Semiconductor temperature control device

Abstract

The application discloses a kind of semiconductor temperature control equipment, including liquid nitrogen supply unit, heat exchange unit and energy recovery unit, liquid nitrogen supply unit is communicated with heat exchange unit by liquid nitrogen pipeline, heat exchange unit and energy recovery unit are communicated by heat transfer fluid pipeline, liquid nitrogen supply unit includes the liquid nitrogen storage tank with liquid nitrogen outlet;Heat exchange unit includes cryogenic heat exchanger, load heat exchange end, cryogenic heat exchanger has shell and is arranged in nitrogen tube and heat transfer fluid heat exchanger in shell, heat transfer fluid heat exchanger and nitrogen tube wall heat exchange, heat transfer fluid heat exchanger is arranged in nitrogen tube, load heat exchange end is used to cool target load, the present application uses liquid nitrogen as cold source, by indirect refrigeration system cooling low temperature heat transfer fluid, then by low temperature heat transfer fluid cooling target load to realize accurate temperature control.Solved the problem of thermal shock and temperature fluctuation caused by liquid nitrogen direct cooling, can meet the extreme low temperature process demand of 3nm and below advanced process.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor manufacturing equipment, and particularly relates to an ultralow-temperature process temperature control device in 3nm and below advanced processes. BACKGROUND

[0002] With the continuous advancement of semiconductor process nodes, especially the development of 3nm and below advanced processes, higher requirements are put forward for the performance of semiconductor temperature control devices. For example, in the etching process, a wafer temperature fluctuation of ±2℃ will result in an etching rate deviation of more than 15%.

[0003] The conventional freon refrigeration device can reach a minimum temperature of-80℃, which cannot meet the process requirements at a lower temperature. The use of a cascade refrigeration device can achieve lower temperature control, but the mechanical structure is complex. In addition, the existing semiconductor temperature control device has a slow temperature control speed when dealing with etching process device load fluctuations, which prolongs the single process cycle and seriously affects the chip process efficiency.

[0004] At present, the semiconductor temperature control device generally has the following problems: liquid nitrogen direct cooling leads to a phase change expansion rate of 680:1, causing a temperature fluctuation of more than ±5℃, which easily causes wafer thermal shock damage; the daily consumption of a pure liquid nitrogen refrigeration system is high, and the operation cost accounts for more than 60% of the total owning cost of the device. These problems seriously restrict the development of the semiconductor manufacturing industry, and a new type of ultralow-temperature temperature control device is urgently needed to solve these technical problems. SUMMARY

[0005] To meet the requirements of more advanced processes, it is particularly important to develop a semiconductor special ultralow-temperature temperature control device capable of achieving-120℃ to-80℃ temperature stability. This device not only needs to solve the problems of thermal shock and temperature fluctuation caused by liquid nitrogen direct cooling, but also needs to consider the low-temperature performance and energy efficiency of the device. At the same time, how to significantly reduce the liquid nitrogen consumption and energy recovery is also a key design point of the device.

[0006] However, the existing semiconductor temperature control device cannot meet the extremely low temperature process requirements of 3nm and below advanced processes, and there are problems of thermal shock and temperature fluctuation caused by liquid nitrogen direct cooling. Therefore, in order to solve the above problems, the application provides a semiconductor special ultralow-temperature temperature control device using liquid nitrogen indirect refrigeration and a load device linkage control system and method.

[0007] In one aspect of the present application, a semiconductor special-purpose ultra-low temperature temperature control device is provided, comprising: a liquid nitrogen supply unit, a heat exchange unit and an energy recovery unit, the liquid nitrogen supply unit is communicated with the heat exchange unit through a liquid nitrogen pipeline, the heat exchange unit is communicated with the energy recovery unit through a heat transfer fluid pipeline, wherein the liquid nitrogen supply unit comprises a liquid nitrogen storage tank, the liquid nitrogen storage tank has a liquid nitrogen outlet; the heat exchange unit comprises a cryogenic heat exchanger, a load heat exchange end and a heat transfer fluid pipeline, the cryogenic heat exchanger has a shell, a nitrogen pipe and a heat transfer fluid heat exchanger, the nitrogen pipe and the heat transfer fluid heat exchanger are arranged in the shell, the heat transfer fluid heat exchanger and the nitrogen pipe wall heat exchange, the shell has a nitrogen outlet, one end of the nitrogen pipe is communicated with the liquid nitrogen outlet, the heat transfer fluid heat exchanger is arranged beside the nitrogen pipe and has a heat transfer fluid inlet and a heat transfer fluid outlet; the load heat exchange end is used for cooling the target load, one end is communicated with the heat transfer fluid outlet through the heat transfer fluid pipeline, the other end is communicated with the energy recovery unit through the heat transfer fluid pipeline; the energy recovery unit uses low-temperature nitrogen to pre-cool the heat transfer fluid, comprising a pre-cooler communicated with the nitrogen outlet through a nitrogen pipeline, one end of the pre-cooler is communicated with the heat transfer fluid inlet through the heat transfer fluid pipeline, the other end is communicated with the load heat exchange end.

