circulation of the working medium is provided therebetween. A ninth pressure sensor is provided on the first buffer tank 16, and a tenth pressure sensor and a ninth pressure relief valve are provided on the second buffer tank 17. A low-temperature flow controller 21 is connected between the outlet of the second buffer tank 17 and the inlet of the second regenerator 15 through a single-layer pipeline, which is used to transport and regulate the low-temperature gas into the second regenerator 15 for precooling. A normal-temperature flow controller 22 is connected between the outlet of the second buffer tank 17 and the outlet of the refrigerator through a single-layer pipeline, which is used to transport and regulate the high-temperature gas into the low-temperature distribution unit.

[0052] A cold source heater is provided at the outlet of the refrigerator, which is used to mix the high-temperature gas passing through the normal-temperature flow controller 22 and the low-temperature gas passing through the low-temperature flow controller 21, and the temperature of the working medium at the outlet of the refrigerator is regulated by mixing. The outlet of the cold source heater and the inlet of the low-temperature switch valve V13 are connected by a pipeline. A first-stage low-temperature switch valve V15 is provided for the first-stage precooling closed cycle of the low-temperature cold source unit, and a twelfth temperature sensor is provided.

[0053] The cold source valve box is connected to the first vacuum pump through a pipeline, and an electromagnetic valve for controlling the start and stop of the vacuum pumping of the interlayer of the cold source valve box is provided therebetween. The first vacuum gauge 18 is connected to the outside of the cold source valve box, which is used to monitor the vacuum degree of the interlayer of the cold source valve box.

[0054] The inlet pipeline of the first buffer tank 16 is successively connected with a first check valve, a first diaphragm valve BV1, a pressure reducing valve, and a filter 25, which are used for nitrogen supplementation of the pipeline system. The inlet pipeline of the first buffer tank 16 is connected with a second diaphragm valve BV2, which is used for evacuation and replacement of the pipeline of the low-temperature cold source unit.

[0055] The low-temperature distribution unit includes a distribution valve box, a working target disk, and a precooling target disk. The distribution valve box is connected to the second vacuum pump through a pipeline, and a second electromagnetic valve for controlling the start and stop of the vacuum pumping of the interlayer of the cold source valve box is provided. The second vacuum gauge 19 is connected to the outside of the low-temperature valve box, which is used to monitor the vacuum degree of the interlayer of the distribution valve box.

[0056] The inlet of the second-stage low-temperature switch valve V16 is connected to the outlet of the low-temperature cold source unit, and its outlet is connected to the inlet of the low-temperature cold source unit, serving as the switch control of the second-stage precooling pipeline. The outlet of the low-temperature cold source unit is provided with a first temperature sensor, a first pressure sensor, and a first pressure relief valve SRV1.

[0057] The pipeline system where the working target disk 100 is located is successively connected with a first low-temperature throttle valve TV1, a low-temperature on-off valve V3, the working target disk 100, and a low-temperature on-off valve V5. The inlet of the first low-temperature throttle valve TV1 is connected to the outlet of the low-temperature cold source unit, and the outlet of the low-temperature on-off valve V5 is connected to the inlet of the low-temperature cold source unit. The low-temperature throttle valve TV1 is used to control the temperature of the working medium entering the working target disk. A seventh pressure sensor is provided at the outlet of the low-temperature on-off valve V5.

[0058] The inlet of the three-stage low-temperature on-off valve V17 is connected to the outlet of the first low-temperature throttle valve TV1, and its outlet is connected to the inlet of the low-temperature cold source unit, serving as the switch control of the three-stage precooling pipeline. A third temperature sensor, a third pressure sensor, and a third pressure relief valve SRV3 are provided at the outlet of the first low-temperature throttle valve TV1.

[0059] A fourth pressure sensor, a fourth pressure relief valve SRV4, and a low-temperature on-off valve V11 are provided in the pipeline between the inlet of the working target disk 100 and the outlet of the low-temperature on-off valve V3. A fourth pressure sensor is provided at the outlet of the working target disk.

