Semiconductor dry etching equipment and etching temperature control method

Abstract

The present invention proposes a semiconductor dry etching device and etching temperature control method. The etching device includes a dry etching chamber, which includes a hollow wafer heating platform for heating wafers and a liquid heating channel disposed thereon. One end of the liquid heating channel is located within the wafer heating platform, and the other end passes through the dry etching chamber and is connected to a heater. The wafer heating platform includes an inner heating zone and an outer heating zone. The inner heating zone is connected to the inner heater, and the outer heating zone is connected to the outer heater. The present invention can achieve effective control of etching temperature and uniformity.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor dry etching, and in particular relates to semiconductor dry etching equipment and an etching temperature control method. Background Art

[0002] Traditional dry etching generally refers to plasma dry etching, a technique for thin film etching using plasma. When gases exist in plasma form, they exhibit two characteristics: First, the chemical activity of the gases in the plasma is much stronger than under normal conditions. Choosing the right gas, depending on the material being etched, allows for a faster reaction with the material, achieving the desired removal. Second, an electric field can be used to guide and accelerate the plasma, imparting a certain energy. When the plasma strikes the surface of the material being etched, it dislodges atoms from the material, achieving the desired etching effect through physical energy transfer. Therefore, dry etching is the result of a balance between physical and chemical processes on the wafer surface.

[0003] Traditional plasma etching can damage the surrounding structures of the film due to the energy and bombardment of the plasma, thereby reducing the processing yield of semiconductor chips.

[0004] During low-temperature dry etching, the temperature corresponding to the etching rate and etching uniformity is crucial. Ensuring the stability and uniformity of the wafer temperature is a problem that must be solved. Summary of the Invention

[0005] The purpose of the present invention is to provide a semiconductor dry etching device and an etching temperature control method, which can achieve etching temperature stability, uniformity and etching uniformity. The technical solution adopted is as follows:

[0006] A semiconductor dry etching apparatus comprises: a dry etching chamber 5, which includes: a wafer heating platform 67 for heating a wafer, on which a liquid heating channel is provided, one end of the liquid heating channel is located within the wafer heating platform 67, and the other end passes through the dry etching chamber 5 and is connected to a heater; the wafer heating platform 67 includes an inner heating zone 67c and an outer heating zone 67d;

[0007] The inner ring heating zone 67c of the wafer heating stage is connected to the inner ring heater 75a of the wafer heating stage through a liquid heating channel;

[0008] The wafer heating platform outer ring heating zone 67d is connected to the wafer heating platform outer ring heater 75b through a liquid heating channel.

[0009] Preferably, a flow stabilizing frame and a flow stabilizing baffle are provided in the inner ring heating zone 67c of the wafer heating platform;

[0010] The flow stabilizing frame, the flow stabilizing baffle and the inner ring heating zone 67c of the wafer heating platform are integrally formed and formed on the inner wall of the inner ring heating zone 67c of the wafer heating platform;

[0011] The flow stabilizing rack is located between the medium inlet 35 of the inner ring heating channel of the wafer heating platform and the medium outlet 36 of the inner ring heating channel of the wafer heating platform;

[0012] A flow stabilizing window is provided on the flow stabilizing frame, and a flow stabilizing baffle extends into the flow stabilizing window, forming a flow stabilizing channel between the flow stabilizing baffle and the flow stabilizing window.

[0013] Preferably, a No. 1 medium diverter block 38a is provided between the flow stabilizing frame and the flow stabilizing baffle.

[0014] Preferably, a plurality of No. 2 medium flow diversion blocks 38b are provided on the inner wall of the flow stabilizing frame along the circumferential direction;

[0015] A sub-baffle is provided on the flow stabilizing baffle, and the sub-baffle is located between two adjacent No. 2 medium diverter blocks 38b.

[0016] Preferably, the inner ring heater 75a of the wafer heating stage specifically includes:

[0017] The evaporator 7519, the heating medium storage tank 7516, and the booster pump 7515 are connected in sequence;

[0018] Evaporator 7519 is used to reduce the temperature of the heating medium passing through, and includes a first input terminal, a first output terminal, a second input terminal, and a second output terminal;

[0019] The pipeline between the No. 1 input terminal and the No. 1 output terminal is used to circulate the heating medium;

[0020] The pipeline between the second input end and the second output end is used to circulate the internal medium of the second cycle;

[0021] a condenser 7528 comprising a first input, a first output, a second input, and a second output;

[0022] The pipeline between the first input end and the first output end is used to circulate the high-temperature internal medium formed after evaporation;

[0023] The pipeline between the second input end and the second output end is used for circulating the cooling medium;

[0024] The first input end of the evaporator 7519 is connected to the wafer heating platform heating medium inlet 7511 through a pipeline, and the first output end of the evaporator 7519 is connected to the heating medium storage tank 7516;

[0025] The booster pump 7515 has its output end connected to the wafer heating platform heating medium outlet 7512 through pipeline No. 1;

[0026] A first electrically controlled flow valve 7524 is provided between the second input end of the evaporator 7519 and the first input end of the condenser 7528 , and a second electrically controlled flow valve 7525 is provided between the second input end of the evaporator 7519 and the first output end of the condenser 7528 ;

[0027] The second output end of the evaporator 7519 is connected to the first input end of the condenser 7528 through the second pipeline.

[0028] Preferably, the dry etching chamber 5 further includes:

[0029] The upper cover assembly 56 is placed in the etching lower chamber 58 and includes:

[0030] Cover plate body;

[0031] The upper gas distribution plate 57 is located in the lower etching chamber 58. It is fixed to the inner wall of the lower etching chamber 58 and contacts the lower end surface of the cover plate body. A step is formed on the inner wall of the upper gas distribution plate 57. The bottom surface of the upper gas distribution plate 57 is provided with a gas outlet hole that is connected to the lower gas distribution plate 71.

[0032] The first gas uniformizing plate 60 is disposed on the step of the upper gas distribution plate 57. A first gas primary buffer zone is formed between the first gas uniformizing plate 60 and the cover plate body, and a first gas secondary buffer zone is formed between the first gas uniformizing plate 60 and the inner bottom surface of the upper gas distribution plate 57. The first gas primary buffer zone is connected to the intermediate gas inlet channel. The first gas uniformizing plate 60 has air holes that connect the first gas primary buffer zone and the first gas secondary buffer zone.