[0008] In one embodiment, the nitrogen pipe is a straight pipe, one end of the straight pipe is communicated with the liquid nitrogen outlet, the other end is a free end, liquid nitrogen enters the inside of the straight pipe from the liquid nitrogen outlet, gaseous nitrogen flows out from the opening of the free end of the straight pipe and wall heat exchanges with the heat transfer fluid outside the straight pipe.

[0009] In one embodiment, the nitrogen outlet is located in the opposite direction of the free end of the nitrogen pipe.

[0010] In one embodiment, the heat transfer fluid heat exchanger is in the shape of a coil pipe, the straight pipe is arranged inside the spiral coil pipe, the nitrogen in the shell wall heat exchanges with the heat transfer fluid in the pipeline of the heat transfer fluid heat exchanger.

[0011] In one embodiment, the heat transfer fluid is alkane or fluorine fluid.

[0012] In one embodiment, the alkane includes any one of ethane, propane and isobutane, and the fluorine fluid includes carbon tetrafluoride or perfluoropropane.

[0013] In one embodiment, a double pump set is arranged on the heat transfer fluid pipeline between the heat transfer fluid heat exchanger and the load heat exchange end, wherein the main pump adopts a magnetic drive centrifugal pump, and the standby pump has a response time ≤0.5 s.

[0014] In one embodiment, the heat transfer fluid pipeline adopts 316L stainless steel, and the sealing member selects PTFE foaming material.

[0015] In one embodiment, an expansion device is provided between the target load and the heat exchanger, and the pressure above the expansion tank is adjusted by the nitrogen gas pressure.

[0016] In one embodiment, a nitrogen gas storage tank in communication with the pre-cooler is further included for controlling the pressure of the cryogenic heat exchanger and the flow of the nitrogen gas.

[0017] In one embodiment, a control unit is further included, comprising an infrared temperature sensor, a temperature-controlled programmable logic controller, a temperature-controlled human-machine interface, and a target load component, the control unit monitors the load temperature in real time through the infrared temperature sensor, and automatically adjusts the flow and pressure of the liquid nitrogen and the heat transfer fluid according to the preset temperature set value and the difference of the preset temperature, to realize accurate temperature control.

[0018] Compared with the prior art, the present application has the following beneficial effects:

[0019] 1. Liquid nitrogen is used as the ultimate cold source, and a low-temperature heat transfer fluid is cooled by an indirect refrigeration system, the low-temperature heat transfer fluid can effectively transfer the cold of the liquid nitrogen in the heat exchange system, and the target load is cooled to -120 ℃ to -80 ℃, accurate temperature control is realized, and the extremely low-temperature process requirements of 3nm and below advanced processes are met.

[0020] 2. By introducing an indirect heat exchange system, the problems of thermal shock and temperature fluctuation caused by liquid nitrogen direct cooling are effectively solved, the problems of high phase change expansion rate (up to 680:1) and large temperature fluctuation (about ±5 ℃) caused by direct contact of liquid nitrogen are avoided, wafer thermal shock damage is effectively prevented, and chip quality is improved; the heat exchanger uses a tubular free-end inter-wall heat exchanger, liquid nitrogen flows inside the tubular heat exchanger, and gaseous nitrogen after gasification flows outside the tubular heat exchanger and exchanges heat with the low-temperature heat transfer fluid.

[0021] 3. Through intelligent flow control technology and target load device linkage control system, the liquid nitrogen flow is corrected in real time, and the liquid nitrogen consumption and operating cost are reduced.