[0060] The pipeline system where the pre-cooling target disk 200 is located is successively connected with a low-temperature throttle valve TV2, a low-temperature on-off valve V4, the pre-cooling target disk 200, and a low-temperature on-off valve V6. The inlet of the low-temperature throttle valve TV2 is connected to the outlet of the low-temperature cold source unit, and the outlet of the low-temperature on-off valve V6 is connected to the inlet of the low-temperature cold source unit. The low-temperature throttle valve TV2 is used to control the temperature of the working medium entering the pre-cooling target disk. The inlet of the low-temperature on-off valve V18 is connected to the outlet of the second low-temperature throttle valve TV2, and its outlet is connected to the inlet of the low-temperature cold source unit, serving as the switch control of the three-stage precooling pipeline. Specifically, a second temperature sensor, a second pressure sensor, and a first pressure relief valve SRV2 are provided at the outlet of the low-temperature throttle valve TV2. A fifth pressure sensor, a fifth pressure relief valve SRV5, and a low-temperature on-off valve V12 are provided in the pipeline between the inlet of the pre-cooling target disk and the outlet of the low-temperature on-off valve V4. A fifth pressure sensor is provided at the outlet of the pre-cooling target disk.

[0061] The warming pipeline system where the working target disk is located is successively connected with a second one-way valve, a third diaphragm valve, a target disk inlet heater, a low-temperature on-off valve V7, the working target disk, a low-temperature on-off valve V9, a target disk outlet heater, and a third one-way valve. A sixth pressure sensor is provided at the inlet of the target disk inlet heater, and a sixth temperature transmitter is provided at the outlet. A seventh temperature sensor is provided at the outlet of the target disk outlet heater. The warming pipeline system where the pre-cooling target disk is located is successively connected with a second one-way valve, a third diaphragm valve, a target disk inlet heater, a low-temperature on-off valve V8, the working target disk, a low-temperature on-off valve V10, a target disk outlet heater, and a third one-way valve.

[0062] The first pressure relief valves SRV1, SRV2, the third pressure relief valve SRV3, the fourth pressure relief valve SRV4, the fifth pressure relief valve SRV5, the sixth pressure relief valve SRV6, and the seventh pressure relief valve SRV7 connected to the internal pipelines of the low-temperature valve box are aggregated and then connected to the first muffler and the second muffler. The nitrogen discharge pipeline of the rewarming pipeline is also aggregated with the pressure relief valve discharge pipeline and then discharged through the second muffler.

[0063] A first solenoid valve is provided between the cold source valve box and the first vacuum pump to control the opening and closing of the suction pipeline. The cold source valve box is connected with a first vacuum gauge 18 to monitor the vacuum degree inside the interlayer of the cold source valve box. When the vacuum degree value is higher than the set value, the feedback signal is transmitted to the first solenoid valve and the first vacuum pump. According to the principle of starting the first vacuum pump first and then opening the first solenoid valve, it can prevent external air from entering the cold source valve box and causing instant frosting and dew condensation in the cold source valve box. When the vacuum degree value reaches the set value, the first solenoid valve is closed first and then the first vacuum pump is closed to maintain the internal vacuum. With the design of interlocking feedback, by measuring the pressure value in the pipeline, the automatic air replenishment function can be realized, fully achieving the highly automated operation of the system, thoroughly solving the problem of manual operation, liberating the hands of workers, and improving work efficiency.

[0064] There are two regenerators inside the cold source valve box, namely the first regenerator 14 and the second regenerator 15. The two regenerators are connected in series to ensure sufficient heat exchanger area. The two regenerators exchange heat between the low-temperature return gas medium from the low-temperature distribution unit and the external normal-temperature gas, maximizing the utilization of the cold quantity of the return gas at low temperature, realizing the recovery of cold quantity and energy conservation, enabling the working medium entering the refrigerator to obtain a lower temperature, better exerting the cold quantity of the refrigerator, making the output circulating working medium temperature lower, having a higher cold quantity transmission efficiency and a larger cold quantity in the same temperature zone compared with other equipment. The inlet of the return gas pipeline of the regenerator is provided with an eighth temperature sensor and an eighth pressure sensor to monitor the temperature and pressure of the return gas inlet; the outlet of the return gas pipeline of the regenerator is provided with a ninth temperature sensor, and the first buffer tank 16 is provided with a ninth pressure sensor to monitor the temperature of the return gas outlet; the inlet of the inlet pipeline of the regenerator is provided with a tenth temperature sensor, and the second buffer tank 17 is provided with a tenth pressure sensor to monitor the temperature and pressure of the inlet gas inlet; the outlet of the outlet pipeline of the regenerator is provided with an eleventh temperature sensor and an eleventh pressure sensor to monitor the temperature and pressure of the inlet gas outlet.