[0033] The lower gas distribution plate 71 is located in the lower etching chamber 58 and is connected to the upper gas distribution plate 57;

[0034] The second gas uniformizing plate 74 is fixed between adjacent cylinders on the lower gas distribution plate 71 and has gas holes formed thereon;

[0035] And side gas channels, the channels are connected by joints, the channels pass through the cover body and the upper gas distribution plate 57, and finally connect to the gas groove at the end of the upper gas distribution plate 57.

[0036] A semiconductor dry etching temperature control method comprises the following steps:

[0037] The low-temperature heating medium flowing back from the medium outlet 36 of the inner heating channel of the wafer heating platform in the inner heating zone 67c of the wafer heating platform flows back to the heating medium storage tank 7516. The evaporator 7519 reduces the temperature of the heating medium in the heating medium storage tank 7516 and cooperates with the storage tank heater 7517 in the heating medium storage tank 7516 to heat the heating medium.

[0038] The internal medium evaporates and absorbs heat through the evaporator 7519, thereby reducing the temperature of the heating medium passing through the evaporator 7519;

[0039] Then, the internal high-temperature medium formed by the evaporation of the internal medium flows back to the inside of the condenser 7528 for cooling.

[0040] Compared with the prior art, the advantages of the present invention are:

[0041] 1. The uniformity of etching temperature can be controlled.

[0042] Specifically: Since the etching lower cavity heater 59 is provided on the wall of the etching lower cavity 58, according to the principle of thermal radiation, the temperature of the inner circle of the wafer heating platform is lower than that of the outer circle. In order to ensure the temperature uniformity of the wafer carrier, the inner circle heating zone 67c of the inner circle wafer heating platform and the outer circle heating zone 67d of the wafer heating platform are independent heating modes; at the same time, when the circulating liquid flow rate is constant, in order to allow the circulating liquid to flow evenly along the inner circle heating zone 67c of the inner circle wafer heating platform and the outer circle heating zone 67d of the wafer heating platform, a flow stabilizing frame, a flow stabilizing baffle and a diversion block are provided to ensure that the fluid flows evenly along the preset track, and the wafer heating platform is fully heat-conducted, thereby ensuring its thermal uniformity within the fluid flow range.

[0043] 2. The stability of etching temperature can be controlled.

[0044] Specifically: The wafer heating stage 67 is provided with thermocouples on the inner and outer rings, which can directly measure and feedback the temperature of the wafer heating stage 67 in real time. Specifically:

[0045] according to Figure 8 As shown, 7512 is connected to the inlet of the wafer heating platform, and 7511 is connected to the outlet of the wafer heating platform. The temperature of the circulating fluid inside it relies on the heat provided by the heating rod 7517. In order to prevent the circulating fluid temperature from overshooting and to quickly adjust the process temperature, a circulating fluid cooling system is designed. By controlling the cooling capacity of the cooling system and the output power of the heating system, the two work together to quickly stabilize the liquid temperature at the outlet of the circulating pump 7515.

[0046] Specific control principle:

[0047] The low-pressure gaseous refrigerant is compressed by the compressor 7522 to become a high-temperature and high-pressure gas, which is then cooled by the condenser to form a low-temperature and high-pressure liquid refrigerant (the condenser mainly cools down the temperature by heat exchange with the gas medium through external cooling water). The obtained low-temperature and high-pressure liquid refrigerant passes through the automatic control valve, i.e., the No. 2 electric control flow valve 7525, and after throttling and pressure reduction, it forms a low-temperature and low-pressure gas-liquid mixture refrigerant, which enters the evaporator 7519 again. Since the pressure of the medium is relatively low at this time, it is easy to produce evaporation and heat absorption, thereby achieving the purpose of heat exchange with the circulating fluid and reducing the temperature of the circulating fluid. By adjusting the opening of the No. 2 electric control flow valve 7525, the cooling capacity of the refrigeration system can be adjusted in real time to achieve dynamic PID adjustment with the heating output power, thereby realizing precise and stable temperature control;

[0048] In addition, in order to reduce the energy consumption of the heating system of the component, a liquid spray valve, namely the No. 1 electric control flow valve 7524, is set at the outlet of the evaporator 7519. The liquid refrigerant flowing through the liquid spray valve is a high-temperature gas that has not passed through the cooler 7528. It can neutralize the temperature of the low-temperature liquid entering the evaporator, prevent the temperature of the low-pressure refrigerant entering the evaporator from being too cold, reduce the cooling capacity, and thus maintain the output power of the heating system within a lower range. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a top view of a semiconductor dry etching device;

[0050] Figure 2 is a cross-sectional view of the dry etching chamber in Example 1;

[0051] Figure 3 This is a bottom view of the upper plate of the wafer heating table in embodiment 1;

[0052] Figure 4 This is a bottom view of the upper plate of the wafer heating table in embodiment 2;

[0053] Figure 5 This is a bottom view of the upper plate of the wafer heating table in embodiment 3;

[0054] Figure 6 This is a partial enlarged view of the medium diversion block a in implementation 2;

[0055] Figure 7 A partial enlarged view of the medium diversion block b in implementation 3;

[0056] Figure 8 The control principle diagram of the inner ring heater or the outer ring heater of the wafer heating stage;

[0057] Figure 9 This is the structural diagram of the lower gas distribution plate.

[0058] Among them, 1-semiconductor dry etching equipment, 2-wafer equipment front-end module;

[0059] 3- Wafer transfer transition chamber;

[0060] 4-dry etching evaporation chamber, 5-dry etching chamber;

[0061] 6-wafer transfer platform, 7-wafer transfer robot;

[0062] 11- Etching chamber gas supply cabinet,

[0063] 42-No. 1 exhaust stop valve, 43-No. 1 molecular pump, 44-No. 1 dry pump;

[0064] 45a - No. 1 high-pressure pressure gauge, 45b - No. 1 low-pressure pressure gauge;

[0065] 51-first gas filter, 61-second gas filter;

[0066] 52 - first gas heater, 62 - second gas heater;

[0067] 53 - first gas mass flow controller, 63 - second gas mass flow controller;

[0068] 54 - first gas control valve, 64 - second gas control valve;

[0069] 55a-upper cover insulation layer, 55b-lower cavity insulation layer;

[0070] 56-upper cover assembly, 57-upper gas distribution plate, 58-etching lower chamber;

[0071] 59-Etching lower cavity heater;

[0072] 60-first gas uniformity plate;

[0073] 65-pneumatic push rod assembly;