[0022] 4. An energy recovery unit is provided, the low-temperature heat transfer fluid is pre-cooled by the cold of the gaseous nitrogen, efficient use of energy is realized, and the overall energy consumption of the equipment operation is further reduced. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings obtained according to these drawings without creative labor are still within the scope of the present application.

[0024] Figure 1 is a schematic diagram of a heat exchange process;

[0025] Figure 2 The system architecture design adopts a three-stage heat transfer architecture of "liquid nitrogen cold source - low-temperature heat transfer fluid - target load". DETAILED DESCRIPTION

[0026] The preferred embodiments of the present application will be described in detail with reference to the drawings, so as to make the purpose, features and advantages of the present application more clear. It should be understood that the embodiments shown in the drawings are not a limitation on the scope of the present application, but only to illustrate the essential spirit of the technical scheme of the present application.

[0027] In the following description, for the purpose of explaining various disclosed embodiments, certain specific details are set forth in order to provide a thorough understanding of various disclosed embodiments. However, one skilled in the relevant arts will recognize that embodiments can be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail in order to avoid obscuring the description of embodiments.

[0028] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0029] In the following description, for the purpose of clarity, directional terms such as "front", "back", "left", "right", "upper", "lower", "over", "under", "above", "below", etc. are used with reference to the orientation of the drawings. However, it is to be understood that the application can assume various alternative orientations and, accordingly, such terms are not to be understood as limiting.

[0030] It should be noted that the features shown in the drawings of the present application can belong to one embodiment or to different embodiments, as long as there is no mutual conflict between these features. In order to save space, the present application can use the same drawing to explain different embodiments, that is, the same drawing of the present application can be used to embody the features in different embodiments.

[0031] As shown in Figure 1 The present application provides a semiconductor special-purpose ultra-low temperature temperature control equipment, which comprises a liquid nitrogen supply unit, a heat exchange unit, an energy recovery unit and a control unit.

[0032] The liquid nitrogen supply unit comprises an electric heater 1, a liquid nitrogen storage tank 2, a liquid nitrogen air-cooled vaporizer 3, a pressure reducing valve V101 (pressure resistance ≥1.5 MPa), a mass flow controller V1 (accuracy ±0.5% FS), a liquid nitrogen pipeline before heating 102, a gaseous nitrogen pipeline after heating 201, and a control valve V112 of the liquid nitrogen 102.

[0033] The liquid nitrogen storage tank 2 has a liquid nitrogen outlet.

[0034] The heat exchange unit comprises a cryogenic heat exchanger 6, a load heat exchange end 9, and a heat transfer fluid pipeline. The cryogenic heat exchanger 6 comprises a shell, a nitrogen pipe, and a heat transfer fluid heat exchanger. The nitrogen pipe and the heat transfer fluid heat exchanger are arranged in the shell. The nitrogen pipe and the heat transfer fluid heat exchanger exchange heat through a wall. The shell has a nitrogen outlet. One end of the nitrogen pipe is in communication with the liquid nitrogen outlet. The heat transfer fluid heat exchanger is arranged beside the nitrogen pipe and has a heat transfer fluid inlet and a heat transfer fluid outlet.

[0035] In the embodiment, the nitrogen pipe is a straight pipe. One end of the straight pipe is in communication with the liquid nitrogen outlet. The other end is a free end. The free end has the advantage of eliminating stress when the temperature changes sharply.

[0036] The liquid nitrogen enters the inside of the straight pipe from the liquid nitrogen outlet. The gaseous nitrogen after vaporization flows out of the opening of the free end of the straight pipe. The gaseous nitrogen exchanges heat with the heat transfer fluid heat exchanger through a wall outside the straight pipe. The heat transfer fluid heat exchanger is a wall heat exchanger. The heat transfer fluid heat exchanger is in the shape of a coil pipe. The straight pipe is arranged inside the spiral coil pipe. The low-temperature heat transfer fluid in the heat transfer fluid heat exchanger exchanges heat with the gaseous nitrogen after vaporization of the liquid nitrogen through a wall. This can prevent the low-temperature heat transfer fluid from being frozen by directly exchanging heat with the liquid nitrogen.

[0037] In the embodiment, the nitrogen outlet is located in the opposite direction of the free end of the nitrogen pipe. This can make the low-temperature heat transfer fluid in the heat transfer fluid heat exchanger exchange heat with the gaseous nitrogen after vaporization of the liquid nitrogen more fully.

