Pressure-maintaining aging test system and test method

Abstract

The invention relates to the technical field of wafer drying, and discloses a pressure-maintaining aging test system and a test method. The system comprises a drying chamber, a first sealing structure, a first gas source, a gas leakage detection assembly, a second gas source, a third gas source, a heating structure, a first temperature detection structure, a first pressure detection structure and a second pressure detection structure, wherein the first sealing structure is arranged outside the drying chamber and is provided with a first detection space; the first gas source is connected with the drying chamber and the first sealing structure so as to introduce first test gas; the gas leakage detection assembly detects the content of target gas in the drying chamber and / or the first detection space; the second gas source and the third gas source are connected with the drying chamber, second test gas or third test gas is introduced into the drying chamber, and a compact protection layer is formed on the inner wall surface of the drying chamber. The pressure-maintaining aging test system can complete air tightness test, pressure-maintaining test and aging process treatment of the supercritical fluid drying chamber, ensures no metal precipitation and equipment safety, and improves the cleanliness of the drying process.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer drying, and in particular to a pressure-maintaining aging test system and a test method. Background Art

[0002] Supercritical carbon dioxide drying is the mainstream technology for non-destructive drying of ultra-high aspect ratio micro-nano structures on the wafer surface after the semiconductor manufacturing process reaches the technical node below 7nm. The realization of supercritical carbon dioxide drying requires that the drying system has operating parameters above the critical point of carbon dioxide (specifically, the critical temperature is 31.2°C and the critical pressure is 7.38MPa). It is usually necessary to obtain a supercritical state of a mixture of carbon dioxide and isopropanol, which requires the process pressure of the drying system to reach 16MPa and the process temperature to reach 90°C. In addition, the metal ion precipitation of the entire drying system, including the process pipeline and the drying chamber, also has strict control indicators (specifically <1E10atoms / cm 2 ), the above process characteristics place extremely high demands on the pressure maintenance and metal precipitation rate of the entire drying system during production, assembly and use.

[0003] In the related art, the supercritical carbon dioxide drying device used for semiconductor wafer level generally predetermines the selection of pipelines and valves during the design process, including material selection and surface treatment processes, to initially ensure the sealing and cleanliness; and during the manufacturing process, the overall pressure-maintaining sealing effect is further ensured by segmented airtightness testing. However, since the permeability of the drying medium carbon dioxide increases under high temperature and high pressure, and metal dissolution and precipitation are very likely to occur, the above-mentioned design process and technical means in the manufacturing process are difficult to ensure the safety of the equipment in the early stage of equipment operation, and to control metal contamination below the index, thereby affecting the effect of the wafer non-destructive drying process. Summary of the invention

[0004] In view of this, the present invention provides a pressure-maintaining aging test system and a test method to solve the problem that the existing drying device cannot ensure safety and control metal contamination below the index value in the early stage of operation, thereby affecting the effect of the wafer non-destructive drying process and making it difficult to ensure the cleanliness of the wafer.

[0005] In the first aspect, the present invention provides a pressure-maintaining aging test system, comprising: a drying chamber, a first sealing structure, a first gas source, a gas leak detection assembly, a second gas source, a third gas source, a heating structure arranged in the drying chamber, a first temperature detection structure and a first pressure detection structure, and a third pressure detection structure arranged in the first sealing structure; the first sealing structure cover is arranged outside the drying chamber, and a first detection space is provided between the first sealing structure and the drying chamber; the first gas source is connected to the drying chamber and the first sealing structure, and the first gas source is suitable for introducing a first test gas into the drying chamber or the first detection space; the gas leak detection assembly is suitable for detecting the target gas content in the drying chamber and / or the first detection space; the second gas source is connected to the drying chamber, and the second gas source is suitable for introducing a second test gas into the drying chamber; the third gas source is connected to the drying chamber, and the third gas source is suitable for introducing a third test gas into the drying chamber, and forming a dense protective layer on the inner wall surface of the drying chamber.

[0006] Beneficial effects: In the pressure-maintaining aging test system of the present invention, the first gas source, the first sealing structure, the gas leak detection assembly, the first pressure detection structure and the third pressure detection structure cooperate with each other inside and outside the drying chamber to complete the air-tightness test of the drying chamber and verify the air-tightness of the drying chamber; the second gas source, the heating structure, the first temperature detection structure and the first pressure detection structure cooperate with each other to complete the pressure-maintaining test of the drying chamber and verify the stability of the drying chamber under long-term high temperature and high pressure conditions; the third gas source, the heating structure, the first temperature detection structure and the first pressure detection structure cooperate with each other to complete the aging process treatment of the drying chamber under high temperature and high pressure, and at the same time form a dense protective layer on the inner wall of the drying chamber to avoid the influence of metal impurities on the drying process, improve the cleanliness of the drying process, and ensure that the metal contaminants are below the index value. That is, the pressure-maintaining aging test system of the present invention can complete the airtightness test, pressure-maintaining test and aging process treatment of the supercritical fluid drying chamber, while preventing the surface of the drying chamber from being corroded by the supercritical fluid during the drying process, ensuring no metal precipitation and the safety of equipment operation, and ensuring that the system including the inner wall of the process pipeline and the drying chamber space has no metal contaminants remaining, thereby improving the cleanliness and stability of the drying process.

[0007] In an optional embodiment, the first gas source is a helium gas source, the second gas source is a nitrogen gas source, and the third gas source is a carbon dioxide gas source.

[0008] Beneficial effects: Helium has a smaller molecular weight than nitrogen and has a higher level of airtightness test for equipment. The invention uses helium for strict airtightness tests; when the airtightness is relatively loose but the pressure retention under a long-term state is tested, nitrogen with a relatively lower cost is used; carbon dioxide gas is used for aging processing to achieve gas replacement and airflow purge in the drying chamber, and form a dense protective layer under the high temperature environment in the drying chamber, reducing metal precipitation on the wall surface of the drying chamber, so that the drying process can be carried out stably in a clean environment.

[0009] In an optional embodiment, it also includes: a gas-liquid delivery pipeline, which is arranged between the first gas source, the second gas source and the third gas source and the drying chamber, the gas-liquid delivery pipeline includes a first inlet, a second inlet, a third inlet and a first outlet, and the first outlet is connected to the drying chamber; a first air inlet pipeline, one end of which is connected to the first gas source, and the other end is suitable for being connected to the first inlet of the gas-liquid delivery pipeline; a second air inlet pipeline, one end of which is connected to the second gas source, and the other end is suitable for being connected to the second inlet; a third air inlet pipeline, one end of which is connected to the third gas source, and the other end is suitable for being connected to the third inlet; a fourth air inlet pipeline, one end of which is connected to the first gas source, and the other end is connected to the first sealing structure to connect to the first detection space.

[0010] Beneficial effects: Different inlets of the gas-liquid delivery pipeline are connected to different air inlet pipelines and gas sources, so that different test gases can be introduced into the drying chamber and the gas-liquid delivery pipeline and other structures. The adjustment is flexible and convenient, which is convenient for different process tests and treatments, and has high safety and reliability.

[0011] In an optional embodiment, a first throttling component and a filter are provided on the gas-liquid transport pipeline, the first throttling component is suitable for regulating the gas flow in the gas-liquid transport pipeline, and the filter is suitable for filtering impurities in the gas passing through the gas-liquid transport pipeline.

[0012] Beneficial effects: The first throttling component is used to adjust the flow rate and flow rate of helium in the first gas source, nitrogen in the second gas source, and carbon dioxide in the third gas source flowing through the gas-liquid transportation pipeline, ensuring the stability of the gas in the gas-liquid transportation pipeline and avoiding damage to the pipeline due to impact; the filter filters impurities in the gas flowing through the gas-liquid transportation pipeline to ensure the smooth flow of the gas-liquid transportation pipeline.

[0013] In an optional embodiment, it also includes: a second sealing structure, which is covered on the gas-liquid delivery pipeline to form a second detection space outside the gas-liquid delivery pipeline; the second detection space of the second sealing structure is suitable for being connected to the first gas source.

[0014] Beneficial effect: The second sealing structure covers and seals part of the gas-liquid conveying pipeline, i.e., the multiple structures arranged thereon, to facilitate the air-tightness test of the gas-liquid conveying pipeline and the structures thereon, thereby improving the comprehensiveness of the air-tightness test of the pressure-maintaining aging test system and improving the safety performance of the pressure-maintaining aging test system.