[0074] 65a-first heating zone thermocouple, 65b-second heating zone thermocouple;

[0075] 66a-first etched wafer, 66b-second etched wafer;

[0076] 67- wafer heating platform, 67a- wafer heating platform upper plate, 67b- wafer heating platform lower plate, 67c- wafer heating platform inner ring heating zone, 67d- wafer heating platform outer ring heating zone;

[0077] 68-wafer lifting rod, 70a-second gas inlet channel;

[0078] 71-lower gas distribution plate;

[0079] 72a-the inner ring heating channel of the first wafer heating stage, 72b-the inner ring heating channel of the second wafer heating stage,

[0080] 73a-the outer ring heating channel of the first wafer heating stage, 73b-the outer ring heating channel of the second wafer heating stage;

[0081] 74-second gas uniformity plate;

[0082] 75a-inner ring heater of wafer heating stage, 75b-outer ring heater of wafer heating stage;

[0083] 33- medium inlet of the outer ring heating channel of the wafer heating platform, 34- medium outlet of the outer ring heating channel of the wafer heating platform;

[0084] 35- medium inlet of the inner ring heating channel of the wafer heating platform, 36- medium outlet of the inner ring heating channel of the wafer heating platform;

[0085] 37-wafer lifting rod channel;

[0086] 38a-No. 1 medium diverter block, 38b-No. 2 medium diverter block;

[0087] 7511-wafer heating platform heating medium inlet, 7512-wafer heating platform heating medium outlet;

[0088] 7513 - No. 1 heating medium temperature sensor, 7523 - No. 2 heating medium temperature sensor;

[0089] 7514-No. 1 pipeline pressure sensor, 7520-No. 2 pipeline pressure sensor, 7521-No. 3 pipeline pressure sensor;

[0090] 7515-No. 1 additional pump, 7522-compressor;

[0091] 7516-Heating medium storage tank;

[0092] 7517-Storage tank heating rod;

[0093] 7518-Storage tank level sensor;

[0094] 7519-evaporator;

[0095] 7524-No. 1 electronically controlled flow valve, 7525-No. 2 electronically controlled flow valve;

[0096] 7526-cooling medium outlet, 7527-cooling medium inlet, 7528-condenser. DETAILED DESCRIPTION

[0097] The semiconductor dry etching apparatus and etching temperature control method of the present invention will be described in more detail below with reference to schematic diagrams, which illustrate preferred embodiments of the present invention. It should be understood that those skilled in the art may modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as being generally known to those skilled in the art and not as limiting the present invention.

[0098] like Figures 1 and 2 , a semiconductor dry etching device, comprising:

[0099] The wafer equipment front-end module 2, the wafer transfer transition chamber 3 and the wafer transfer platform 6 are connected in sequence.

[0100] The wafer transfer robot 7 is used to transfer the wafer on the wafer transfer platform 6 to the dry etching chamber 5, transfer the wafer that has completed etching in the dry etching chamber 5 to the dry etching evaporation chamber 4, and transfer the wafer that has completed high-temperature evaporation in the dry etching evaporation chamber 4 to the wafer transfer transition chamber 3. It is set on the wafer transfer platform 6.

[0101] The dry etching evaporation chamber 4 and the dry etching chamber 5 are arranged on one side of the wafer transfer platform 6 , and their side walls are connected to the wafer transfer platform 6 .

[0102] The wafer passes through the wafer equipment front-end module 2 and the wafer transfer transition chamber 3 and enters the wafer transfer platform 6. The wafer transfer robot 7 moves the wafer into the dry etching chamber 5 in sequence. After the wafer is etched in the dry etching chamber 5, the wafer is then moved by the wafer transfer robot 7 into the dry etching evaporation chamber 4. After high-temperature evaporation in the dry etching evaporation chamber 4, the wafer transfer robot 7 moves the wafer back to the wafer transfer transition chamber 3. Finally, the atmospheric robot in the wafer equipment front-end module 2 transfers the wafer back to the wafer cassette. This completes the entire wafer processing process.

[0103] Specifically, such as Figure 1 As shown, the dry etching chamber 5 has its side wall (the side connected to the wafer transfer platform 6) open, and the wafer transfer robot 7 enters the dry etching chamber 5 through the side wall of the dry etching chamber 5.

[0104] A vacuum gate valve is provided at the open end surface of the dry etching chamber 5, and the vacuum gate valve is opened by a CDA-driven cylinder. When the vacuum gate valve is closed, the dry etching chamber 5 forms a sealed space.

[0105] The dry etching evaporation chamber 4 has its sidewall (the side connected to the wafer transfer platform 6 ) open, and the wafer transfer robot 7 enters the dry etching evaporation chamber 4 through the sidewall of the dry etching evaporation chamber 4 .

[0106] A vacuum gate valve is provided at the open end surface of the dry etching evaporation chamber 4, and the vacuum gate valve is opened by a CDA-driven cylinder. When the vacuum gate valve is closed, the dry etching evaporation chamber 4 forms a sealed space.

[0107] That is, the wafer will first be etched in the dry etching chamber 5, and then transferred to the dry etching evaporation chamber 4 through the wafer transfer robot 7 to complete high-temperature evaporation, so as to realize the evaporation and volatilization of etching by-products, and finally transferred to the wafer transfer transition chamber 3 by the wafer transfer robot 7, and finally returned to the wafer equipment front-end module 2, thus completing the entire process of the wafer.

[0108] Example 1

[0109] like Figure 2 The figure shows a cross-sectional view of the dry etching chamber 5, including:

[0110] The lower cavity 58 is etched, and the upper cover assembly 56 is set on it, which forms a sealed space with the upper cover assembly 56. The sealed space is a vacuum environment. That is, the lower cavity 58 is etched as a vacuum cavity and is placed on the hollow No. 1 support frame.

[0111] The middle air inlet channel (first gas air inlet channel) is used to introduce the first gas, which is connected to the air channel opened on the upper cover plate assembly 56; the first gas is a fluorine-containing gas, which is an etching gas.

[0112] Right now Figure 2 In the diagram, the pipes outside the equipment are all external pipes.

[0113] The wafer heating platform 67 is a hollow structure used to heat the wafer. It is set on the inner bottom surface of the etching lower cavity 58 through fasteners. A liquid heating channel is set on it. One end of the liquid heating channel is located in the wafer heating platform 67, and the other end passes through the etching lower cavity 58 and is connected to the heater.