[0038] In other embodiments, the nitrogen pipe can also be a pipeline of other shapes.

[0039] The load heat exchange end 9 is used to cool the target load. One end is in communication with the heat transfer fluid outlet through the heat transfer fluid pipeline. The other end is in communication with the energy recovery unit through the heat transfer fluid pipeline. The energy recovery unit uses low-temperature gaseous nitrogen to pre-cool the heat transfer fluid to reduce the overall energy consumption of the equipment operation. The energy recovery unit comprises a pre-cooler 7 in communication with the nitrogen outlet through the nitrogen pipeline. One end of the pre-cooler 7 is in communication with the heat transfer fluid inlet through the heat transfer fluid pipeline. The other end is in communication with the load heat exchange end 9. The gaseous nitrogen storage tank 8 is in communication with the pre-cooler 7.

[0040] A double pump set is arranged on the heat transfer fluid pipeline between the heat transfer fluid heat exchanger and the load heat exchange end 9. The main pump P101 is a magnetic drive centrifugal pump. The response time of the standby pump P102 is ≤0.5 s.

[0041] In the embodiment, the heat transfer fluid pipeline is made of 316L stainless steel, and the sealing member is made of PTFE foam material.

[0042] The heat transfer fluid in the heat transfer fluid pipeline is alkane or fluorine fluid.

[0043] Further, the alkane includes ethane, propane, and isobutane, and the fluorine fluid includes carbon tetrafluoride (R14) and perfluoropropane; further preferably, isobutane.

[0044] An expansion device is arranged between the target load and the heat exchanger, and the pressure above the expansion tank is adjusted by the nitrogen pressure. The expansion tank 5 serves to buffer the volume expansion of the fluid with drastic temperature change.

[0045] The control unit includes an infrared temperature sensor (response time ≤10 ms), a temperature control programmable logic controller, a temperature control human-machine interface, and a target load component. The control unit monitors the load temperature in real time through the infrared temperature sensor, and automatically adjusts the flow and pressure of the liquid nitrogen and the heat transfer fluid according to the preset temperature set value and the difference between the preset temperature, so as to realize accurate temperature control.

[0046] In the liquid nitrogen cryogenic heat exchanger, the low-temperature heat transfer fluid is pre-cooled by heat exchange with low-temperature nitrogen, then enters the cryogenic heat exchanger to exchange heat with the target load, and then returns to the pre-cooling heat exchanger to realize circulation. The low-temperature nitrogen comes from the cryogenic heat exchanger system, and the liquid nitrogen comes from the liquid nitrogen storage tank. The low-temperature heat transfer fluid uses alkane or fluorine fluid medium, and its use temperature is -120 ℃ to 100 ℃.

[0047] In order to realize accurate temperature control, the outlet temperature of the pre-cooling system, the outlet temperature of the cryogenic heat exchange system, and the temperature of the target load are accurately controlled. The temperature control points are linked with the liquid nitrogen flow and pressure, the heat transfer fluid flow, the target load size, etc.

[0048] The size of the target load is directly related to the consumption of liquid nitrogen. After the consumption of liquid nitrogen is determined, the flow of the low-temperature heat transfer fluid is determined, and the temperature control is the target function.

[0049] The set temperature T4 is adjusted by the pre-cooling temperature T3, the temperature T2 at the inlet of the cryogenic heat exchange system, and the temperature T1 at the outlet of the cryogenic heat exchange system. The opening of the control V-101 can adjust the liquid nitrogen flow V1 through the cryogenic heat exchanger 6, and the pressure P1 of the cryogenic heat exchanger and the flow V2 of the nitrogen are finally controlled by the pressure P2 of the nitrogen storage tank 8. When the liquid level of the expansion tank 5 is constant, the flow V3 of the low-temperature heat transfer fluid is adjusted by the circulating pump group P101 / P102, and the heat exchange efficiency of the pre-cooler 7 can be calculated after the above parameters are determined.

[0050] The pressure P1 of the liquid nitrogen storage tank 2 is controlled by heating and vaporizing part of the liquid nitrogen by the electric heater 1. Considering factors such as pressure drop, the set pressure P2 of the nitrogen storage tank is less than the pressure difference P1, and the pressure difference is equal to the pressure drop of the pipeline system.