[0065] The power of the low-temperature cold source unit is provided by a circulation pump, and a scroll compressor is selected as the circulation power of the driving working medium for the circulation pump. To ensure the pressure stability of the pipeline system and reduce the pressure fluctuation of the pipeline system, a first buffer tank 16 is provided at the inlet of the circulation pump, and a second buffer tank 17 is provided at the outlet of the circulation pump. The volume of the two buffer tanks is 250L. Since the inlet of the circulation pump is at low temperature and the outlet is at high pressure after the circulation pump is started, a ninth pressure relief valve is installed on the second buffer tank to ensure that when the working medium pressure in the pipeline system is too high, it can be discharged from the pressure relief valve to avoid equipment damage and ensure the personal safety of the operators at the same time.

[0066] An automatic air replenishing device is installed in the inlet pipeline of the first buffer tank 16, which sequentially includes a filter 25, a pressure reducing valve, a first diaphragm valve BV1, and a first check valve. The function of the filter 25 is to remove the moisture in the replenished nitrogen. Since the freezing point of water is 0°C, if the moisture enters the pipeline system, it will cause the pipeline to be blocked, the flow rate to decrease or even be zero; if the moisture enters the refrigerator, the low-temperature switch valve, and the low-temperature regulating valve, it will cause damage to the refrigerator or the valve. The function of the pressure reducing valve is to control the nitrogen pressure entering the pipeline system by adjusting the handle of the pressure reducing valve to prevent the pipeline from being damaged due to excessive pressure. The first diaphragm valve BV1 is mainly used for opening and closing when nitrogen is replenished. The diaphragm valve is interlocked with the ninth pressure sensor, and the ninth pressure sensor is used to monitor the nitrogen pressure value inside the pipeline system. When the pressure value is lower than the set value, the feedback signal is transmitted to the first diaphragm valve BV1 to start the first diaphragm valve BV1 and start replenishing nitrogen into the pipeline system. When the pressure value reaches the set value, the first diaphragm valve BV1 is closed to complete the automatic replenishment of the working medium in the pipeline system. It realizes the highly automated operation of the system, completely solves the problem of manual operation, liberates the hands of the workers, and improves the work efficiency. To prevent the nitrogen inside the pipeline system from overflowing outward in the reverse direction, a first check valve is provided at the outlet of the first diaphragm valve BV1. The first check valve allows the gas to flow only from the outside to the inside and cannot flow in the reverse direction, thus ensuring the outflow of the gas inside the pipeline.

[0067] The outlet of the second buffer tank 17 is provided with two working medium output pipelines. One pipeline passes through the low-temperature flow controller 21 and enters the intake inlet of the second regenerator 15, where it exchanges heat with the low-temperature return gas, making the fluid entering the inlet of the refrigerator a low-temperature fluid. The refrigerator further cools the low-temperature fluid through the cold head and its own heat exchanger inside, so as to output a circulating working medium at a lower temperature, thereby reducing the cold loss inside the refrigerator. The other pipeline passes through the normal-temperature flow controller 22 and enters the outlet of the refrigerator. According to the value of the twelfth temperature sensor at the outlet of the refrigerator, the opening degrees of the low-temperature flow controller 21 and the normal-temperature flow controller 22 are adjusted, so as to obtain the required output working medium temperature. Considering the need to output high-temperature working medium, a cold source heater is provided at the outlet of the refrigerator. When the equipment requires a higher temperature, the cold source heater is started. The heater uses a DC power supply to output power to heat the working medium. By setting the required working medium temperature, the output power can be adaptively increased, so as to realize the output of high-temperature working medium, avoid the temperature fluctuation caused by the impact after the mixing of high-temperature and low-temperature two-phase working media, shorten the stable time of the system, and meet the precise control of the low-temperature and high-temperature continuous temperature zones.