[0114] Exhaust system No. 1, used to form a low-pressure environment in the dry etching chamber 5, which is connected to the etching lower chamber 58;

[0115] Among them, the low pressure range is 0-1Torr.

[0116] The reason for maintaining low pressure during etching is that gas etching is a chemical reaction. Low pressure increases the free path of the gas, allowing for rapid diffusion and more uniform gas distribution. Furthermore, low pressure reduces the reaction temperature, as higher temperatures can cause stress on the wafer structure. According to the ideal gas state equation, low pressure can lower the reaction temperature.

[0117] The pneumatic push rod assembly 65 is disposed in the lower etching chamber 58, with its output end located inside the wafer heating platform 67. Its output end is connected to the wafer lift rods used to support the wafer. The upper ends of the wafer lift rods 68 pass through the wafer heating platform 67. The wafer lift rods 68 are located in the wafer lift rod channel 37; the wafer lift rod channel 37 is formed in the wafer heating platform 67.

[0118] The wafer heating stage 67 includes:

[0119] The lower plate 67b of the wafer heating platform is a hollow structure; the output end of the pneumatic push rod assembly 65 is located in the hollow area.

[0120] The upper plate 67a of the wafer heating platform is connected to the lower plate 67b of the wafer heating platform by bolts, and a liquid heating channel is provided on the upper plate 67a. The liquid heating channel is connected to a pipeline through a joint, and the pipeline is connected to the heater.

[0121] One end of the liquid heating channel is located in the upper plate 67 a of the wafer heating platform, and the other end passes through the lower plate 67 b of the wafer heating platform and the etching lower cavity 58 .

[0122] like Figure 2 As shown, the pipeline connecting the heater liquid outlet includes the first wafer heating platform inner ring heating channel 72a, the second wafer heating platform inner ring heating channel 72b, the first wafer heating platform outer ring heating channel 73a, and the second wafer heating platform outer ring heating channel 73b. The pipeline connecting the heater liquid inlet and the liquid heating channel are not shown.

[0123] In this embodiment, the upper plate 67 a of the wafer heating stage is used to provide a stable and uniform temperature for the first etched wafer 66 a and the second etched wafer 66 b .

[0124] like Figure 2 As shown, in this embodiment, an inner ring heating zone 67c and an outer ring heating zone 67d of the wafer heating platform are provided on the upper plate 67a of the wafer heating platform.

[0125] The two wafer heating platform inner ring heating zones 67 c are connected to the liquid outlets of the wafer heating platform inner ring heaters 75 a .

[0126] Each wafer heating platform inner ring heating zone 67 c is provided with a wafer heating platform inner ring heating channel medium inlet 35 and a wafer heating platform inner ring heating channel medium outlet 36 .

[0127] The two wafer heating platform outer ring heating zones 67d are both connected to the liquid outlet of the wafer heating platform outer ring heater 75b.

[0128] Each wafer heating platform outer ring heating zone 67 d is provided with a wafer heating platform outer ring heating channel medium inlet 33 and a wafer heating platform outer ring heating channel medium outlet 34 .

[0129] Figure 2 In the figure, the medium outlet 36 of the inner ring heating channel of the wafer heating platform, the medium outlet 34 of the outer ring heating channel of the wafer heating platform, and the liquid inlet pipe of each heater are not shown.

[0130] at the same time, Figure 2 In the figure, only a portion of the inner ring heating zone 67 c and the outer ring heating zone 67 d of each wafer heating stage 67 is shown.

[0131] like Figure 2 As shown, in this embodiment, the dry etching chamber 5 includes two symmetrical wafer heating stages 67 on the left and right.

[0132] The distance between the inner heating zone 67 c of the wafer heating platform and the central axis of the wafer heating platform 67 is smaller than the distance between the outer heating zone 67 d of the wafer heating platform and the central axis of the wafer heating platform 67 . Figure 2 There are cartographic deviations.

[0133] The first etched wafer 66 a and the second etched wafer 66 b are respectively placed on the corresponding wafer heating stage 67 for dry etching.

[0134] Thus, the portion of the liquid heating channel on the upper plate 67a of the wafer heating stage forms an inner ring heating zone 67c of the wafer heating stage and an outer ring heating zone 67d of the wafer heating stage.

[0135] The wafer heating platform outer ring heater 75b supplies heating liquid of a certain temperature into the wafer heating platform outer ring heating zone 67d through the first wafer heating platform outer ring heating channel 73a and the second wafer heating platform outer ring heating channel 73b; the temperature is in the range of 10℃-250℃.

[0136] The wafer heating platform inner ring heater 75a supplies heating liquid of a certain temperature into the wafer heating platform inner ring heating zone 67c through the first wafer heating platform inner ring heating channel 72a and the second wafer heating platform inner ring heating channel 72b; the temperature is in the range of 10℃-250℃.

[0137] The temperature is transferred to the first etching wafer 66a and the second etching wafer 66b, so that the wafers obtain a certain amount of energy for dry etching.

[0138] Here, "the wafer obtains a certain amount of energy" refers to the heat obtained by the wafer to meet the temperature required for dry etching.

[0139] The wafer heating platform 67 is internally installed with a first heating zone thermocouple 65a and a second heating zone thermocouple 65b, which are used to measure the temperature of the inner ring heating zone 67c and the outer ring heating zone 67d of the wafer heating platform respectively. The measured temperature is fed back to the inner ring heater 75a and the outer ring heater 75b of the wafer heating platform for dynamic temperature adjustment to ensure that the wafer temperature reaches the temperature and accuracy required by the dry etching process.

[0140] The first etched wafer 66 a and the second etched wafer 66 b are moved up and down by the pneumatic push rod assembly 65 pushing the wafer lifting rod 68 , and cooperate with the wafer transfer robot 7 to complete the placement and transfer of the wafers.

[0141] Specifically, the wafer transfer robot 7 enters and exits through the sidewalls (sidewalls parallel to the paper surface) of the dry etching chamber 5 .

[0142] like Figure 2 As shown, when the wafer lifting rod 68 is in the raised state, the wafer transfer robot 7 places the wafer on the wafer lifting rod 68, and then the wafer lifting rod 68 descends to fit the corresponding wafer heating platform 67. At this time, the wafer lifting rod 68 is in the descending state as shown in the figure.

[0143] After the etching process is completed, when the wafer lifting rods 68 are in the raised state again, the wafer transfer robot 7 takes the wafer thereon and transfers it to the dry etching evaporation chamber 4 .