[0051] Nominal amount of liquid nitrogen and required flow rate of cryogenic heat transfer fluid

[0052]

[0053] where q is the required cooling capacity (kW), Q HFT is the mass flow rate of the cryogenic heat transfer fluid (m 3 / s), is the density of the cryogenic heat transfer fluid (kg / m 3 ), C p is the specific heat of the cryogenic heat transfer fluid (kJ / kg-K), T in and T out are the inlet and outlet temperatures of the cryogenic heat transfer fluid (K), respectively.

[0054] The required cooling capacity q is provided by the latent heat of vaporization of liquid nitrogen, and the cooling capacity is divided into two parts, including a precooler 7 using cryogenic nitrogen to pre-cool the cryogenic heat transfer fluid, and a liquid nitrogen cryogenic heat exchanger 6.

[0055] Assuming that the cryogenic heat transfer fluid is isobutane, the basic properties of liquid nitrogen and isobutane are shown in Table 1.

[0056] Table 1 Basic properties

[0057]

[0058] To prevent the cryogenic heat transfer fluid in the cryogenic heat exchanger from freezing and causing blockage, the following measures are taken: 1) differential pressure gauge high limit alarm; 2) low limit alarm and control of the nitrogen gas flow rate V2 of the outlet temperature of the nitrogen gas.

[0059] In general, the flow rate of the cryogenic heat transfer fluid in the system is controlled to be constant, and the motor frequency converter of the circulating pump P101 / P102 is adjusted through the flow meter. The low limit alarm of the heat transfer fluid flow rate V3 is set. When the detected flow rate V3 is very small and cannot be adjusted by the motor frequency adjustment, the accident state is entered to stop the machine.

[0060] The pressure of the expansion tank is kept stable at 4.5-5 bar by a pressure regulating valve (not shown in the figure). The high and low limit indicators of the liquid level of the expansion tank C101 are set.

[0061] Gas safety valves (not shown in the figure) are respectively set at the inlet and outlet of the cryogenic heat exchanger. Liquid safety valves are set at the outlet of the circulating pump P101 / P102.

[0062] As shown in Figure 2 , the system architecture design adopts the following "liquid nitrogen cold source-cryogenic heat transfer fluid-target process load" three-stage heat transfer architecture.

[0063] Primary cooling source: liquid nitrogen is reduced to 0.8-1.2 MPa through a pressure reducing valve, and the pressure of the outlet gas nitrogen control heat exchanger is controlled, and the gas nitrogen is used for pre-cooling the heat transfer fluid;

[0064] Secondary transfer: low-temperature heat transfer fluid (such as isobutane) absorbs process heat in a closed cycle, and the flow is adjusted by a frequency conversion pump (response time ≤1 s);

[0065] Terminal temperature control: temperature sensors are arranged in the process cavity to achieve fine tuning accuracy of ±0.05 ℃.

[0066] The cryogenic heat exchanger adopts a tubular free-end partition heat exchanger, liquid nitrogen flows in the pipe, and the gasified gas nitrogen exchanges heat with the heat transfer fluid.

[0067] As shown in Figure 1 , the heat exchange process is as follows:

[0068] The cryogenic heat exchanger 6 is composed of three streams, stream one is liquid nitrogen, and the tubular heat exchanger connected to the liquid nitrogen storage tank 2, the other end of the tubular heat exchanger is a free end, the liquid nitrogen in the pipe is gasified while flowing downward, stream two is the gas nitrogen stream, the gas nitrogen flows out from the lower free end of the tubular heat exchanger and enters the pre-cooler 7 from the upper outlet along 204, and stream three is the low-temperature heat transfer fluid, which exchanges heat with the gas nitrogen in the coil heat exchanger along 304 and then flows out from 301 to the load heat exchange end 9 through the pump P101 / P102.

[0069] The flow of liquid nitrogen is controlled by the pressure difference between P1 and P2, the pressure of P1 is controlled by the pressure of the gas nitrogen in the pipe 201 after the liquid nitrogen is gasified by electric heating 1, and the pressure of P2 is controlled by the pressure of the gas nitrogen storage tank 8 after heat exchange, and the gas nitrogen is adjusted by valve V104.