[0015] In an optional embodiment, the gas leak detection assembly includes: a first gas leak detection structure, which is arranged in a drying chamber; a second gas leak detection structure, which is suitable for being connected to the first sealing structure and the second sealing structure respectively, and the second gas leak detection structure includes: a leak detector, a first suction gun and a second suction gun, one end of the first suction gun is connected to the leak detector, and the other end is connected to the first detection space; one end of the second suction gun is connected to the leak detector, and the other end is connected to the second detection space.

[0016] Beneficial effects: The first gas leak detection structure can be a helium leak detector based on a sensor. The gas in the drying chamber has an entry and exhaust path, and the first gas leak detection structure is not required to extract the gas. The sensor-type first gas leak detection structure has higher sensitivity and more accurate detection. The second gas leak detection structure sucks gas into the leak detector through a suction gun for analysis and detection. The first suction gun sucks a large amount of gas in the first detection space for leak detection. While the gas is pumped to balance the air pressure in the first detection space, the gas is detected. Similarly, the second suction gun set in the second sealing structure also has the function of balancing the air pressure and ensuring sufficient test gas to be detected.

[0017] In an optional embodiment, it also includes: a second temperature detection structure, which is arranged on the gas-liquid transmission pipeline to detect the medium temperature in the gas-liquid transmission pipeline; and a second pressure detection structure, which is arranged on the second sealing structure to detect the air pressure of the second detection space.

[0018] Beneficial effects: The second temperature detection structure detects the temperature on the gas-liquid transmission pipeline and the temperature inside the second sealing structure, thereby realizing real-time temperature detection of the pipeline part; the second pressure detection structure is arranged in the second sealing structure, and measures the air pressure state inside the second sealing structure. When the air pressure is high, the pressure is released in time to avoid affecting the gas flow in the gas-liquid transmission pipeline.

[0019] In a second aspect, this embodiment further provides a pressure-maintaining aging test method, comprising:

[0020] The air tightness test of the drying chamber includes: introducing a first test gas into the drying chamber or a first sealing structure covered outside the drying chamber through a first gas source, so as to form an air pressure difference between the drying chamber and the first sealing structure outside the drying chamber; obtaining a leakage rate of the first test gas in the drying chamber with a lower air pressure or in a first detection space of the first sealing structure with a lower air pressure; comparing the obtained leakage rate of the first test gas with a preset leakage rate; and, when the leakage rate of the first test gas is higher than the preset leakage rate, detecting the leakage rate of the first test gas at each connection position on the drying chamber to obtain the leakage position of the drying chamber;

[0021] The drying chamber is subjected to a pressure-maintaining test, comprising: heating the drying chamber with a heating structure so that the drying chamber has a first temperature; gradually introducing a second test gas into the drying chamber so that the drying chamber has a first pressure; the drying chamber is kept at the first temperature and the first pressure for a preset time, and a pressure drop rate of the drying chamber in multiple time periods within the preset time is obtained; the multiple pressure drop rates obtained are respectively compared with the preset pressure drop rate; and when the obtained pressure drop rate is greater than the preset pressure drop rate, the drying chamber is subjected to an airtightness test again;

[0022] The drying chamber is subjected to an aging process, including: introducing a third test gas into the drying chamber for gas blowing; heating the drying chamber and continuously introducing the third test gas so that the drying chamber has a second pressure and a second temperature; the drying chamber is maintained at the second pressure and the second temperature for a period of time to form a dense protective layer on the inner wall surface of the drying chamber.

[0023] Beneficial effects: The pressure-maintaining aging test method of the present invention can realize the airtightness test, pressure-maintaining test and aging process treatment of the drying system. When supercritical carbon dioxide drying treatment is adopted, the process temperature and pressure are guaranteed, and the precipitation of metal impurities is guaranteed to be below the index.

[0024] In an optional embodiment, in the step of performing a pressure-maintaining test on the drying chamber, a second test gas is gradually introduced into the drying chamber so that the drying chamber has a first pressure, including: controlling the gas flow rate of the second test gas to gradually fill the drying chamber in a gradient increasing manner.

[0025] Beneficial effect: When the second test gas is gradually introduced into the drying chamber, the gas flow of the second test gas is controlled to be gradually filled into the drying chamber in a gradient increasing manner, which can effectively avoid damage to the pipeline due to over-flow of airflow and ensure the reliability of the pipeline during the test process.

[0026] In an optional embodiment, in the step of performing an aging process on the drying chamber, before introducing a third test gas into the drying chamber so that the drying chamber has a second pressure, the step further includes: in the drying chamber where no dense protective layer is formed, performing a surface wetting process on a first wafer placed in the drying chamber through a third gas source; obtaining a first scan image of the surface of the first wafer after the wetting process, and a first metal particle density value on the surface of the first wafer;

[0027] After a dense protective layer is formed on the inner wall surface of the drying chamber, the method also includes: in the drying chamber where the dense protective layer is formed, performing surface wetting treatment on a second wafer placed in the drying chamber by a third gas source; obtaining a second scanning image of the surface of the second wafer after the wetting treatment, and a second metal particle density value of the surface of the second wafer; comparing the obtained second scanning image with the first scanning image to obtain the degree of improvement in the cleanliness of the drying chamber, and when the second metal particle density value is less than the target metal particle density value, the drying chamber after the aging process treatment is used for the drying process.

[0028] Beneficial effect: By comparing the metal particle density on the surface of different wafers treated with the third test gas and those not treated with the third test gas, it is verified whether the cleanliness of the supercritical gas drying after aging in the drying chamber meets the standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 is a structural schematic diagram of a pressure-maintaining aging test system according to an embodiment of the present invention;

[0031] Figure 2 is a flowchart of a pressure-maintaining aging test method according to an embodiment of the present invention;

[0032] Figure 3 It is a flowchart of a negative pressure air tightness test performed by a pressure-maintaining aging test method according to an embodiment of the present invention;

[0033] Figure 4 Schematic diagram of a negative pressure air tightness test in a pressure-maintaining aging test method according to an embodiment of the present invention;

[0034] Figure 5 It is a flowchart of a positive pressure air tightness test performed by a pressure-maintaining aging test method according to an embodiment of the present invention;

[0035] Figure 6 is a schematic diagram of a positive pressure air tightness test in a pressure-maintaining aging test method according to an embodiment of the present invention;

[0036] Figure 7 It is a flowchart of performing a pressure-maintaining test in the pressure-maintaining aging test method according to an embodiment of the present invention;

[0037] Figure 8 is a schematic diagram of a pressure-maintaining test in a pressure-maintaining aging test method according to an embodiment of the present invention;

[0038] Fig. 9 This is a flowchart of the aging process in the pressure-maintaining aging test method of an embodiment of the present invention.

[0039] Fig.10 It is a schematic diagram of the aging process in the pressure-maintaining aging test method according to an embodiment of the present invention.

[0040] Description of reference numerals:

[0041] 1. Drying chamber; 2. First sealing structure; 201. First detection space; 3. First gas source; 4. Second gas source; 5. Third gas source; 6. Heating structure; 7. First temperature detection structure; 8. First pressure detection structure; 9. Gas-liquid delivery pipeline; 901. First inlet; 902. Second inlet; 903. Third inlet; 904. First outlet; 905. First opening and closing valve; 906. Second opening and closing valve; 907. Third opening and closing valve; 908. Fourth opening and closing valve; 10. First air intake pipeline; 1001. Fifth opening and closing valve; 11. Second air intake pipeline; 1101. One-way valve; 1102. Sixth opening and closing valve; 12. Third air intake pipeline; 1201. Seventh opening and closing valve; 13. Fourth air intake pipeline; 1301. Eighth opening and closing valve; 14. First throttling assembly; 15. Filter; 16. The second sealing structure; 1601, the second detection space; 17, the first gas leak detection structure; 1801, the leak detector; 1802, the first suction gun; 1803, the second suction gun; 19, the second temperature detection structure; 20, the second pressure detection structure; 21, the first bypass pipeline; 2101, the overflow valve; 2102, the ninth opening and closing valve; 22, the second bypass pipeline; 2201, the tenth opening and closing valve; 23, the discharge pipeline; 2301, the back pressure valve; 2302, the eleventh opening and closing valve; 24, the escape pipeline; 2401, the twelfth opening and closing valve; 25, the vacuum pump; 2501, the thirteenth opening and closing valve; 26, the first nozzle; 27, the second nozzle; 28, the nozzle; 29, the flow meter; 30, the second throttling assembly; 31, the third pressure detection structure; 32, the fifth intake pipeline; 3201, the fourteenth opening and closing valve. DETAILED DESCRIPTION

[0042] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is understandable that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings. In the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concept of the present invention. Various structural schematic diagrams according to embodiments of the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified for the purpose of clear expression, and some details may be omitted. The shapes of various regions and structures shown in the figures and the relative sizes and positional relationships between them are only exemplary, and may be deviated in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / structures with different shapes, sizes, and relative positions according to actual needs.