[0144] The upper cover assembly 56 includes:

[0145] Cover plate body;

[0146] The upper cover plate insulation 55a is provided on the outer wall of the cover plate body;

[0147] The upper gas distribution plate 57 is located in the etching lower cavity 58, and is fixed to the inner wall of the etching lower cavity 58 and contacts the lower end surface of the cover body. A step is formed on the inner wall of the upper gas distribution plate 57; Figure 2 As shown, air holes are formed on the bottom surface of the upper gas distribution plate 57, and the air holes are connected to the air holes on the lower gas distribution plate 71. Specifically, air holes are formed on the cylinder on the lower gas distribution plate 71, and the cylinder abuts against the upper gas distribution plate 57.

[0148] Thus, the first gas and the second gas are not mixed before entering the etching lower chamber 58 .

[0149] In addition, since the first gas is used for etching and is introduced during the etching process, and the second gas is a purge gas and is introduced after etching, the two gases are not introduced into the etching lower chamber 58 at the same time.

[0150] Therefore, the first gas and the second gas are also not mixed after entering the lower etching chamber 58 .

[0151] The first gas uniformizing plate 60 is provided on the step of the upper gas distribution plate 57 (such as Figure 3 As shown in the figure, a first gas primary buffer zone is formed between it and the cover plate body, a first gas secondary buffer zone is formed between it and the inner bottom surface of the upper gas distribution plate 57, and the first gas primary buffer zone is connected to the middle air inlet channel; the first gas uniforming plate 60 is provided with air holes connecting the first gas primary buffer zone and the first gas secondary buffer zone.

[0152] like Figure 4 、 Figure 9 As shown, the lower gas distribution plate 71 is located in the etching lower chamber 58 and does not contact the inner wall of the etching lower chamber 58. It is fixed to the upper gas distribution plate 57 by bolts. A plurality of cylinders are provided on the lower gas distribution plate 71. The bottom surface of the lower gas distribution plate 71 is provided with air holes.

[0153] The second gas uniforming plate 74 is clamped between adjacent cylinders and has air holes formed thereon.

[0154] There is a sealing ring between the upper gas distribution plate 57 and the etching lower cavity 58 for sealing. The upper gas distribution plate 57 is placed in the etching lower cavity 58 through vacuum adsorption.

[0155] During actual assembly, the upper cover plate insulation 55a, the cover plate body, the first gas uniformizing plate 60, the upper gas distribution plate 57, and the lower gas distribution plate 71 are integrated, all connected by bolts and sealed by a sealing ring.

[0156] Specifically, the first gas is controlled by the etching chamber gas supply cabinet 11 so that the first gas enters the upper cover plate assembly 56 according to design requirements.

[0157] The first gas enters the first gas primary buffer zone through the middle gas inlet channel, and then enters the first gas secondary buffer zone through the first gas uniformizing plate 60. The first gas primary buffer zone is composed of the cover plate body and the first gas uniformizing plate 60.

[0158] The first gas uniformizing plate 60 is designed with a large number of small holes to allow the first gas to evenly enter the first gas secondary buffer zone. The number of small holes is in the range of 10-1000, and the size of the small holes is in the range of 0.5mm-10mm. The specific number and size can be adjusted according to the process results.

[0159] The first gas secondary buffer zone is composed of a first gas uniformizing plate 60 and an upper gas distribution plate 57 .

[0160] like Figure 2 As shown, a certain number and size of small holes are distributed on the upper gas distribution plate 57. The number of the small holes is in the range of 10-1000, and the size of the small holes is in the range of 0.5mm-10mm.

[0161] The first gas enters the dry etching area through the holes on the upper gas distribution plate 57 and the holes on the cylinder of the lower gas distribution plate 71 to perform the process.

[0162] like Figure 9 , which is a three-dimensional view of the lower gas distribution plate 71 .

[0163] Furthermore, the second gas is controlled by the etching chamber gas supply cabinet 11 so that the second gas enters the upper cover plate assembly 56 according to the design requirements. The second gas is an inert gas, that is, a purge gas.

[0164] like Figure 9 As shown, the etching gas (first gas) and the purge gas (second gas) do not come into contact. The reasons are:

[0165] When the wafer needs to be etched, only Figure 9 The holes on the cylinder shown in the figure flow out, and after the wafer etching reaction, it is necessary to purge the Figure 9 The purge gas holes shown flow out, blowing out the participating gases on the wafer surface and in the cavity. Since the two flow holes are equally spaced and staggered and evenly distributed, the etching uniformity is ensured.

[0166] The side gas channel (second gas inlet channel 70a) is connected to the channel through a joint. The channel passes through the upper cover insulation 55a, the cover body and the upper gas distribution plate 57, and finally connects to the gas groove at the end of the upper gas distribution plate 57.

[0167] The flow direction of the second gas is as follows: after the second gas enters the lower gas distribution plate 71, it will diffuse horizontally to the gap between adjacent cylinders and enter the upper space of the second gas uniformizing plate 74. There will be several small holes on the second gas uniformizing plate 74. The second gas enters through the small holes and fills the space formed between the lower gas distribution plate 71 and the second gas uniformizing plate 74, realizing the first gas uniform distribution; then it enters the interior of the etching lower cavity 58 through the small holes at the bottom of the lower gas distribution plate 71, realizing the second gas uniform distribution.

[0168] The etching chamber gas supply cabinet 11 includes a first gas control valve 54 , a first gas mass flow controller 53 , a first gas heater 52 , and a first gas filter 51 , which are sequentially connected to the intermediate gas channel.

[0169] The etching chamber gas supply cabinet 11 includes a second gas control valve 64 , a second gas mass flow controller 63 , a second gas heater 62 and a second gas filter 61 which are sequentially connected to the side gas channel.

[0170] A lower cavity insulation layer 55 b is further provided, which is located on the outer wall of the etched lower cavity 58 .

[0171] Exhaust system number one includes:

[0172] The No. 1 exhaust stop valve 42, the No. 1 molecular pump 43 and the No. 1 dry pump 44 are connected in sequence.

[0173] The No. 1 exhaust stop valve 42 is connected to the etching lower cavity 58 through a pipeline.

[0174] A high-pressure pressure gauge 45a and a low-pressure pressure gauge 45b are installed on the etching lower chamber 58; the high-pressure pressure gauge 45a has a full scale of 1000 Torr and is used to measure atmospheric pressure; the low-pressure pressure gauge 45b has a full scale of 10 Torr and is used to measure process pressure.