[0070] The pre-cooler 7 is composed of two streams, one stream is the gas nitrogen stream 204 flowing out from the cryogenic heat exchanger 6, the temperature of which is increased to 205 after heat exchange and flows into the gas nitrogen storage tank 8, and the other stream is the low-temperature heat transfer fluid 303, which is cooled to 304 after heat exchange.

[0071] The gas nitrogen in the liquid nitrogen storage tank 2 enters the expansion tank 5 through the pipe 202 after the liquid nitrogen in the liquid nitrogen air-cooled gasifier 3, and the expansion tank 5 is used to buffer the low-temperature heat transfer fluid, which is changed to 303 after the low-temperature heat transfer fluid 302 from the load heat exchange end 9 passes through the expansion tank 5 and then enters the pre-cooler 7; the pressure P3 of the pre-cooler 7 is controlled by the gas nitrogen after the liquid nitrogen in the liquid nitrogen storage tank 2 is gasified by the liquid nitrogen air-cooled gasifier 3.

[0072] T1-T4 are temperature control points, which are adjusted by V1, V2 and V3 mass flow controllers respectively and controlled by the PLC system 4; P1, P2 and P3 are pressure sensors, , which are differential pressure sensors, and are auxiliary adjustments.

[0073] The PLC system 4 controls the valve V110 through the line 401;

[0074] The PLC system 4 detects and controls the liquid nitrogen level L101 through the line 402;

[0075] The PLC system 4 controls the valve V101 through the line 403;

[0076] The PLC system 4 controls the low-temperature heat transfer fluid temperature T1 after heat exchange through the deep cooling heat exchanger 6 through the line 404;

[0077] The PLC system 4 controls the liquid nitrogen flow V1 through the line 405;

[0078] The PLC system 4 controls the low-temperature heat transfer fluid temperature T2 before entering the deep cooling heat exchanger 6 after pre-cooling through the pre-cooler 7 through the line 406;

[0079] The PLC system 4 controls the liquid nitrogen flow V2 through the line 407;

[0080] The PLC system 4 controls the low-temperature heat transfer fluid temperature T3 after pre-cooling through the pre-cooler 7 through the line 408;

[0081] The PLC system 4 controls the heat transfer fluid flow V3 out of the deep cooling heat exchanger 6 through the line 409;

[0082] The PLC system 4 controls the valve V103 to control the flow of the pre-cooler outlet gas nitrogen 205 through the line 410;

[0083] The PLC system 4 detects and controls the pressure P2 of the gas nitrogen storage tank 8 through the valve 104 through the line 411;

[0084] The PLC system 4 detects and controls the pressure P3 through the valve 109 to control the low-temperature heat transfer fluid level L102 in the expansion tank 5 through the line 412;

[0085] The PLC system 4 controls the valve V108 through the line 413;

[0086] The PLC system 4 detects and controls the target load temperature T4 through the line 414;

[0087] The PLC system 4 controls the double pump group P101, P102 through the line 415;

[0088] The PLC system 4 controls the valve V109 through the line 416.

[0089] The liquid nitrogen and gas nitrogen system provides a cold source, and finally the gas nitrogen is stored in the gas nitrogen storage tank 8, which is a semi-closed system; the low-temperature heat transfer fluid is a closed system, and the expansion tank 5 plays a buffering role.

[0090] The block diagram of the semiconductor special ultra-low temperature temperature control equipment and load linkage control system is shown in the following figure Figure 2 .

[0091] Liquid nitrogen supply unit debugging

[0092] The liquid nitrogen storage tank pressure is pre-charged to 1.5 MPa, and the first-stage pressure reducing valve V101 is opened to reduce to a preset pressure such as 1.0 MPa. The liquid nitrogen is controlled by V1 flow into the cryogenic heat exchanger 6, and after gasification, it exchanges heat with the low-temperature heat transfer fluid.

[0093] Heat transfer fluid filling process

[0094] The system is pumped to ≤10 Pa, and before injecting the heat transfer fluid, it needs to be filtered through a 0.2 μm filter, with a water content control of ≤10 ppm;

[0095] Circulating pump commissioning: first run at 20% speed for 10 min, and then gradually increase to rated speed (3000 rpm) after checking no bubbles.

[0096] Temperature control algorithm parameter setting

[0097] Proportional coefficient (KP): 0.8-1.2; integral time (TI): 5-8 s; differential time (TD): 0.5-1.0 s;

[0098] Fuzzy control rule: when the temperature deviation is > ±0.5 ℃, start the full-load maximum power output (±15 V), and at the same time adjust the liquid nitrogen flow.