[0068] The circulation system is provided with multiple-stage precooling pipelines, which are convenient for step-by-step detection and ensure the safety of the target disk. In order to improve production efficiency, two low-temperature injection pipelines are designed, which can simultaneously transfer cold to the working target disk and the precooled target disk. The precooled target disk is first pre-cooled. After the pre-cooling process is completed, the process continues to be transferred to the working target disk to complete the final low-temperature injection. An independent rewarming pipeline is designed for the rapid rewarming of the target disk.

[0069] First, the primary precooling is run. The working fluid circulates along the primary precooling pipeline, and the pipeline connections are in sequence: the gas return port of the first recuperator 14, the gas return port of the first recuperator 14 of the second recuperator 15, the first buffer tank 16, the circulation pump, the second buffer tank 17, the low-temperature flow controller 21, the air inlet of the second recuperator 15, the air inlet of the first recuperator 14, the refrigerator, and the low-temperature on-off valve V15. This primary precooling is mainly used for the self-circulation startup cooling of the low-temperature cold source unit. The refrigerator is started to reduce the temperature of the working fluid from room temperature to the lowest temperature of -150°C, and the operation of the cold source unit is monitored during the cooling process. After the primary precooling is completed, the low-temperature on-off valve V15 is closed, and the secondary precooling is started. The working fluid circulates along the secondary precooling pipeline, and the pipeline connections are in sequence: the low-temperature on-off valve V14, the gas return port of the first recuperator 14, the gas return port of the first recuperator 14 of the second recuperator 15, the first buffer tank 16, the circulation pump, the second buffer tank 17, the low-temperature flow controller 21, the air inlet of the second recuperator 15, the air inlet of the first recuperator 14, the refrigerator, the low-temperature on-off valve V13, and the low-temperature on-off valve V16. This secondary precooling is mainly used for the self-circulation startup cooling of the low-temperature cold source unit and the low-temperature distribution unit. The low-temperature cold source unit and the low-temperature distribution unit are connected by a low-temperature double-layer pipe. The -150°C low-temperature working fluid generated by starting the refrigerator is transported to the secondary pipeline of the low-temperature distribution valve box, and the operation of the working fluid is monitored during the process of transporting from the low-temperature cold source unit to the low-temperature distribution unit.

[0070] After the secondary precooling is completed, close the cryogenic switch valve V16 and start the tertiary precooling. The tertiary precooling is in parallel with two paths, namely the tertiary precooling of the working target disk and the tertiary precooling of the precooling target disk. The working medium of the tertiary precooling of the working target disk circulates along the tertiary precooling pipeline. The pipeline connections are in sequence: cryogenic switch valve V14, the return gas port of the first recuperator 14, the return gas port of the first recuperator 14 of the second recuperator 15, the first buffer tank 16, the circulation pump, the second buffer tank 17, the cryogenic flow controller 21, the intake port of the second recuperator 15, the intake port of the first recuperator 14, the refrigerator, the cryogenic switch valve V13, the cryogenic throttle valve TV1, and the cryogenic switch valve V17. The tertiary precooling of the working target disk is mainly used to regulate the opening of the cryogenic throttle valve TV1 to complete the throttling and cooling of the cryogenic working medium. By monitoring the third temperature sensor, the lowest temperature after throttling by the cryogenic throttle valve TV1 is obtained. The working medium of the tertiary precooling of the precooling target disk circulates along the tertiary precooling pipeline. The pipeline connections are in sequence: cryogenic switch valve V14, the return gas port of the first recuperator 14, the return gas port of the first recuperator 14 of the second recuperator 15, the first buffer tank 16, the circulation pump, the second buffer tank 17, the cryogenic flow controller 21, the intake port of the second recuperator 15, the intake port of the first recuperator 14, the refrigerator, the cryogenic switch valve V13, the cryogenic throttle valve TV2, and the cryogenic switch valve V18. The tertiary precooling of the precooling target disk is mainly used to regulate the opening of the cryogenic throttle valve TV2 to complete the throttling and cooling of the cryogenic working medium. By monitoring the second temperature sensor, the lowest temperature after throttling by the cryogenic throttle valve TV2 is obtained. The lowest temperature of domestic similar equipment can only reach -120°C. This system has a wider application temperature range and adopts the throttling and decompression cooling technology. There is a cryogenic throttle valve to reduce the nitrogen temperature below -160°C by the decompression method.