[0175] Specifically, the installation method of the No. 1 high-pressure pressure gauge 45a and the No. 1 low-pressure pressure gauge 45b is as follows:

[0176] A sealing plate is installed on the etching lower cavity 58, and a sealing ring is provided between the sealing plate and the etching lower cavity 58 for sealing. A pressure pipe connected to the interior of the etching lower cavity 58 is provided on the sealing plate, and the pipe size is between 12.7-25mm; a vacuum sealing joint and a low-pressure pressure gauge 45b are provided on the pipe.

[0177] A lower etching chamber heater 59 is further installed on the lower etching chamber 58 to ensure that the inner wall of the lower etching chamber 58 can reach a certain temperature within the range of 50°C-100°C to prevent process by-products from adhering to the inner wall of the chamber and becoming a source of particle contaminants during wafer production.

[0178] The working principle of the dry etching chamber 5 is as follows:

[0179] Step 1: The wafer transfer robot 7 transfers the etched wafer to the wafer lifting rod 68, and the wafer lifting rod 68 descends to the upper plate 67a of the wafer heating table 67;

[0180] Step 2: The etching wafer is heated to the etching reaction temperature under the action of the wafer heating stage, and the first gas in the etching lower chamber 58 reacts with the etching wafer;

[0181] The first exhaust system exhausts gas in real time to maintain the gas pressure in the etching lower chamber 58 .

[0182] like Figure 3 As shown, regarding one of the wafer heating stages 67:

[0183] The heating medium at a certain temperature flows into the inner heating zone 67c and the outer heating zone 67d of the wafer heating stage through the outer heating channel medium inlet 33 and the outer heating channel medium inlet 35 of the wafer heating stage;

[0184] Then it flows inside along the direction of the dotted arrow, flows out through the wafer heating platform outer ring heating channel medium outlet 34 and the wafer heating platform inner ring heating channel medium outlet 36 and returns to the wafer heating platform inner ring heater 75a and the wafer heating platform outer ring heater 75b.

[0185] Three wafer lifting rod channels 37 are evenly distributed on the wafer heating platform 67 , and the wafer lifting rods 68 are used to lift the first etched wafer 66 a and the second etched wafer 66 b through the wafer lifting rod channels 37 .

[0186] The control principles of the wafer heating stage inner ring heater 75a and the wafer heating stage outer ring heater 75b are the same. The control principle of the wafer heating stage inner ring heater 75a is specifically described below:

[0187] The wafer heating platform heating medium inlet 7511 is connected to the first wafer heating platform inner circle heating channel 72a, and the wafer heating platform heating medium outlet 7512 is connected to the second wafer heating platform inner circle heating channel 72b.

[0188] The wafer heating platform heating medium outlet 7512 delivers the heating medium at a certain temperature into the inner ring heating zone 67c of the wafer heating platform.

[0189] The inner ring heater 75a of the wafer heating stage includes two cycles: a first cycle III and a second cycle IV.

[0190] In the first cycle III, the heating medium is fed into the inner heating zone 67c of the wafer heating stage 67 for wafer temperature control;

[0191] Second Loop IV is used for external circulation, its purpose is to assist in the temperature control of the heating medium in First Loop III. Specifically: After the heating medium in First Loop III passes through the wafer heating table, the chemical reaction in the cavity will release heat. This heat will be transferred to the heating medium in First Loop III, thereby increasing the temperature of the heating medium in First Loop III. If the high-temperature heating medium in First Loop III directly flows back into the heating medium storage tank 7516, then the heating medium in First Loop III will be directly circulated back into the wafer heating table. In this way, the temperature will gradually accumulate, gradually increasing the wafer temperature and affecting the process. The purpose of evaporator 7519 is to cool the high-temperature heating medium in First Loop III to a temperature lower than or equal to the temperature of the medium inside heating medium storage tank 7516; then, the heater in heating medium storage tank 7516 will quickly heat up, raising the temperature of the reflux heating medium, making the process medium temperature quickly controllable.

[0192] The inner ring heater 75a of the wafer heating stage specifically includes:

[0193] The evaporator 7519, the heating medium storage tank 7516, and the booster pump 7515 are connected in sequence;

[0194] Evaporator 7519 is used to reduce the temperature of the heating medium passing through, and includes a first input terminal, a first output terminal, a second input terminal, and a second output terminal;

[0195] The pipeline between the No. 1 input terminal and the No. 1 output terminal is used to circulate the heating medium;

[0196] The pipeline between the second input end and the second output end is used to circulate the internal medium of the second cycle;

[0197] Condenser 7528, used to reduce the internal medium temperature in the second cycle IV, including a first input end, a first output end, a second input end, and a second output end;

[0198] The pipeline between the first input end and the first output end is used to circulate the high-temperature internal medium formed after evaporation;

[0199] The pipeline between the second input end and the second output end is used to circulate the cooling medium; the second input end is connected to the cooling medium inlet 7527, and the second output end is connected to the cooling medium outlet 7526.

[0200] The first input end of the evaporator 7519 is connected to the wafer heating platform heating medium inlet 7511 through a pipeline, and the first output end of the evaporator 7519 is connected to the heating medium storage tank 7516;

[0201] Booster pump 7515 is used to provide circulation pressure, and its output end is connected to the wafer heating platform heating medium outlet 7512 through pipeline No. 1;

[0202] A first electrically controlled flow valve 7524 is provided between the second input end of the evaporator 7519 and the first input end of the condenser 7528 , and a second electrically controlled flow valve 7525 is provided between the second input end of the evaporator 7519 and the first output end of the condenser 7528 ;

[0203] The second output end of the evaporator 7519 is connected to the first input end of the condenser 7528 through the second pipeline.

[0204] A No. 1 heating medium temperature sensor 7513 and a No. 1 pipeline pressure sensor 7514 are provided on the No. 1 pipeline.

[0205] The No. 1 heating medium temperature sensor 7513 is used to measure the temperature of the heating medium in the circulation; the No. 1 pipeline pressure sensor 7514 is used to measure the pressure of the heating medium.

[0206] The No. 2 pipeline is provided with a No. 2 pipeline pressure sensor 7520, a No. 3 pipeline pressure sensor 7521, a compressor 7522, and a No. 2 heating medium temperature sensor 7523.