[0043] In the related art, the supercritical carbon dioxide drying device used for semiconductor wafer level generally predetermines the selection of pipelines and valves during the design process, including material selection and surface treatment process, to initially ensure the sealing and cleanliness; and during the manufacturing process, the overall pressure-maintaining sealing effect is further ensured by segmented airtightness testing. However, since the permeability of the drying medium carbon dioxide increases under high temperature and high pressure, and metal dissolution and precipitation are very likely to occur, these solutions are difficult to ensure the safety of the equipment in the early stage of equipment operation, that is, to ensure that the carbon dioxide is at a supercritical temperature and pressure, and to control metal contamination at 1E10atoms / cm 2 The following will affect the cleanliness of the wafer surface and the stability of the non-destructive drying process.

[0044] Based on this, Figure 1 As shown, this embodiment provides a pressure-maintaining aging test system, including: a drying chamber 1, a first sealing structure 2, a first gas source 3, a gas leak detection assembly, a second gas source 4, a third gas source 5, a heating structure 6 arranged in the drying chamber 1, a first temperature detection structure 7 and a first pressure detection structure 8, and a third pressure detection structure 31 arranged in the first sealing structure 2; the first sealing structure 2 is covered outside the drying chamber 1, and a first detection space 201 is provided between the first sealing structure 2 and the drying chamber 1; the first gas source 3 and the drying chamber 1 and a first sealing structure 2 are connected, the first gas source 3 is suitable for passing the first test gas into the drying chamber 1 or the first detection space 201; the gas leak detection assembly is suitable for detecting the target gas content in the drying chamber 1 and / or the first detection space 201; the second gas source 4 is connected to the drying chamber 1, and the second gas source 4 is suitable for passing the second test gas into the drying chamber 1; the third gas source 5 is connected to the drying chamber 1, and the third gas source 5 is suitable for passing the third test gas into the drying chamber 1, and forming a dense protective layer on the inner wall surface of the drying chamber 1.

[0045] Specifically, the above-mentioned drying chamber 1 is made of stainless steel. On the first aspect, the first sealing structure 2 is covered outside the drying chamber 1, and forms a first detection space 201 between the outer wall of the drying chamber 1 and the inner wall of the first sealing structure 2. The first test gas is filled into the drying chamber 1 or the first detection space 201 through the first gas source 3, so that an air pressure difference is formed between the drying chamber 1 and the first detection space 201 outside it. The first pressure detection structure 8 is used to detect the air pressure of the drying chamber 1, and the third pressure detection structure 31 is used to detect the air pressure of the first detection space 201 formed between the first sealing structure 2 and the drying chamber 1 to ensure the formation of the air pressure difference, so that under the condition of the air pressure difference, the gas leakage degree and leakage position of the drying chamber 1 are detected by the gas leak detection component to ensure the air tightness of the drying chamber 1 when it is put into use. The gas leak detection component may include a component that is only arranged in the drying chamber 1 or is only arranged to be connected to the first sealing structure 2, so as to respectively detect the target gas content contained in the drying chamber 1 or the first detection space 201. The target gas here may be a small amount of the first test gas detected in the drying chamber 1, and this small amount of the first test gas is a small amount of gas that is directly introduced into the first detection space 201 but leaks into the drying chamber 1; of course, the target gas may also be a small amount of the first test gas detected in the first detection space 201, and this small amount of the first test gas is a small amount of gas that is directly introduced into the drying chamber 1 but leaks into the first test space. Of course, it is not excluded that the component is simultaneously arranged in the drying chamber 1 and connected to the first sealing structure 2, so as to detect the target gas content in these two spaces at the same time.

[0046] Secondly, the heating structure 6 located in the drying chamber 1 heats the inside of the drying chamber 1. For example, the heating structure 6 can be a heating plate or a heating rod, and the heating method can be electromagnetic heating, infrared heating or resistance heating. The real-time temperature is detected by the first temperature detection structure 7 to form a high-temperature environment required for the supercritical carbon dioxide drying process in the drying chamber 1. The second gas source 4 introduces a second test gas into the drying chamber 1. The first pressure detection structure 8 detects the real-time air pressure to form a high-pressure environment in the drying chamber 1, and after a period of time, the first pressure detection structure 8 located in the drying chamber 1 can detect the real-time air pressure. It is possible to obtain the pressure value in the interval time period and calculate the pressure drop rate. Then, by comparing the calculated pressure drop rate with the set target pressure drop rate of the pressure holding test, it is determined whether the drying chamber 1 is stable under a long-term high temperature and high pressure state to complete the pressure holding test. Specifically, if the calculated pressure drop rate is less than the target pressure drop rate, the pressure holding is successful, otherwise the pressure holding fails, and the air tightness test of each position of the drying chamber 1 is re-performed to obtain the leakage position and perform corresponding repair treatment; in addition, the heating structure 6 in this embodiment is arranged in two groups, upper and lower, in the drying chamber 1 to ensure all-round heating of the internal space of the drying chamber 1.

[0047] On the third aspect, the pressure-maintaining aging test system of this embodiment introduces the third test gas into the drying chamber 1 through the third gas source 5 to form an airflow impact on the inner wall surface of the drying chamber 1. At this time, the drying chamber 1 is heated by the heating structure 6, and a high-pressure and high-temperature environment is formed in the drying chamber 1 and the heat is kept for a certain period of time. While completing the aging process, the third test gas reacts with the stainless steel drying chamber 1 to form a dense protective layer on the inner wall surface, which effectively prevents the inner wall surface of the drying chamber 1 from being corroded during the drying process and avoids the precipitation of metal pollutants during the drying process.

[0048] In the pressure-maintaining aging test system of this embodiment, the first gas source 3, the first sealing structure 2, the gas leak detection assembly, the first pressure detection structure 8 and the third pressure detection structure 31 cooperate with each other at the drying chamber 1 to complete the air-tightness test of the drying chamber 1 and verify the air-tightness of the drying chamber 1; the second gas source 4, the heating structure 6, the first temperature detection structure 7 and the first pressure detection structure 8 cooperate with each other to complete the pressure-maintaining test of the drying chamber 1 and verify the stability of the drying chamber 1 under long-term high temperature and high pressure conditions; the third gas source 5, the heating structure 6, the first temperature detection structure 7 and the first pressure detection structure 8 cooperate with each other to complete the aging process treatment of the drying chamber 1, and at the same time form a dense protective layer on the inner wall surface of the drying chamber 1 to avoid the influence of metal impurities on the drying process, improve the cleanliness of the drying process, and ensure that the metal contaminants are below the index value. That is, the pressure-maintaining aging test system of this embodiment can complete the airtightness test, pressure-maintaining test and aging process treatment of the supercritical fluid drying chamber 1, while preventing the surface of the drying chamber 1 from being corroded by the supercritical fluid during the drying process, ensuring no metal precipitation and the safety of equipment operation, and ensuring that the system including the inner wall of the process pipeline and the space of the drying chamber 1 are free of metal contaminants, thereby improving the cleanliness and stability of the drying process.

[0049] In this embodiment, the first gas source 3 is a helium gas source, the second gas source 4 is a nitrogen gas source, and the third gas source 5 is a carbon dioxide gas source. Helium has a smaller molecular weight than nitrogen, and has a higher level of airtightness test for the equipment. In this embodiment, helium is used for strict airtightness test; when the airtightness is relatively loose but the pressure retention under a long-term state is tested, nitrogen with a relatively lower cost is used. Of course, if it is a semiconductor device with ultra-high standards, helium can also be used for pressure holding test; carbon dioxide gas is used for aging processing to achieve gas replacement and airflow purge in the drying chamber 1, and form a dense protective layer under the high temperature and high pressure environment in the drying chamber 1, reduce the metal precipitation on the inner wall of the drying chamber 1, and make the drying process stable in a clean environment. Of course, the third gas source 5 is a gas source structure containing liquid carbon dioxide. The third gas source 5 can heat and pressurize the liquid carbon dioxide to release gaseous carbon dioxide to meet the gas replacement and purge, but it does not exclude direct release in the form of liquid carbon dioxide.