[0071] After the tertiary precooling is completed, close the cryogenic switch valve V17 and the cryogenic switch valve V18, and start the working target disk circulation system and the precooling target disk circulation system. The working medium of the working target disk circulation system circulates along the pipeline of the working target disk circulation system. The pipeline connections are in sequence: cryogenic switch valve V14, the return gas port of the first recuperator 14, the return gas port of the first recuperator 14 of the second recuperator 15, the first buffer tank 16, the circulation pump, the second buffer tank 17, the cryogenic flow controller 21, the intake port of the second recuperator 15, the intake port of the first recuperator 14, the refrigerator, the cryogenic switch valve V13, the cryogenic throttle valve TV1, the cryogenic switch valve V3, the working target disk, and the cryogenic switch valve V5. The cryogenic working medium is further throttled and cooled by the cryogenic throttle valve TV1 and then transported to the working target disk. The low-temperature working target disk is used for low-temperature injection.

[0072] The inlet of the working target disk is provided with a fourth pressure relief valve SRV4. When the working medium pressure value in the pipeline entering the cryogenic target disk exceeds a certain value and reaches the discharge pressure of the fourth pressure relief valve SRV4, the working medium is discharged from the pipeline to avoid damage to the working target disk caused by excessive pipeline pressure, thereby protecting the working target disk. At the same time, a cryogenic shut-off valve V11 is provided for evacuating and replacing the pipeline of the working target disk circulation system. The working medium of the pre-cooling target disk circulation system circulates along the pipeline of the pre-cooling target disk circulation system. The pipeline connections are successively the cryogenic shut-off valve V14, the return gas port of the first regenerator 14, the first return gas port of the second regenerator 15 and the first regenerator 14, the first buffer tank 16, the circulation pump, the second buffer tank 17, the cryogenic flow controller 21, the inlet of the second regenerator 15, the inlet of the first regenerator 14, the refrigerator, the cryogenic shut-off valve V13, the cryogenic throttle valve TV2, the cryogenic shut-off valve V4, the pre-cooling target disk, and the cryogenic shut-off valve V6. The cryogenic working medium is further throttled and cooled by the cryogenic throttle valve TV2 and then transported to the pre-cooling target disk. The cryogenic pre-cooling target disk is used for process pre-cooling. The inlet of the pre-cooling target disk is provided with a fifth pressure relief valve SRV5. When the working medium pressure value in the pipeline entering the pre-cooling target disk exceeds a certain value and reaches the discharge pressure of the fifth pressure relief valve SRV5, the working medium is discharged from the pipeline to avoid damage to the pre-cooling target disk caused by excessive pipeline pressure, thereby protecting the pre-cooling target disk. The outlet of the cryogenic distribution unit aggregate is provided with a seventh pressure relief valve SRV7 for overpressure relief protection of the return gas pipeline. At the same time, a cryogenic shut-off valve V12 is provided for evacuating and replacing the pipeline of the pre-cooling target disk circulation system.

[0073] The cryogenic distribution unit is provided with an independent target disk rewarming pipeline, including a working target disk rewarming system and a pre-cooling target disk rewarming system. The connecting pipelines of the working target disk rewarming system are successively as follows: normal temperature nitrogen passes through the second one-way valve, the third diaphragm valve, the target disk inlet heater, the cryogenic shut-off valve V7, the working target disk, the cryogenic shut-off valve V9, the target disk outlet heater, and the third one-way valve. The third diaphragm valve is used to control the opening and closing of the pipeline entering the target disk rewarming system. The third one-way valve prevents the reverse flow of nitrogen in the pipeline. At the same time, a sixth pressure relief valve SRV6 is provided for safe relief when the working target disk rewarming system is overpressurized to protect the working target disk. The target disk outlet heater can further heat the nitrogen that has become cryogenic after heat exchange with the working target disk, preventing the discharged cryogenic nitrogen from causing frosting or even icing of the pipeline and finally melting into water, which affects the operation of the equipment. A third one-way valve is provided at the outlet to prevent external air from flowing back into the target disk, resulting in damage to the target disk due to the freezing of moisture in the air. The connecting pipelines of the pre-cooling target disk rewarming system are successively as follows: normal temperature nitrogen passes through the second one-way valve, the third diaphragm valve, the target disk inlet heater, the cryogenic shut-off valve V8, the pre-cooling target disk, the cryogenic shut-off valve V10, the target disk outlet heater, and the third one-way valve.