[0099] The present application solves the stability, reliability and economy problems of ultra-low temperature temperature control through the innovative "liquid nitrogen cold source-heat transfer fluid-process load" three-level architecture.

[0100] It should be noted that under ultra-low temperature conditions (such as -120 ℃), to solve the problem of large target load heat transfer area, large heat load and accurate temperature control (such as ±0.05 ℃), it is necessary to start from three core dimensions of flow field control, temperature uniformity and high-precision temperature control, combined with forced circulation, optimization design, high-precision components and other measures. In the following discussion, the present application only discusses the size of the load and the consumption of liquid nitrogen.

[0101] Example 1

[0102] The present application provides a semiconductor special ultra-low temperature temperature control equipment and load device linkage control system, which comprises a liquid nitrogen storage and supply unit, a heat transfer fluid circulation system, a load device linkage control system and a material system.

[0103] The liquid nitrogen storage and supply unit is composed of a liquid nitrogen storage tank, a multi-stage pressure reducing valve and a mass flow controller. The liquid nitrogen storage tank has a volume of 10 M 3The pressure rating is 2.5 MPa. The multi-stage pressure reducing valve is a manual pressure reducing valve, and the pressure range is 0.1-1.5 MPa. The accuracy of the mass flow controller is ±0.5% FS, and the flow range is 0.1-10 L / min.

[0104] The heat transfer fluid circulation system adopts a dual-pump group design. The main pump is a magnetic drive centrifugal pump, and the flow range is 5-50 L / min. The response time of the standby pump is 0.5 s, and the heat transfer fluid uses isobutane as the heat exchange medium.

[0105] The load device linkage control system includes an infrared temperature sensor, a temperature control programmable logic controller, a temperature control human-machine interface, and a load device. The response time of the infrared temperature sensor is 10 ms, and the measurement range is -200 ℃ to 300 ℃. The load device is composed of a heater, a flow detection switch, a temperature protection switch, a contactor, and a solid-state relay.

[0106] The material system uses 316L stainless steel piping with an inner diameter of 20 mm. The sealing element uses polytetrafluoroethylene foam material, and the low-temperature embrittlement temperature is -196 ℃. The heat exchanger includes a cryogenic heat exchanger 6 and a pre-cooler 7.

[0107] In the load device linkage control system, when the load is started, the system automatically increases the liquid nitrogen flow to 10 L / min; when the load is stopped, the system automatically reduces the liquid nitrogen flow to 5 L / min.

[0108] The condenser is a tube bundle cantilever condenser with a heat exchange area of 5 m². The expansion tank has a volume of 10 L, and the built-in nitrogen pressure is 0.5 MPa.

[0109] The control system uses a PID control algorithm based on temperature error. According to the difference between the actual temperature of the load device and the preset temperature, the flow and pressure of the refrigerant are automatically adjusted.

[0110] Table 2 - Consumption of liquid nitrogen at 80 ℃

[0111]

[0112] Table 3 - Consumption of liquid nitrogen at 120 ℃

[0113]

[0114] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application.

[0115] Therefore, the embodiments should be regarded, at least in part, as exemplary and not limiting, the scope of the application being defined by the appended claims rather than the description set out above, and therefore all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

[0116] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other presenters can develop. That is, although specific embodiments of the application can have been described herein, the scope of the application is not limited to these exact embodiments, but rather is intended to include all embodiments that are within the scope of the appended claims, as well as their equivalents. It is intended that changes can be made by those skilled in the art in departing from the above without departing from the scope of the present application.

[0117] The foregoing is considered as illustrative only of the principles of the application. Numerous modifications and changes can readily occur to those skilled in the art, which modifications are intended to be within the scope of the application. Accordingly, the scope of the application is to be interpreted only as is indicated in the appended claims.