[0050] like Figure 1As shown, the pressure-maintaining aging test system of this embodiment also includes: a gas-liquid delivery pipeline 9, a first air inlet pipeline 10, a second air inlet pipeline 11, a third air inlet pipeline 12 and a fourth air inlet pipeline 13. The gas-liquid delivery pipeline 9 is arranged between the first air source 3, the second air source 4 and the third air source 5 and the drying chamber 1. The gas-liquid delivery pipeline 9 includes a first inlet 901, a second inlet 902, a third inlet 903 and a first outlet 904, and the first outlet 904 is connected to the drying chamber 1; one end of the first air inlet pipeline 10 is connected to the first air source 3, and the other end is suitable for communicating with the first inlet 901 of the gas-liquid delivery pipeline 9; one end of the second air inlet pipeline 11 is connected to the second air source 4, and the other end is suitable for communicating with the second inlet 902; one end of the third air inlet pipeline 12 is connected to the third air source 5, and the other end is suitable for communicating with the third inlet 903; one end of the fourth air inlet pipeline 13 is connected to the first air source 3, and the other end is connected to the first sealing structure 2 to connect to the first detection space 201.

[0051] Specifically, the inlet end of the gas-liquid delivery pipeline 9 is divided into a first inlet 901 and a third inlet 903, a second inlet 902 is arranged at the middle position of the gas-liquid delivery pipeline 9, and a first outlet 904 is arranged at the outlet end of the gas-liquid delivery pipeline 9. The first inlet 901 and the third inlet 903 are connected to the first air inlet pipeline 10 and the third air inlet pipeline 12 respectively, the other end of the first air inlet pipeline 10 is connected to the first gas source 3, and a fifth on-off valve 1001 is arranged on the first air inlet pipeline 10 to control whether the first test gas, i.e., helium, can enter the gas-liquid delivery pipeline 9; one end of the second air inlet pipeline 11 is connected to the second inlet 902, and the other end is connected to the second gas source 4, a one-way valve 1101 and a sixth on-off valve 1102 are arranged on the second air inlet pipeline 11, and the one-way valve 1101 controls whether the second test gas, i.e., nitrogen, in the second gas source 4 can only enter from the second gas source 4 4 flows to the gas-liquid delivery pipeline 9, but cannot flow in the reverse direction, and the sixth on-off valve 1102 controls whether the nitrogen gas can enter the gas-liquid delivery pipeline 9; the other end of the third air inlet pipeline 12 is connected to the third gas source 5, and the seventh on-off valve 1201 is arranged on the third air inlet pipeline 12 to control whether the third test gas, i.e., the carbon dioxide gas, can enter the gas-liquid delivery pipeline 9; the fourth air inlet pipeline 13 is connected to the first gas source 3 and the first sealing structure 2, and the eighth on-off valve 1301 is arranged on the fourth air inlet pipeline 13 near the first sealing structure 2 to control the on-off of the first gas source 3 and the first test space. In addition, a first on-off valve 905 is provided near the inlet end of the gas-liquid delivery pipeline 9 to control the on-off of the inlet end of the gas-liquid delivery pipeline 9. For example, when the second test gas is introduced into the gas-liquid delivery pipeline 9, it can ensure that the second test gas does not flow into the first air inlet pipeline 10 and the third air inlet pipeline 12, thereby improving the cleanliness of the first gas source 3 and the third gas source 5 and ensuring the safety of the system; and a fourth on-off valve 908 is provided near the outlet end of the gas-liquid delivery pipeline 9 to control the on-off of the outlet end of the gas-liquid delivery pipeline 9, enhance the on-off control of the gas-liquid delivery pipeline 9 and the drying chamber 1, and avoid the interference of the airflow in the gas-liquid delivery pipeline 9 with the drying chamber 1 when it does not need to flow into the drying chamber 1.

[0052] In this embodiment, when the first test gas is introduced into the drying chamber 1, the first air inlet pipe 10 and the gas-liquid delivery pipe 9 are connected, that is, the air tightness test of the first air inlet pipe 10 and the gas-liquid delivery pipe 9 can be realized; when the second test gas is introduced into the drying chamber 1, the second air inlet pipe 11 and the gas-liquid delivery pipe 9 are connected, that is, the basis for pressure maintenance test of the second air inlet pipe 11 and the gas-liquid delivery pipe 9 is provided; when the third test gas is introduced into the drying chamber 1, the third air inlet pipe 12 and the gas-liquid delivery pipe 9 are connected, that is, the aging test of the third air inlet pipe 12 and the gas-liquid delivery pipe 9 can be realized. Of course, during the circulation of the third test gas, a dense protective layer will also be formed on the inner wall surface of the gas-liquid delivery pipe 9, which further reduces the risk of contamination caused by gas circulation and ensures the accuracy of various tests.

[0053] In one embodiment, a first throttling component 14 and a filter 15 are also provided on the above-mentioned gas-liquid transport pipeline 9. The first throttling component 14 is suitable for adjusting the gas flow in the gas-liquid transport pipeline 9, and the filter 15 is suitable for filtering impurities in the gas passing through the gas-liquid transport pipeline 9.

[0054] Specifically, the first throttling component 14 in the present solution is used to adjust the flow rate and flow rate of the helium gas in the first gas source 3, the nitrogen gas in the second gas source 4, and the carbon dioxide gas in the third gas source 5 flowing through the gas-liquid delivery pipeline 9, so as to ensure the stability of the gas in the gas-liquid delivery pipeline 9 and avoid damaging the pipeline due to impact; the filter 15 filters the impurities of the gas flowing through the gas-liquid delivery pipeline 9 to ensure the smooth flow of the gas-liquid delivery pipeline 9. In addition, a second opening and closing valve 906 is provided between the first throttling component 14 and the filter 15, and a third opening and closing valve 907 is provided between the filter 15 and the fourth opening and closing valve 908, that is, the first opening and closing valve 905 and the second opening and closing valve 906 are provided on both sides of the first throttling component 14, and the second opening and closing valve 906 and the third opening and closing valve 907 are provided on both sides of the filter 15, so as to facilitate the replacement of the first throttling component 14 and the filter 15 without affecting the connection relationship and stability of other structures.

[0055] In one embodiment, the pressure-maintaining aging test system also includes: a second sealing structure 16 covered on the gas-liquid delivery pipeline 9 to form a second detection space 1601 outside the gas-liquid delivery pipeline 9; the second detection space 1601 of the second sealing structure 16 is suitable for being connected to the first gas source 3.

[0056] Specifically, the first opening and closing valve 905, the first throttling assembly 14, the second opening and closing valve 906, the filter 15 and the third opening and closing valve 907, as well as the one-way valve 1101 and the sixth opening and closing valve 1102 on the second air intake line 11 are all located in the second sealing structure 16 to further seal the above structures. In addition, the second sealing structure 16 is also connected to the first air source 3 through the fifth air intake line 32, and the fourteenth opening and closing valve 3201 is arranged on the fifth air intake line 32 to control the connection and disconnection of the first air source 3 and the second detection space 1601 of the second sealing structure 16. In this way, the connection arrangement of the first air source 3 and the second sealing structure 16 can realize the air tightness test of the above structures located in the second sealing structure 16, further improve the comprehensiveness of the air tightness test of the pressure-maintaining aging test system, and improve the safety performance of the pressure-maintaining aging test system.

[0057] In one embodiment, the above-mentioned gas leak detection assembly includes: a first gas leak detection structure 17 and a second gas leak detection structure, the first gas leak detection structure 17 is arranged in the drying chamber 1; the second gas leak detection structure is suitable for being connected to the first sealing structure 2 and the second sealing structure 16 respectively, and the second gas leak detection structure includes: a leak detector 1801, a first suction gun 1802 and a second suction gun 1803, one end of the first suction gun 1802 is connected to the leak detector 1801, and the other end is connected to the first detection space 201; one end of the second suction gun 1803 is connected to the leak detector 1801, and the other end is connected to the second detection space 1601.