[0074] A second electromagnetic valve is provided between the distribution valve box and the second vacuum pump to control the opening and closing of the suction pipeline. The distribution valve box is connected with a second vacuum gauge 19 to monitor the vacuum degree of the inner interlayer of the distribution valve box. When the vacuum degree value is higher than the set value, the feedback signal is transmitted to the second electromagnetic valve and the second vacuum pump. According to the principle of starting the second vacuum pump first and then opening the second electromagnetic valve, it can prevent external air from entering the low-temperature valve box, resulting in instant frosting and dew condensation in the cold source valve box. When the vacuum degree value reaches the set value, the second electromagnetic valve is closed first and then the second vacuum pump is closed to maintain the internal vacuum.

[0075] Safety relief valves are provided in all closable pipelines in the system. When the working medium pressure in the pipeline is too high during the operation of the system, it can be discharged outward from the safety relief valve to avoid equipment damage caused by too high pipeline pressure and ensure the safety of personnel at the same time. In the distribution valve box of the low-temperature distribution unit, the internal pipelines are successively connected with a first pressure relief valve SRV1, a first pressure relief valve SRV2, a third pressure relief valve SRV3, a fourth pressure relief valve SRV4, a fifth pressure relief valve SRV5, a sixth pressure relief valve SRV6, and a seventh pressure relief valve SRV7. The setting of the pressure relief valves fully solves the problem of ultra-high nitrogen pressure discharge in the segmented pipelines, effectively protects the working target disk and the pre-cooled target disk, and after being aggregated, it is connected to a first muffler and a second muffler for noise reduction treatment. At the same time, after the nitrogen returns to temperature and is discharged, it is also aggregated with the discharge pipe of the pressure relief valve and discharged through the second muffler.

[0076] This embodiment has the following advantages:

[0077] 1. The system selects nitrogen as the circulating working medium. Compared with other working media, it has the remarkable characteristics of low cost, easy availability, non-toxic, harmless, and pollution-free, and can meet the needs of long-cycle semiconductor production; the technical problem to be solved is to provide a variable-temperature cycle temperature control system with a wide temperature range, large cooling capacity, high temperature control accuracy, long service life, and simple operation, which has great significance in the field of semiconductor manufacturing. This system can be widely applied to fields such as semiconductor manufacturing and testing, is suitable for the equipment on the semiconductor production line, and can continuously provide a low-temperature medium with controllable temperature to ensure the process processing temperature required by the equipment chambers in processes such as etching, ion implantation, and diffusion in the semiconductor factory.

[0078] 2. Adopting a regenerative closed-cycle structure design can maximize the recovery of cooling capacity and energy conservation, can achieve large-flow and large-cooling-capacity transportation, has a higher cooling-capacity transportation efficiency compared with other equipment, and has a larger cooling capacity in the same temperature zone.

[0079] 3. Two methods of mixing high- and low-temperature fluids and thermal counteraction are adopted to control the output temperature of the fluid. The working medium is completely heated by the heater to become gaseous, and then through the normal-temperature flow controller 22 and the low-temperature flow controller 21, the gas is divided into two paths and mixed at the outlet of the refrigerator. Finally, through the power adjustment of the heater at the outlet, the accurate control of the outlet temperature is achieved. At the same time, this method can avoid the temperature fluctuation caused by the impact after the mixing of high- and low-temperature two-phase working media, shorten the stable time of the system, and achieve the accurate temperature control of the fluid working medium.

[0080] 4. The throttling and pressure-reducing cooling technology is adopted. There is a low-temperature throttle valve to reduce the temperature of nitrogen to below -160°C by the pressure-reducing method. The lowest temperature of the same type of equipment in China can only reach -120°C, and this system has a wider application temperature range.

[0081] 5. In the system process, there is a multi-stage precooling design for easy step-by-step detection to ensure the safety of the target disk. To improve the low-temperature injection efficiency in the semiconductor production process, two low-temperature injection pipelines are designed to simultaneously supply cold to the working target disk and the precooled target disk. The precooled target disk is first pre-cooled, and after the pre-cooling process is completed, the process continues to be transferred to the working target disk to complete the final low-temperature injection.