[0207] The No. 2 pipeline pressure sensor 7520 is used to measure the pressure at the front end of the compressor 7522 in the second cycle; the No. 3 pipeline pressure sensor 7521 is used to measure the pressure at the rear end of the compressor 7522 in the second cycle; the two pressures are used to monitor whether the compressor 7522 is operating normally and whether the pressure IV in the second cycle is normal.

[0208] The second heating medium temperature sensor 7523 measures the fluid pressure in the second cycle IV;

[0209] The heating medium storage tank 7516 has a storage tank heater 7517 and a storage tank liquid level sensor 7518 inside.

[0210] Among them, the No. 1 electrically controlled flow valve 7524 and the No. 2 electrically controlled flow valve 7525 are used to control the on and off of the second cycle IV.

[0211] Working principle of the first cycle III:

[0212] The low-temperature heating medium flowing back from the medium outlet 36 of the inner ring heating channel of the wafer heating platform in the inner ring heating zone 67c of the wafer heating platform will flow back to the heating medium storage tank 7516, and the evaporator 7519 will reduce the temperature of the heating medium in the heating medium storage tank 7516; and cooperate with the storage tank heater 7517 in the heating medium storage tank 7516 to heat the heating medium; the combination of the two makes it possible to control and stabilize the temperature of the heating medium entering the wafer heating platform 67.

[0213] The second cycle IV is a closed-loop system.

[0214] Working principle of the second cycle IV:

[0215] The internal medium evaporates through evaporator 7519, absorbing heat and lowering the temperature of the heating medium in first cycle III of evaporator 7519. Any phase change process is accompanied by heat absorption and release. The lower the pressure, the lower the saturation temperature (boiling point) of the liquid medium, and the less energy is required for liquid molecules to transform into a gas. Therefore, at low pressure, the refrigerant more easily absorbs heat from the surrounding environment (such as the air or the surface of an object) to complete the phase change. At this time, the refrigerant's saturation temperature is much lower than the ambient temperature of evaporator 7519, prompting the refrigerant to continue evaporating, absorbing heat from the environment and achieving the cooling effect.

[0216] Then the internal high-temperature medium formed by the evaporation of the internal medium flows back to the inside of the condenser 7528. The cooling medium entering the inside of the condenser 7528 through the cooling medium inlet 7527 cools the high-temperature medium flowing back in the second cycle IV, reducing the medium temperature; and then circulates again.

[0217] Among them, the No. 1 electric control flow valve 7524 and the No. 2 electric control flow valve 7525 are used to control the on-off of the second cycle IV. The specific scheme is as follows:

[0218] (1) When the No. 1 electric control flow valve 7524 and the No. 2 electric control flow valve 7525 are both closed, no internal medium flows into the evaporator 7519, and the second circulation IV is disconnected.

[0219] (2) When the No. 1 electric control flow valve 7524 is closed and the No. 2 electric control flow valve 7525 is opened, the low-temperature internal medium flows into the evaporator 7519.

[0220] (3) When the No. 1 electric control flow valve 7524 and the No. 2 electric control flow valve 7525 are both open, the second cycle IV is opened.

[0221] Among them, the evaporator 7519 is used to reduce the temperature of the heating medium passing through it. The reason is: the dynamic balance between the heating rod 7517 in the storage tank and the cooling of the evaporator 7519 meets the rapid temperature change function of the semiconductor equipment, and the temperature control is more precise (±0.05℃).

[0222] like Figure 3 A flow stabilizing rack and a flow stabilizing baffle are added to the inner ring heating zone 67c of the wafer heating platform.

[0223] The flow stabilizing frame, the flow stabilizing baffle and the inner ring heating zone 67c of the wafer heating platform are integrally formed and formed on the inner wall of the inner ring heating zone 67c of the wafer heating platform;

[0224] The flow stabilizing rack is located between the medium inlet 35 and the medium outlet 36 of the inner ring heating channel of the wafer heating platform.

[0225] A flow stabilizing window is provided on the flow stabilizing frame, and a flow stabilizing baffle extends into the flow stabilizing window, forming a flow stabilizing channel between the flow stabilizing baffle and the flow stabilizing window.

[0226] Example 2

[0227] like Figure 4 、 Figure 6 As shown, a No. 1 medium flow diversion block 38a is provided between the flow stabilizing frame and the flow stabilizing baffle.

[0228] Specifically, one end of the No. 1 medium flow diversion block 38a is fixed to the inner wall of the flow stabilizing frame, and the other end is fixed to the flow stabilizing baffle.

[0229] The first medium diverter block 38a has a plurality of diverter windows formed thereon.

[0230] In order to ensure uniform wafer temperature, the heating medium needs to flow evenly and without dead angles inside the inner heating zone 67c of the wafer heating table.

[0231] A medium diversion block 38a is designed inside the inner ring heating zone 67c of the wafer heating platform. The medium diversion block 38a can force the heating medium to be diverted and pass through the heating zone evenly.

[0232] Figure 6 for Figure 4 In the enlarged view I, the heating medium can be forced to be diverted by the medium diversion block 38a, ensuring uniform flow of the heating medium in the flow channel, thereby ensuring uniform temperature of the heating stage, and ultimately achieving controllable and consistent wafer etching rate.

[0233] The outer ring heating zone 67d of the wafer heating platform, the inner ring heating channel 72a of the first wafer heating platform, the inner ring heating channel 72b of the second wafer heating platform, the outer ring heating channel 73a of the first wafer heating platform, and the outer ring heating channel 73b of the first wafer heating platform can all be equipped with corresponding medium diversion block designs to improve the temperature uniformity of the wafer heating platform 67.

[0234] Example 3

[0235] like Figure 5 、 Figure 7 As shown, a plurality of No. 2 medium flow diversion blocks 38b are provided along the circumferential direction on the inner wall of the flow stabilizing frame.

[0236] A sub-baffle is added to the flow stabilizing baffle, and the sub-baffle is located between two adjacent No. 2 medium diverter blocks 38b.

[0237] The medium diversion block 38b is distributed in the circumferential direction, which can force the heating medium to follow the Figure 5 A magnified view of the Figure 7 As shown, the flow is divided in the direction of the arrows and evenly passes through the heating zone. This ensures that the heating medium in the flow channel flows evenly, thereby ensuring a uniform temperature on the heating stage, ultimately achieving a controllable and consistent wafer etching rate.