[0058] The first gas leak detection structure 17 can be a helium leak detector based on a sensor, and the second gas leak detection structure needs to suck gas into the leak detector 1801 through a suction gun for analysis and detection. This is because the first gas leak detection structure 17 is arranged in the drying chamber 1, and the drying chamber 1 is also connected with a vacuum pump 25 and a first bypass pipeline 21. The vacuum pump 25 is connected to the first nozzle 26 located in the drying chamber 1, and a thirteenth on-off valve 2501 is arranged between the vacuum pump 25 and the first nozzle 26 to control the on-off of the vacuum pump 25. 5. The thirteenth on-off valve 2501 and the first nozzle 26 can realize the extraction of gas in the drying chamber 1. The first bypass pipeline 21 has the function of exhausting the gas in the drying chamber 1, and the drying chamber 1 has a second nozzle 27 for inputting the first test gas, the second test gas and the third test gas from the gas-liquid delivery pipeline 9. Therefore, the gas in the drying chamber 1 has an entry and exhaust path, and the first gas leak detection structure 17 is not required to extract the gas. The sensor-type first gas leak detection structure 17 has higher sensitivity and more accurate detection. However, the first sealing structure 2 only has a nozzle 28 connected to the first gas source 3, and does not have a gas exhaust path. The first suction gun 1802 absorbs a large amount of gas in the first detection space 201 for leak detection, and realizes gas detection while balancing the air pressure in the first detection space 201 by exhausting gas; similarly, the second suction gun 1803 set in the second sealing structure 16 also has the above-mentioned function of balancing the air pressure and ensuring sufficient test gas to be detected.

[0059] refer to Figure 1 The pressure-maintaining aging test system of this embodiment also includes: a second temperature detection structure 19 and a second pressure detection structure 20. The second temperature detection structure 19 is arranged on the gas-liquid delivery pipeline 9, and the second pressure detection structure 20 is arranged on the second sealing structure 16 to detect the air pressure of the second detection space 1601.

[0060] Specifically, the second temperature detection structure 19 is arranged between the first opening and closing valve 905 and the first throttling assembly 14 to detect the temperature on the gas-liquid delivery pipeline 9 and the temperature inside the second sealing structure 16, so as to realize real-time temperature detection of the pipeline part; the second pressure detection structure 20 is arranged in the second sealing structure 16 to measure the air pressure state inside the second sealing structure 16, and release the pressure in time when the air pressure is high, so as to avoid affecting the gas flow in the gas-liquid delivery pipeline 9; under the condition that the gas-liquid delivery pipeline 9 has temperature detection and pressure detection, the first gas source 3 passes the first test gas into the second sealing structure 16, that is, the second detection space 1601, through the fifth air inlet pipeline 32 and the fourteenth opening and closing valve 3201, so as to provide the gas-liquid delivery pipeline 9 with conditions for high temperature and high pressure pressure maintenance test and aging process treatment, thereby realizing the pressure maintenance test and aging process treatment of the gas-liquid delivery pipeline 9 under high temperature and high pressure.

[0061] In addition, a third pressure detection structure 31 is provided in the first sealing structure 2 to detect the air pressure in the first detection space 201 to meet the relative air pressure requirements of the first detection space 201 and the drying chamber 1, while preventing the first detection space 201 from having excessive air pressure and affecting the drying chamber 1.

[0062] In one embodiment, the pressure-maintaining aging test system also includes: a first bypass line 21, a second bypass line 22 and an escape line 24, one end of the first bypass line 21 is connected to the drying chamber 1, and the other end is suitable for connecting to the exhaust line 23; one end of the second bypass line 22 is connected to the gas-liquid delivery line 9, and the other end is suitable for connecting to the exhaust line 23; one end of the escape line 24 is connected to the gas-liquid delivery line 9, and the other end is suitable for connecting to the second detection space 1601.

[0063] Specifically, the first bypass pipeline 21 is used for gas discharge from the drying chamber 1, the second bypass pipeline 22 is used for gas discharge from the gas-liquid delivery pipeline 9, and the escape pipeline 24 is used to adjust the air pressure of the gas-liquid delivery pipeline 9 while ensuring the connectivity between the gas-liquid delivery pipeline 9 and the second detection space 1601, so as to prevent external environmental gas from entering the gas-liquid delivery pipeline 9.

[0064] In addition, the first bypass pipeline 21 is provided with an overflow valve 2101 and a ninth opening and closing valve 2102 near the outlet end, and the overflow valve 2101 adjusts the pressure in the first bypass pipeline 21 to avoid damaging the pipeline; the second bypass pipeline 22 is provided with a tenth opening and closing valve 2201, and the inlet end of the second bypass pipeline 22 is located between the first throttling component 14 and the second opening and closing valve 906 on the gas-liquid transmission pipeline 9, and the outlet end is connected to the discharge pipeline 23; the escape pipeline 24 is provided with a second throttling component 30 and a twelfth opening and closing valve 2401, and the inlet end of the escape pipeline 24 is located between the first throttling component 14 and the second opening and closing valve 906 on the gas-liquid transmission pipeline 9, and the outlet end is connected to the discharge pipeline 23; The outlet end of the escape line 24 is located in the second detection space 1601, between the first throttling assembly 14 and the inlet end of the second bypass line 22; the discharge line 23 is provided with a flow meter 29, a back pressure valve 2301 and an eleventh opening and closing valve 2302; the inlet end of the discharge line 23 is connected to the outlet ends of the first bypass line 21 and the second bypass line 22; the outlet end of the discharge line 23 is connected to the external environment; the back pressure valve 2301 adjusts the pressure change and exhaust volume in the discharge line; the flow meter 29 detects the amount of exhaust gas in the first bypass line 21 and the second bypass line 22.

[0065] refer to Figure 2 The present embodiment further provides a pressure-maintaining aging test method, comprising: step S201, performing an airtightness test on the drying chamber 1, step S202, performing a pressure-maintaining test on the drying chamber 1, and step S203, performing an aging process on the drying chamber 1.

[0066] In this embodiment, the above step S201, performing an airtightness test on the drying chamber 1, includes the following steps:

[0067] In step S2011 , the first gas source 3 introduces a first test gas into the drying chamber 1 or the first sealing structure 2 disposed outside the drying chamber 1 , so as to form a pressure difference between the drying chamber 1 and the first sealing structure 2 outside the drying chamber 1 .

[0068] Exemplarily, in the present embodiment, the first gas source 3 is a helium gas source, and the first test gas in the first gas source 3 enters the drying chamber 1 through the first air inlet pipeline 10, the gas-liquid delivery pipeline 9 and the second nozzle 27, so that the drying chamber 1 has a higher pressure than the first detection space 201 of the external first sealing structure 2; or the first test gas in the first gas source 3 enters the first test space of the first sealing structure 2 through the fourth air inlet pipeline 13, so that the drying chamber 1 has a lower pressure than the first detection space 201 of the external first sealing structure 2, and finally forms a pressure difference between the drying chamber 1 and the first detection space 201 of the external first sealing structure 2.

[0069] Step S2012, obtaining the leakage rate of the first test gas in the drying chamber 1 with a relatively low air pressure or in the first detection space 201 of the first sealing structure 2 with a relatively low air pressure.

[0070] Due to the pressure difference, the gas in the space with higher pressure tends to flow to the space with lower pressure. Therefore, in this embodiment, the leakage of the first test gas is collected and detected on the side with lower pressure, and the leakage rate is obtained according to the process time.

[0071] Step S2013: comparing the obtained leakage rate of the first test gas with a preset leakage rate.

[0072] The leakage rate of the first test gas collected and detected is compared with the maximum leakage rate required by the supercritical carbon dioxide drying process of the drying chamber 1, that is, the preset leakage rate, to evaluate whether the airtightness of the drying chamber 1 meets the requirements.

[0073] Step S2014 , when the leakage rate of the first test gas is higher than a preset leakage rate, detecting the leakage rate of the first test gas at each connection position on the drying chamber 1 to obtain the leakage position of the drying chamber 1 .

[0074] Specifically, the connection positions of the drying chamber 1 include the setting position of the first nozzle 26, the setting position of the second nozzle 27, and the lead-out position of the first bypass line 21. When the leakage rate of the detected first test gas is higher than the maximum leakage rate allowed by the drying process, that is, the preset leakage rate, it means that the gas leakage of the drying chamber 1 exceeds the standard, and the specific leakage position needs to be determined to ensure the airtightness of the drying chamber 1 for supercritical carbon dioxide drying. Of course, it is not ruled out that other drying processes have different preset leakage rates.