Claims

1. A semiconductor temperature control device, characterized by, The application relates to a liquid nitrogen supply unit, a heat exchange unit and an energy recovery unit, wherein the liquid nitrogen supply unit is communicated with the heat exchange unit through a liquid nitrogen pipeline, the heat exchange unit is communicated with the energy recovery unit through a heat transfer fluid pipeline, and the liquid nitrogen supply unit comprises a liquid nitrogen storage tank. The heat exchange unit comprises a cryogenic heat exchanger, a load heat exchange end and a heat transfer fluid pipeline, the cryogenic heat exchanger has a shell, a nitrogen pipe and a heat transfer fluid heat exchanger, the nitrogen pipe and the heat transfer fluid heat exchanger are arranged in the shell, the heat transfer fluid heat exchanger is wall heat-exchanged with the nitrogen pipe, the shell has a nitrogen outlet, one end of the nitrogen pipe is communicated with the liquid nitrogen outlet, the heat transfer fluid heat exchanger is arranged beside the nitrogen pipe and has a heat transfer fluid inlet and a heat transfer fluid outlet, a pressure reducing valve is arranged on the pipeline of the nitrogen pipe and the liquid nitrogen outlet, gaseous nitrogen after the liquid nitrogen is vaporized through the pressure reducing valve flows out from the nitrogen pipe, the load heat exchange end is used for cooling a target load, one end of the load heat exchange end is communicated with the heat transfer fluid outlet through the heat transfer fluid pipeline, the other end of the load heat exchange end is communicated with the energy recovery unit through the heat transfer fluid pipeline, a pump for adjusting the flow of the heat transfer fluid is arranged on the heat transfer fluid pipeline between the heat transfer fluid heat exchanger and the load heat exchange end, and a temperature sensor is arranged in a working cavity of the load heat exchange end. The energy recovery unit utilizes gaseous nitrogen to precool the heat transfer fluid, and the energy recovery unit comprises a precooler communicated with the nitrogen outlet through a nitrogen pipeline, one end of the precooler is communicated with the heat transfer fluid inlet through the heat transfer fluid pipeline, the other end of the precooler is communicated with the load heat exchange end, the heat transfer fluid is liquid alkane or fluorine fluid, and an expansion tank for buffering the volume expansion of the heat transfer fluid is further arranged between the load heat exchange end and the cryogenic heat exchanger. The nitrogen pipe is a straight pipe, one end of the straight pipe is communicated with the liquid nitrogen outlet, the other end of the straight pipe is a free end, liquid nitrogen enters the inside of the straight pipe from the liquid nitrogen outlet, gaseous nitrogen after the liquid nitrogen is vaporized flows out from the opening of the free end of the straight pipe, and the gaseous nitrogen is wall heat-exchanged with the heat transfer fluid heat exchanger outside the straight pipe. The nitrogen outlet is located on the opposite side of the free end of the nitrogen pipe.

2. The semiconductor temperature control device of claim 1, wherein, The heat transfer fluid heat exchanger is in the shape of a coil pipe, the straight pipe is arranged inside the spiral coil pipe, and the gaseous nitrogen in the shell is wall heat-exchanged with the heat transfer fluid in the pipeline of the heat transfer fluid heat exchanger.

3. The semiconductor temperature control apparatus according to claim 2, wherein The alkane comprises any one of ethane, propane and isobutane, and the fluorine fluid comprises carbon tetrafluoride or perfluoropropane.

4. The semiconductor temperature control apparatus according to claim 2, wherein A double pump set is arranged on the heat transfer fluid pipeline between the heat transfer fluid heat exchanger and the load heat exchange end, wherein a main pump is a magnetic drive centrifugal pump, and the response time of a standby pump is less than or equal to 0.5 s.

5. The semiconductor temperature control apparatus according to claim 1, wherein The heat transfer fluid pipeline is made of 316L stainless steel, and a sealing element is made of PTFE foaming material.

6. The semiconductor temperature control apparatus according to claim 1, wherein A gaseous nitrogen storage tank communicated with the precooler is further arranged, and the gaseous nitrogen storage tank is used for controlling the pressure of the cryogenic heat exchanger and the flow of the gaseous nitrogen.

7. The semiconductor temperature control apparatus of claim 1, wherein ​ 8. The semiconductor temperature control apparatus of claim 1, wherein ​ 9. The semiconductor temperature control apparatus of claim 1, wherein It also comprises a control unit, including an infrared temperature sensor, a temperature-controlled programmable logic controller, a temperature-controlled human-machine interface and a target load component, the control unit monitors the load temperature in real time through the infrared temperature sensor, and automatically adjusts the flow and pressure of the liquid nitrogen and the heat transfer fluid according to the preset temperature setting value and the preset temperature difference, so as to realize accurate temperature control.

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