[0082] 6. An independent rewarming pipeline system for the target disk is designed. The temperature of the normal-temperature nitrogen gas rises rapidly after passing through the heater and becomes hot nitrogen gas. The heated nitrogen gas is transported to the low-temperature target disk, and the low-temperature target disk is rewarmed by using the heat of the nitrogen gas, which can realize the rapid rewarming of the low-temperature target disk and greatly improve the work efficiency. At the same time, an outlet heater is further set at the outlet of the target disk to further heat the low-temperature nitrogen gas after heat exchange with the low-temperature target disk to prevent frosting or even icing of the pipeline after the low-temperature nitrogen gas is discharged.

[0083] 7. All closable pipelines in the system are equipped with safety relief valves. When the pressure of the working medium in the pipeline is too high during the operation of the system, it can be discharged outward from the safety relief valve to avoid equipment damage caused by too high pipeline pressure and ensure the safety of personnel at the same time.

[0084] 8. The system adopts a chain feedback design. By measuring the pressure value in the pipeline, the automatic air replenishment function can be realized; by measuring the value of the interlayer vacuum degree, the automatic start of the pump for evacuation can be realized. This design fully realizes the highly automated operation of the system, completely solves the problem of manual operation, liberates the hands of workers, and improves work efficiency.

[0085] The above is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered by the protection scope of the present invention.

Claims

1. A wide temperature range variable temperature cycle temperature control system for semiconductors, comprising: The low temperature cold source unit and the low temperature distribution unit are characterized in that: The low-temperature distribution unit comprises a distribution valve box (5) and a second vacuum pump (6), the second vacuum pump (6) being used for evacuating the distribution valve box (5), the distribution valve box (5) being provided with a cold outlet and a heat recovery inlet connected to the target plate, and a second cold inlet and a second heat recovery outlet connected to the low-temperature cold source unit, the distribution valve box (5) being provided with a low-temperature throttle valve (7), a secondary precooling pipeline (12) and a tertiary precooling pipeline (13), the low-temperature throttle valve (7) being located on the pipeline between the cold outlet and the second cold inlet, the two ends of the secondary precooling pipeline (12) being respectively connected to the upstream pipeline of the low-temperature throttle valve (7) and the pipeline between the heat recovery inlet and the second heat recovery outlet, and the two ends of the tertiary precooling pipeline (13) being respectively connected to the downstream pipeline of the low-temperature throttle valve (7) and the pipeline between the heat recovery inlet and the second heat recovery outlet.

2. The wide temperature range variable temperature cycle temperature control system for semiconductors according to claim 1, characterized in that: The low-temperature cold source unit comprises a cold source valve box (1), a refrigerator (2), a circulating pump (3) and a first vacuum pump (4), wherein the first vacuum pump (4) is used to evacuate the cold source valve box (1), the cold source valve box (1) is provided with a first reheat outlet and a first cold inlet respectively connected to the input end and the output end of the refrigerator (2), the cold source valve box (1) is provided with a reheater, a first outlet switch valve V13 and a first inlet switch valve V14, the first outlet switch valve V13 is connected to the first cold inlet, the first reheat outlet is connected in sequence to the high-temperature channel of the reheater, the circulating pump (3), the low-temperature channel of the reheater and the first inlet switch valve V14, the cold source valve box (1) is also provided with a first-stage precooling pipeline (11), the two ends of the first-stage precooling pipeline (11) are respectively connected to the upstream pipeline of the first outlet switch valve V13 and the downstream pipeline of the first outlet switch valve V13.

3. The wide temperature range variable temperature cycle temperature control system for semiconductors according to claim 2, characterized in that: A first-stage low-temperature switch valve V15 is provided on the first-stage precooling pipeline (11); during the first-stage precooling process, the first outlet switch valve V13 and the first inlet switch valve V14 are closed and the first-stage low-temperature switch valve V15 is opened, and the working fluid output from the output end of the refrigerator (2) passes through the first-stage precooling pipeline (11), the low-temperature channel of the regenerator, the circulation pump (3), the high-temperature channel of the regenerator, and then returns to the input end of the refrigerator (2).