[0075] In the pressure-maintaining aging test method of this embodiment, the air tightness test of the drying chamber 1 is performed. By forming an air pressure difference between the drying chamber 1 to be tested and its external space, the gas leakage amount of the drying chamber 1 is accurately obtained by using the pressure difference, and the gas leakage rate is obtained according to the specific processing time. Then, it is compared with the preset leakage rate allowed by the drying chamber 1, and finally the air tightness of the drying chamber 1 is verified to ensure the reliability of the drying chamber 1 during the drying process.

[0076] Specifically, there are two types of airtightness tests on the drying chamber 1 , one is to perform an internal leakage test on the drying chamber 1 with negative pressure, and the other is to perform an external leakage test on the drying chamber 1 with positive pressure.

[0077] refer to Figure 3 and Figure 4 In this embodiment, the internal leakage detection of the negative pressure drying chamber 1 is performed, that is, the internal air pressure of the drying chamber 1 is lower than the air pressure of the external space, and specifically includes the following steps:

[0078] In step S2011a, the vacuum pump 25 evacuates the drying chamber 1 through the first nozzle 26, and the first gas source 3 introduces a first test gas into the first sealing structure 2 disposed outside the drying chamber 1 to form a pressure difference between the drying chamber 1 and the first sealing structure 2 outside the drying chamber 1.

[0079] Specifically, refer to Figure 4In the path indicated by the black bold arrow, the first test gas flows out from the first gas source 3, passes through the eighth opening and closing valve 1301 on the fourth gas inlet pipeline 13 and the nozzle 28 in the first sealing structure 2, and enters the first detection space 201 inside the first sealing structure 2. At the same time, the first test gas flows out from the first gas source 3, passes through the fifth gas inlet pipeline 32 and the fourteenth opening and closing valve 3201 thereon, and enters the second detection space 1601 inside the second sealing structure 16. In the embodiment, the first test gas is set to flow out until the gas pressure in the first sealing structure 2 and the second sealing structure 16 increases to 0.10MPa to 0.11MPa, and then the first gas source 3, the eighth opening and closing valve 1301 and the fourteenth opening and closing valve 3201 are closed. In this embodiment, a vacuum pump 25 is provided to be connected to a first nozzle 26 provided in the drying chamber 1, and the drying chamber 1 is evacuated before the first test gas is filled. Specifically, after the vacuum pump 25 is connected to a power source and preheated for five minutes, the drying chamber 1 is evacuated for 20 minutes to 30 minutes. When the internal air pressure of the drying chamber 1 drops to 0.1Pa to 10Pa, preferably 1Pa, the vacuum pump 25 is turned off, and the drying chamber 1 is kept at a low vacuum state for 10 minutes.

[0080] Step S2012a, obtaining the leakage rate of the first test gas in the drying chamber 1 with a relatively low air pressure or in the first detection space 201 of the first sealing structure 2 with a relatively low air pressure.

[0081] Specifically, the first gas leak detection structure 17 in the drying chamber 1 is turned on to detect the leakage rate of the first test gas inside the drying chamber 1 , and the leakage rate of the first test gas after stabilization is obtained after waiting for 10 to 20 minutes.

[0082] Step S2013a: comparing the obtained leakage rate of the first test gas with a preset leakage rate.

[0083] In this embodiment, the preset leakage rate is set to 1×10 -3 Pam 3 / s; the stabilized content value of the first test gas measured by the first gas leak detection structure 17 is divided by the process processing time to obtain the actual leakage rate of the first test gas for comparison with the preset leakage rate. Compared with the variable leakage amount, the leakage rate after the leakage amount divided by the time, which is similar to the averaged leakage rate, is more accurate and representative for measuring the air tightness.

[0084] Step S2014a, when the leakage rate of the first test gas is higher than the preset leakage rate, the leakage rate of the first test gas at each connection position on the drying chamber 1 and the gas-liquid delivery pipeline 9 is obtained to obtain the leakage position.

[0085] Specifically, if the leakage rate, i.e., the ratio of the leakage volume of the first test gas measured by the first gas leak detection structure 17 to the time is controlled within 1×10-3 Pam 3 / s or less, the sealing performance of the drying chamber 1 is good; if the leakage rate is higher than 1×10 - 3 Pam 3 / s, then open Figure 4 The first sealing structure 2 and the second sealing structure 16 shown, when the drying chamber 1 is under negative pressure, spray helium to various connections, including the first nozzle 26, the second nozzle 27, the lead-out position of the first bypass pipeline 21 and the connections of various components of the gas-liquid delivery pipeline 9, and use the first gas leak detection structure 17 and the second gas leak detection structure to determine the leakage position.

[0086] refer to Figure 5 and Figure 6 In this embodiment, the internal leakage detection is performed on the positive pressure drying chamber 1, that is, the internal air pressure of the drying chamber 1 is greater than the air pressure of the external space, and specifically includes the following steps:

[0087] In step S2011b, the first gas source 3 introduces the first test gas into the drying chamber 1 through the gas-liquid delivery pipeline 9 to form a pressure difference between the drying chamber 1 and the first sealing structure 2 outside the drying chamber 1 .

[0088] Specifically, open the second nozzle 27 of the drying chamber 1, all switch structures including the first throttling assembly 14 and the filter 15 on the gas-liquid delivery pipeline 9, the first air intake pipeline 10 and the first air source 3, close other valves, increase the pressure in the drying chamber 1 to 0.12MPa~0.15MPa, and then close the relevant valve structure to stop the air intake of the drying chamber 1.

[0089] Step S2012b, obtaining the leakage rate of the first test gas in the drying chamber 1 with a relatively low air pressure or in the first detection space 201 of the first sealing structure 2 with a relatively low air pressure.

[0090] Specifically, the second gas leak detection structure is opened, the first suction gun 1802 extracts the first test gas in the first detection space 201, the second suction gun 1803 extracts the first test gas in the second detection space 1601, and the leakage rate of the absorbed first test gas is obtained by analyzing with the leak detector 1801.

[0091] Step S2013b: comparing the obtained leakage rate of the first test gas with a preset leakage rate.

[0092] In this embodiment, the preset leakage rate is used for comparison and measurement, that is, the preset leakage rate is set to 1×10 -3 Pam 3 / s, the leakage amount of the first test gas measured by the leak detector 1801 is divided by the time to obtain the leakage rate of the first test gas, which is compared with the preset leakage rate. Similarly, the leakage amount divided by the time, which is similar to the leakage rate after averaging processing, is more accurate and representative for measuring air tightness.

[0093] Step S2014b, when the leakage rate of the first test gas is higher than the preset leakage rate, the concentration of the first test gas at each connection position on the drying chamber 1 and the gas-liquid delivery pipeline 9 is detected to obtain the leakage position.

[0094] Specifically, if the leakage rate, i.e., the leakage amount of the first test gas measured by the leak detector 1801 divided by the time, is controlled within 1×10 -3 Pam 3 / s or less, the sealing performance of the drying chamber 1 is good; if the leakage rate is higher than 1×10 -3 Pam 3 / s, then open Figure 6 The first sealing structure 2 and the second sealing structure 16 shown, when the drying chamber 1 is under negative pressure, spray helium gas to each connection, including the first nozzle 26, the second nozzle 27, the first bypass pipeline 21 and the lead-out positions of the connection points of each component of the gas-liquid delivery pipeline 9, and use the first gas leak detection structure 17 to determine the leakage position.

[0095] In this embodiment, the working pressure of the pipeline in the drying chamber 1 for storing the supercritical fluid is 16 MPa, the temperature is 120° C., and nitrogen is used as the working gas.

[0096] Figure 7 For a flowchart of the pressure holding test of the drying chamber 1, refer to Figure 7 and Figure 8 The above step S202 performs a pressure test on the drying chamber 1, and includes the following steps:

[0097] In step S2021 , the heating structure 6 heats the drying chamber 1 so that the drying chamber 1 has a first temperature.

[0098] Specifically, the drying chamber 1 is heated by the heating structure 6, and the first temperature detection structure 7 is observed to ensure that the drying chamber 1 is heated to 120°C. In subsequent steps, the temperature of the drying chamber 1 is always kept within the range of 100°C to 120°C.

[0099] Step S2022 , gradually introducing the second test gas into the drying chamber 1 , so that the drying chamber 1 has a first pressure.