[0238] The outer ring heating zone 67d of the wafer heating platform, the inner ring heating channel 72a of the first wafer heating platform, the inner ring heating channel 72b of the second wafer heating platform, the outer ring heating channel 73a of the first wafer heating platform, and the outer ring heating channel 73b of the first wafer heating platform can all be equipped with a corresponding medium diversion block 3 design to improve the temperature uniformity of the wafer heating platform 67.

[0239] The above description is merely a preferred embodiment of the present invention and does not limit the present invention in any way. Any person skilled in the art who, without departing from the scope of the present invention, makes any equivalent substitution, modification, or other changes to the technical solution and technical content disclosed in the present invention shall be deemed to be within the scope of the present invention and still fall within the scope of protection of the present invention.

Claims

1. A semiconductor dry etching device, characterized in that: include: A dry etching chamber (5) comprising: a wafer heating platform (67) for heating a wafer, a liquid heating channel being provided on the wafer heating platform, one end of the liquid heating channel being located within the wafer heating platform (67), and the other end of the liquid heating channel passing through the dry etching chamber (5) and connected to a heater; the wafer heating platform (67) comprising an inner heating zone (67c) of the wafer heating platform and an outer heating zone (67d) of the wafer heating platform; The inner ring heating zone (67c) of the wafer heating platform is connected to the inner ring heater (75a) of the wafer heating platform via a liquid heating channel; The outer ring heating zone (67d) of the wafer heating platform is connected to the outer ring heater (75b) of the wafer heating platform via a liquid heating channel; A flow stabilizing frame and a flow stabilizing baffle are provided in the inner ring heating zone (67c) of the wafer heating platform; The flow stabilizing frame, the flow stabilizing baffle and the inner ring heating zone (67c) of the wafer heating platform are integrally formed and formed on the inner wall of the inner ring heating zone (67c) of the wafer heating platform; The flow stabilizing frame is located between the medium inlet (35) of the inner ring heating channel of the wafer heating platform and the medium outlet (36) of the inner ring heating channel of the wafer heating platform; A flow stabilizing window is provided on the flow stabilizing frame, and a flow stabilizing baffle extends into the flow stabilizing window, forming a flow stabilizing channel between the flow stabilizing baffle and the flow stabilizing window; The inner ring heater (75a) of the wafer heating platform specifically comprises: The evaporator (7519), the heating medium storage tank (7516), and the booster pump (7515) are connected in sequence; An evaporator (7519), used for reducing the temperature of the heating medium passing therethrough, comprising a first input terminal, a first output terminal, a second input terminal, and a second output terminal; The pipeline between the No. 1 input terminal and the No. 1 output terminal is used to circulate the heating medium; The pipeline between the second input end and the second output end is used to circulate the internal medium of the second cycle; a condenser (7528) comprising a first input end, a first output end, a second input end, and a second output end; The pipeline between the first input end and the first output end is used to circulate the high-temperature internal medium formed after evaporation; The pipeline between the second input end and the second output end is used for circulating the cooling medium; The first input end of the evaporator (7519) is connected to the wafer heating platform heating medium inlet (7511) through a pipeline, and the first output end of the evaporator (7519) is connected to the heating medium storage tank (7516); A booster pump (7515), the output end of which is connected to the heating medium outlet (7512) of the wafer heating table via a No. 1 pipeline; A first electrically controlled flow valve (7524) is provided between the second input end of the evaporator (7519) and the first input end of the condenser (7528), and a second electrically controlled flow valve (7525) is provided between the second input end of the evaporator (7519) and the first output end of the condenser (7528); The second output end of the evaporator (7519) is connected to the first input end of the condenser (7528) through the second pipeline.

2. The semiconductor dry etching equipment according to claim 1, characterized in that: A No. 1 medium flow diversion block (38a) is provided between the flow stabilizing frame and the flow stabilizing baffle.

3. The semiconductor dry etching equipment according to claim 1, characterized in that: A plurality of No. 2 medium flow diversion blocks (38b) are provided on the inner wall of the flow stabilizing frame along the circumferential direction; A sub-baffle is provided on the flow stabilizing baffle, and the sub-baffle is located between two adjacent No. 2 medium flow diversion blocks (38b).

4. The semiconductor dry etching equipment according to claim 1, characterized in that: The dry etching chamber (5) further comprises: The upper cover plate assembly (56) is placed in the etching lower cavity (58), and includes: Cover plate body; An upper gas distribution plate (57) is located in the etching lower cavity (58), is clamped to the inner wall of the etching lower cavity (58), and contacts the lower end surface of the cover plate body, and a step is formed on the inner wall of the upper gas distribution plate (57); an air outlet is provided on the bottom surface of the upper gas distribution plate (57) and is connected to the lower gas distribution plate (71); A first gas uniformizing plate (60) is provided on the step of the upper gas distribution plate (57), and a first gas primary buffer zone is formed between the first gas uniformizing plate (60) and the cover plate body, and a first gas secondary buffer zone is formed between the first gas uniformizing plate (60) and the inner bottom surface of the upper gas distribution plate (57), wherein the first gas primary buffer zone is connected to the middle gas inlet channel; an air hole is provided on the first gas uniformizing plate (60) to connect the first gas primary buffer zone and the first gas secondary buffer zone; A lower gas distribution plate (71) is located in the lower etching chamber (58) and is connected to the upper gas distribution plate (57); A second gas uniforming plate (74) is clamped between adjacent cylinders on the lower gas distribution plate (71) and has air holes formed thereon; and side gas channels, which are connected via joints, and the channels penetrate the cover plate body and the upper gas distribution plate (57), and are ultimately connected to the gas groove at the end of the upper gas distribution plate (57).

5. A semiconductor dry etching temperature control method, based on the semiconductor dry etching equipment according to any one of claims 1 to 4, characterized in that: The following steps are involved: The low-temperature heating medium flowing back from the medium outlet (36) of the inner heating channel of the wafer heating table in the inner heating zone (67c) of the wafer heating table flows back to the heating medium storage tank (7516), and the evaporator (7519) reduces the temperature of the heating medium in the heating medium storage tank (7516); and cooperates with the storage tank heater (7517) in the heating medium storage tank (7516) to heat the heating medium; The internal medium evaporates through the evaporator (7519) and absorbs heat, thereby reducing the temperature of the heating medium passing through the evaporator (7519); Then, the internal high-temperature medium formed by the evaporation of the internal medium flows back to the inside of the condenser (7528) for cooling.

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