4. The wide temperature range variable temperature cycle temperature control system for semiconductors according to claim 3, characterized in that: A secondary low-temperature switch valve V16 is provided on the secondary precooling pipeline (12); during the secondary precooling process, the primary low-temperature switch valve V15 is closed, and the first outlet switch valve V13, the first inlet switch valve V14 and the secondary low-temperature switch valve V16 are opened, and the working fluid output from the output end of the refrigerator (2) passes through the first outlet switch valve V13, the secondary precooling pipeline (12), the first inlet switch valve V14, the low-temperature channel of the regenerator, the circulation pump (3), the high-temperature channel of the regenerator, and then returns to the input end of the refrigerator (2).

5. The wide temperature range variable temperature cycle temperature control system for semiconductors according to claim 4, characterized in that: A third-stage low-temperature switch valve V17 is provided on the third-stage precooling pipeline (13). During the third-stage precooling process, the second-stage low-temperature switch valve V16 is closed and the third-stage low-temperature switch valve V17 is opened. The working fluid output from the output end of the refrigerator (2) passes through the first outlet switch valve V13, the low-temperature throttle valve (7), the third-stage precooling pipeline (13), the first inlet switch valve V14, the low-temperature channel of the regenerator, the circulation pump (3), the high-temperature channel of the regenerator, and then returns to the input end of the refrigerator (2).

6. The semiconductor wide temperature range variable temperature cycle temperature control system according to claim 2, characterized in that: A three-stage low-temperature switch valve is provided on the three-stage precooling pipeline (13), and a third temperature sensor is provided on the pipeline between the low-temperature throttle valve (7) and the three-stage low-temperature switch valve.

7. The semiconductor wide temperature range variable temperature cycle temperature control system according to claim 2 or 6, characterized in that: A first temperature sensor is provided on the pipeline between the second cold capacity inlet and the low-temperature throttle valve (7).

8. The wide temperature range variable temperature cycle temperature control system for semiconductors according to claim 2, characterized in that: The low temperature distribution unit also includes a working target plate temperature control module and a standby target plate temperature control module; The distribution valve box (5) is provided with a working cold capacity outlet and a working heat recovery inlet connected to the working target disk, and a standby cold capacity outlet and a standby working heat recovery inlet connected to the standby target disk. The working target disk temperature control module comprises a working low temperature throttle valve (7), a working cold capacity output pipeline and a working heat recovery pipeline. The standby target disk temperature control module comprises a standby low temperature throttle valve (7), a standby cold capacity output pipeline and a standby heat recovery pipeline. The working low-temperature throttle valve (7) and the standby low-temperature throttle valve (7) are connected in parallel between the secondary precooling pipeline (12) and the tertiary precooling pipeline (13) near the second cooling capacity inlet, the two ends of the working cooling capacity pipeline are respectively connected to the end of the tertiary precooling pipeline (13) near the second cooling capacity inlet and the working cooling capacity outlet, the two ends of the standby cooling capacity pipeline are respectively connected to the end of the tertiary precooling pipeline (13) near the second cooling capacity inlet and the standby cooling capacity outlet, the two ends of the working heat recovery pipeline are respectively connected to the end of the tertiary precooling pipeline (13) away from the second cooling capacity inlet and the working heat recovery inlet, and the two ends of the standby heat recovery pipeline are respectively connected to the end of the tertiary precooling pipeline (13) away from the second cooling capacity inlet and the standby heat recovery inlet.

9. The semiconductor wide temperature range variable temperature cycle temperature control system according to claim 2 or 8, characterized in that: Two heat regenerators arranged in series are arranged in the cold source valve box.

10. The semiconductor wide temperature range variable temperature cycle temperature control system according to claim 2, characterized in that: The low-temperature cold source unit also includes a normal temperature pipeline and a low temperature pipeline, wherein two ends of the low temperature pipeline are respectively connected to the output end of the circulation pump (3) and the high temperature channel inlet of the regenerator, and a low temperature flow controller (21) is provided on the low temperature pipeline, and two ends of the normal temperature pipeline are respectively connected to the output end of the circulation pump (3) and the output end of the refrigerator (2), and a normal temperature flow controller (22) is provided on the normal temperature pipeline.

Images