[0100] Specifically, the second test gas, namely nitrogen, is Figure 8The direction indicated by the black bold arrow is output from the second gas source 4, flows through the second air inlet pipeline 11 and the gas-liquid delivery pipeline 9 and gradually flows into the drying chamber 1. At this time, the first bypass pipeline 21 and the second bypass pipeline 22 are opened. After the gas replacement in the drying chamber 1 and related pipelines is completed, the valves on the first bypass pipeline 21 and the second bypass pipeline 22 are closed, so that the pressure in the drying chamber 1 and the second air inlet pipeline 11, the gas-liquid delivery pipeline 9, the first bypass pipeline 21 and the second bypass pipeline 22 reaches 1.1 times to 1.5 times the pipeline use pressure, that is, the second gas source 4 is closed after the first pressure is between 17.6MPa and 24MPa. In this embodiment, the preferred first pressure is 20MPa.

[0101] In step S2023 , the drying chamber 1 is maintained at the first temperature and the first pressure for a preset time, and the pressure drop rate of the drying chamber 1 in multiple time periods within the preset time is obtained.

[0102] When the drying chamber 1 realizes the first temperature and the first pressure for multiple times, the duration is different. For example, after three steps S2021 and S2022, three air intake operations are performed. The preset duration in this step is set to 2h, 4h, 6h or 1h, 2h, 3h, respectively. In this embodiment, 2h, 4h, 6h are preferred to complete three air intake pressure maintenance processes. During the pressure maintenance process, the value of the first pressure detection structure 8 in the drying chamber 1 is observed, and the time and specific pressure value are recorded every 30 minutes. The Pt curve of the pressure change over time is plotted accordingly to calculate the pressure drop rate.

[0103] Step S2024: compare the obtained multiple pressure drop rates with the preset pressure drop rates respectively.

[0104] In this embodiment, the preset pressure drop rate allowed by the drying chamber 1 is set to 3×10 -3 Pa / min, and compare the measured pressure drop rate at different times with the preset pressure drop rate to determine whether the pressure maintenance is successful and whether the drying chamber 1 can remain stable under high temperature and high pressure.

[0105] Step S2025 : When the obtained pressure drop rate is greater than the preset pressure drop rate, the air tightness test of the drying chamber 1 is performed again.

[0106] During the pressure holding test, if the pressure drop rate in any period of the Pt curve exceeds the preset pressure drop rate, the pressure holding fails, and the air tightness test of the drying chamber 1 needs to be performed again, that is, helium is used for leak detection.

[0107] In one embodiment, in the above-mentioned step of performing a pressure-maintaining test on the drying chamber 1, step S2022 gradually introduces a second test gas into the drying chamber 1 so that the drying chamber 1 has a first pressure, including: controlling the gas flow rate of the second test gas to gradually fill the drying chamber 1 in a gradient increasing manner.

[0108] Specifically, open the second gas source 4, along Figure 8 When the second test gas, i.e., nitrogen, is slowly introduced into the path indicated by the black bold arrow, the initial flow rate of nitrogen is 100 mL / min, which is set to 500 mL / min after 5 minutes and to 2 L / min after 10 minutes to avoid over-flow. Finally, nitrogen is purged for 20 minutes to complete the replacement of the air in the system. During the purging process, the nitrogen flow rate should be maintained in the range of 2 to 10 L / min, so that the pressure in the drying chamber 1 and related pipelines reaches 1.1 to 1.5 times the pipeline use pressure, i.e., 17.6 MPa to 24 MPa, and then the second gas source 4 is closed. In this embodiment, it is preferred to make the pressure in the drying chamber 1 and related pipelines reach 20 MPa.

[0109] In this embodiment, reference Fig. 9 and Fig.10 , Fig. 9 The flowchart of the aging process for the drying chamber 1 is shown in FIG. The aging process for the drying chamber 1 includes the following steps:

[0110] Step S2031 , introducing a third test gas into the drying chamber 1 for gas purge.

[0111] First, keep the drying chamber 1 completely sealed under normal pressure and lock the door panel, so that the drying chamber 1 forms a closed space. Open the valves on the third gas source 5, the third gas inlet pipeline 12 and the gas-liquid delivery pipeline 9, and the third test gas flows along the Fig.10 The path indicated by the black arrow is injected into the drying chamber 1 through the third air intake pipe 12, the air intake pipe, the first throttling assembly 14 and the filter 15 on the air intake pipe, and the second nozzle 27. During the air intake process, the flow rate in the drying chamber 1 is controlled at 10L / min to 30L / min, preferably 20L / min. The large flow rate makes the flow in the drying chamber 1 enter a turbulent state, forming a greater flushing force on the inner wall surface of the drying chamber 1. The high-speed flushing lasts for 10min to 20min to complete the replacement of the air in the system by the third test gas.

[0112] Step S2032 , heating the drying chamber 1 and continuously introducing the third test gas, so that the drying chamber 1 has a second pressure and a second temperature.

[0113] Specifically, after the third test gas replaces the air in the system, the third test gas in the system is heated to a second temperature by the heating structure 6, and the air intake is stopped after the pressure of the drying chamber 1 reaches the second pressure. In this embodiment, the second temperature is 250°C and the second pressure is 16MPa.

[0114] Step S2033 : the drying chamber 1 is kept at the second pressure and the second temperature for a period of time to form a dense protective layer on the inner wall surface of the drying chamber 1 .

[0115] Specifically, after the third gas source 5 is turned off, heating and insulation are continued, and the temperature fluctuation is limited to the range of 200°C to 300°C, preferably 250°C in this embodiment, and the continuous heating and insulation time is set to 4h to 8h, preferably 6h in this embodiment, so as to form a dense oxide protective layer in the drying chamber 1 and related pipelines to prevent metal impurities from precipitating and affecting the supercritical drying process.

[0116] In one embodiment, before the third test gas is introduced into the drying chamber 1 for gas purge in step S2031, the drying chamber 1 is also preheated by the heating structure 6. Specifically, the preheating makes the drying chamber 1 reach 90°C before purge.

[0117] In one embodiment, in the above-mentioned step of performing an aging process on the drying chamber 1, before the third test gas is introduced into the drying chamber 1 for gas blowing in step S2031, specifically before preheating, it also includes: in the drying chamber 1 where no dense protective layer is formed, a first wafer placed in the drying chamber 1 is subjected to surface infiltration treatment by a third gas source 5; a first scanning image of the surface of the first wafer after the infiltration treatment, and a first metal particle density value of the surface of the first wafer are obtained.

[0118] After forming a dense protective layer on the inner wall surface of the drying chamber 1 in step S2032, the method also includes: in the drying chamber 1 where the dense protective layer is formed, performing surface wetting treatment on a second wafer placed in the drying chamber 1 through a third gas source 5; obtaining a second scanning image of the surface of the second wafer after the wetting treatment, and a second metal particle density value of the surface of the second wafer; comparing the obtained second scanning image with the first scanning image to obtain the degree of improvement in the cleanliness of the drying chamber 1, and when the second metal particle density value is less than the target metal particle density value, the drying chamber 1 after the aging process treatment is used for a drying process.

[0119] Exemplarily, before the above-mentioned aging process step S2031, a plurality of first wafers, such as 5 wafers or 10 wafers, are purged and wetted with the third test gas in the drying chamber 1. This process lasts for 5 to 15 minutes, preferably 10 minutes in this embodiment. After that, a total reflection X-ray fluorescence spectrometer (abbreviated as TXRF) is used to test the density of metal ion contaminants on the surfaces of the plurality of first wafers, that is, the density of the first metal particles (the detection limit of TXRF is 1E9 to 1E12 atoms / cm 2 ), obtain the surface scan data of the elements on the surface of the first wafer, draw a pseudo-color map after processing the data, and then obtain the information on the quantity and regional distribution of metal pollutants such as Fe and Cr on the surface of the first wafer, and seal the first wafer after testing. After the above-mentioned aging process treatment step S2032, repeat the above steps again, use the third test gas from the third gas source 5 to perform infiltration and TXRF testing on multiple second wafers arranged in the drying chamber 1 after aging treatment, and compare with the test results of the first wafer before the above-mentioned aging to verify the improvement of the cleanliness of the drying chamber 1 and the pipeline by the aging process. If the measured density of metal particles such as Fe, Cr, Ni, Mo, Al, Nb, V, Cu, Ti, etc. is less than the target metal particle density, then the cleanliness of the supercritical gas after aging in the drying chamber 1 meets the standard. The target metal particle density in this embodiment is 1E10atoms / cm 2 .

[0120] In this embodiment, by comparing the metal particle densities on the surfaces of different wafers that have been treated with the third test gas and those that have not been treated with the third test gas, it is verified whether the cleanliness of the supercritical gas drying in the drying chamber 1 after aging meets the standard.

[0121] The pressure-maintaining aging test method of this embodiment can realize the air-tightness test, pressure-maintaining test and aging process treatment of the drying system. When using supercritical carbon dioxide drying treatment, the process temperature and pressure are guaranteed, and the precipitation of metal impurities is guaranteed to be below the index. Among them, the air-tightness test of the drying chamber 1 is carried out by forming an air pressure difference between the drying chamber 1 to be tested and its external space, and using the pressure difference to accurately obtain the gas leakage rate of the drying chamber 1, and compare it with the preset leakage rate allowed by the drying chamber 1, and finally verify the air-tightness of the drying chamber 1 to ensure the reliability of the drying chamber 1 during the drying process; the pressure-maintaining test of the drying chamber 1 is carried out by heating the interior of the drying chamber 1 through the heating structure 6 to form a high-temperature environment required for the supercritical carbon dioxide drying process in the drying chamber 1, and the second gas source 4 introduces a second test gas into the drying chamber 1 to form a high-pressure environment in the drying chamber 1. After a period of time, the pressure drop rate is compared with the target pressure drop rate set for the pressure holding test to determine whether the drying chamber 1 is stable under a long-term high temperature and high pressure state, so as to complete the pressure holding test; during the aging process of the drying chamber 1, the third test gas is introduced into the drying chamber 1 through the third gas source 5 for purging, and then the third test gas and the heating structure 6 act simultaneously to form a high pressure and high temperature environment in the drying chamber 1, and the aging process is completed by heat preservation for a certain period of time, and at the same time, a dense protective layer is formed on the inner wall surface, which effectively prevents the inner wall surface of the drying chamber 1 from being corroded during the drying process and avoids the precipitation of metal pollutants during the drying process.

[0122] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0123] In addition, in order to form the same structure, those skilled in the art may also design a method that is not completely the same as the method described above. In addition, although the embodiments are described above respectively, this does not mean that the measures in the embodiments cannot be used in combination advantageously.

[0124] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A pressure-maintaining aging test system, characterized in that: include: Drying chamber; A first sealing structure, which is disposed outside the drying chamber; A first detection space is provided between the first sealing structure and the drying chamber; A first gas source connected to the drying chamber and the first sealing structure; the first gas source is suitable for introducing a first test gas into the drying chamber or the first detection space; A gas leak detection assembly, adapted to detect the target gas content in the drying chamber and / or the first detection space; a second gas source connected to the drying chamber, the second gas source being suitable for introducing a second test gas into the drying chamber; a third gas source connected to the drying chamber, the third gas source being adapted to introduce a third test gas into the drying chamber and forming a dense protective layer on an inner wall surface of the drying chamber; A heating structure, a first temperature detection structure and a first pressure detection structure disposed in the drying chamber; And a third pressure detection structure is arranged in the first sealing structure.

2. The pressure-maintaining aging test system according to claim 1, characterized in that: The first gas source is a helium gas source, the second gas source is a nitrogen gas source, and the third gas source is a carbon dioxide gas source.

3. The pressure-maintaining aging test system according to claim 2, characterized in that: Also includes: A gas-liquid delivery pipeline is provided between the first gas source, the second gas source, the third gas source and the drying chamber, the gas-liquid delivery pipeline comprises a first inlet, a second inlet, a third inlet and a first outlet, and the first outlet is connected to the drying chamber; a first air inlet pipeline, one end of which is connected to the first air source and the other end of which is suitable for being connected to the first inlet of the gas-liquid delivery pipeline; a second air inlet pipeline, one end of which is connected to the second air source and the other end of which is suitable for being connected to the second inlet; A third air inlet pipeline, one end of which is connected to the third air source and the other end of which is suitable for being connected to the third inlet; A fourth air inlet pipeline has one end connected to the first air source and the other end connected to the first sealing structure to communicate with the first detection space.

4. The pressure-maintaining aging test system according to claim 3, characterized in that: The gas-liquid transport pipeline is provided with a first throttling component and a filter, wherein the first throttling component is suitable for regulating the gas flow in the gas-liquid transport pipeline, and the filter is suitable for filtering impurities in the gas passing through the gas-liquid transport pipeline.

5. The pressure-maintaining aging test system according to claim 4, characterized in that: Also includes: A second sealing structure, which is covered on the gas-liquid delivery pipeline to form a second detection space outside the gas-liquid delivery pipeline; The second detection space of the second sealing structure is suitable for being connected to the first gas source.

6. The pressure-maintaining aging test system according to claim 5, characterized in that: The gas leak detection assembly comprises: A first gas leak detection structure is arranged in the drying chamber; The second gas leak detection structure is suitable for being connected to the first sealing structure and the second sealing structure respectively. The second gas leak detection structure comprises: a leak detector, a first suction gun and a second suction gun. One end of the first suction gun is connected to the leak detector, and the other end is connected to the first detection space; one end of the second suction gun is connected to the leak detector, and the other end is connected to the second detection space.

7. The pressure-maintaining aging test system according to claim 6, characterized in that: Also includes: A second temperature detection structure is arranged on the gas-liquid delivery pipeline; The second pressure detection structure is arranged on the second sealing structure to detect the air pressure of the second detection space.

8. A pressure-maintaining aging test method, characterized in that: include: The air tightness test of the drying chamber comprises: introducing a first test gas into the drying chamber or a first sealing structure covered outside the drying chamber through a first gas source, so as to form an air pressure difference between the drying chamber and the first sealing structure outside the drying chamber; obtaining a leakage rate of the first test gas in the drying chamber with a lower air pressure or in a first detection space of the first sealing structure with a lower air pressure; comparing the obtained leakage rate of the first test gas with a preset leakage rate; and, when the leakage rate of the first test gas is higher than the preset leakage rate, detecting the leakage rate of the first test gas at each connection position on the drying chamber to obtain the leakage position of the drying chamber; The pressure-maintaining test of the drying chamber comprises: heating the drying chamber by a heating structure so that the drying chamber has a first temperature; gradually introducing a second test gas into the drying chamber so that the drying chamber has a first pressure; the drying chamber is kept at the first temperature and the first pressure for a preset time, and the pressure drop rate of the drying chamber in multiple time periods within the preset time is obtained; the multiple pressure drop rates obtained are respectively compared with the preset pressure drop rate; when the obtained pressure drop rate is greater than the preset pressure drop rate, the airtightness test of the drying chamber is performed again; The drying chamber is subjected to an aging process, comprising: introducing a third test gas into the drying chamber for gas blowing; heating the drying chamber and continuously introducing the third test gas so that the drying chamber has a second pressure and a second temperature; the drying chamber is maintained at the second pressure and the second temperature for a period of time to form a dense protective layer on the inner wall surface of the drying chamber.

9. The pressure-maintaining aging test method according to claim 8, characterized in that: In the step of performing a pressure-maintaining test on the drying chamber, gradually introducing a second test gas into the drying chamber so that the drying chamber has a first pressure includes: controlling the gas flow rate of the second test gas to gradually fill the drying chamber in a gradient increasing manner.

10. The pressure-maintaining aging test method according to claim 8, characterized in that: In the step of performing an aging process on the drying chamber, Before the third test gas is introduced into the drying chamber so that the drying chamber has a second pressure, the method further includes: in the drying chamber where no dense protective layer is formed, performing a surface wetting treatment on a first wafer placed in the drying chamber through a third gas source; obtaining a first scan image of the surface of the first wafer after the wetting treatment, and a first metal particle density value on the surface of the first wafer; After a dense protective layer is formed on the inner wall surface of the drying chamber, the method further includes: in the drying chamber where the dense protective layer is formed, performing surface infiltration treatment on a second wafer placed in the drying chamber by a third gas source; obtaining a second scanning image of the surface of the second wafer after the infiltration treatment, and a second metal particle density value of the surface of the second wafer; comparing the obtained second scanning image with the first scanning image to obtain the degree of improvement in the cleanliness of the drying chamber, and when the second metal particle density value is less than the target metal particle density value, the drying chamber after the aging process treatment is used for a drying process.

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