Passivation method of silane container

Abstract

The invention discloses a passivation method of a silane container, and relates to the technical field of semiconductor manufacturing. The method comprises the following steps: replacing a silane container with nitrogen for a plurality of times; replacing the silane container with hydrogen or helium for a plurality of times; and replacing the silane container with silane gas for a plurality of times so as to passivate the silane container. According to the embodiment of the invention, not only can the passivation of the silane container be quickly realized, but also the interior of the silane tank car can be ensured to be absolutely clean and a passivation film is formed, so that the high-purity silane gas is ensured not to be polluted after being filled into the silane container.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor manufacturing, and in particular to a passivation method for a silane container. Background Art

[0002] Silane tank truck passivation research refers to a series of operations such as drying, replacement, vacuuming, passivation, and testing before the first filling of a new silane tank truck or a repaired tank truck, so as to achieve an absolutely clean environment inside the silane tank truck and ensure that the high-purity silane gas is not contaminated after being filled into the tank truck.

[0003] However, the prior art cannot ensure that the silane tank truck is fully passivated, resulting in an inability to ensure that the high-purity silane gas is not contaminated after being filled into the tank truck. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a passivation method for a silane container to solve the technical problem of being unable to ensure that high-purity silane gas is not contaminated after being filled into the silane container.

[0005] To achieve the above object, a passivation method for a silane container is provided according to an embodiment of the present invention, comprising:

[0006] The silane container was replaced several times with nitrogen;

[0007] Replacing the silane container several times with hydrogen or helium;

[0008] The silane container is replaced with silane gas several times to passivate the silane container.

[0009] Optionally, the silane container is purged with nitrogen several times, including:

[0010] The silane container is replaced with nitrogen for 5 to 10 times until the water content and oxygen content in the silane container meet the preset requirements.

[0011] Optionally, during each nitrogen replacement process, nitrogen is introduced into the silane container until the pressure in the silane container is 500-800 kPa, and then the silane container is deflated until the pressure in the silane container is normal pressure, and then the next nitrogen replacement is continued.

[0012] Optionally, during the last nitrogen replacement, when the silane container is vented to normal pressure, the silane container is evacuated until the pressure in the silane container is -100 to -50 kPa.

[0013] Optionally, the preset conditions include a dew point of -30 to -40°C and an oxygen content of 0 to 0.1%.

[0014] Optionally, the silane container is replaced several times with hydrogen or helium, including:

[0015] Use hydrogen or helium to replace the silane container 1-10 times;

[0016] In each replacement process, hydrogen or helium is introduced into the silane container to break the vacuum, so that the pressure in the silane container is above normal pressure, and then the silane container is evacuated after standing for 0.2-1 hour until the pressure in the silane container is -100 to -50 kPa.

[0017] Optionally, the silane container is replaced several times with silane gas to passivate the silane container, comprising:

[0018] Passing silane gas into the silane container until the pressure in the silane container is 200-400 kPa, and leaving it to stand for 2-10 days;

[0019] Every 1 to 2 days, the growth amount of the oxygen silane content in the silane container is detected. If the growth amount of the oxygen silane content meets the preset condition, the silane container is deflated until the pressure in the silane container is normal pressure, and then the silane container is evacuated until the pressure in the silane container is -100 to -80 kPa;

[0020] The silane container is replaced with silane gas 2 to 10 times.

[0021] Optionally, the silane container is replaced 2 to 10 times with silane gas, comprising:

[0022] During each silane gas replacement process, silane gas is introduced into the silane container until the pressure in the silane container is 200-400 kPa, and then the silane container is deflated until the pressure in the silane container is normal pressure, and then the next silane gas replacement is continued.

[0023] Optionally, the increase in the oxygen silane content is calculated using the following formula:

[0024] The oxygen silane content of the latter test minus the oxygen silane content of the previous test.

[0025] Optionally, the preset condition includes that the increase in the oxygen silane content is less than 1 ppm.

[0026] One embodiment of the above invention has the following advantages or beneficial effects: the embodiment of the present invention can not only quickly realize the passivation of the silane container, but also ensure that the interior of the silane tank truck is absolutely clean and forms a passivation film, thereby ensuring that the high-purity silane gas is not contaminated after being filled into the silane container.

[0027] The further effects of the above-mentioned non-conventional optional manner will be described below in conjunction with the specific implementation manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0029] Figure 1 1 is a schematic diagram of the main process of the passivation method of the silane container according to an embodiment of the present invention;

[0030] Figure 2 is a schematic diagram of a silane tank truck passivation system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following is a description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0032] In order to solve the technical problems existing in the prior art, an embodiment of the present invention provides a passivation method for a silane container. The method is used to treat the silane container using this passivation process before the first silane gas filling to ensure that the interior of the silane container is absolutely clean and a passivation film is formed, thereby solving the technical problem of high-purity silane gas being contaminated by storage and transportation equipment during storage and transportation after being filled into the silane container.

[0033] Figure 1 Schematic diagram of the main process of the passivation method of the silane container according to an embodiment of the present invention. Figure 1 As shown, the passivation method of the silane container may include:

[0034] Step 101, replacing the silane container with nitrogen several times;

[0035] Step 102, replacing the silane container several times with hydrogen or helium;

[0036] Step 103, using silane gas to replace the silane container several times to passivate the silane container.

[0037] The embodiment of the present invention can ensure that the interior of the silane container is absolutely clean and a passivation film is formed, and the passivated silane container can store and transport silane gas cleanly for a long time without the need for secondary passivation.

[0038] Optionally, step 101 may include: replacing the silane container with nitrogen for 5 to 10 times until the water content and oxygen content in the silane container meet the preset requirements. Optionally, during each nitrogen replacement process, nitrogen is introduced into the silane container until the pressure in the silane container is 500 to 800 kpa, and then the silane container is deflated until the pressure in the silane container is normal pressure, and then the next nitrogen replacement is continued. The purpose of replacing the silane container with nitrogen is to take away the water vapor and oxygen in the silane container. It should be noted that oxygen and the intermediate replacement gas (such as hydrogen) will form an explosive mixed gas, and oxygen and silane gas will undergo a combustion reaction; residual water vapor will react with silane gas to generate silicon dioxide powder, causing container pollution and product pollution. Therefore, the embodiment of the present invention removes oxygen and water vapor in the container in step 101, which can not only ensure safety, but also prevent the silane container from being contaminated.

[0039] Wherein, in step 101, the number of times of replacing the silane container with nitrogen is typically but not limitedly preferably 5 times, 6 times, 7 times, 8 times, 9 times or 10 times. In these embodiments, it is possible to take away the water vapor and oxygen in the silane container as much as possible, and it is also possible to shorten the passivation cycle and reduce the passivation workload. Optionally, in step 101, during each nitrogen replacement process, nitrogen is introduced into the silane container until the pressure in the silane container is 550kpa. Optionally, in step 101, during each nitrogen replacement process, nitrogen is introduced into the silane container until the pressure in the silane container is 620kpa. Optionally, in step 101, during each nitrogen replacement process, nitrogen is introduced into the silane container until the pressure in the silane container is 780kpa. Optionally, in step 101, during each nitrogen replacement process, nitrogen is introduced into the silane container until the pressure in the silane container is 800kpa.

[0040] Optionally, during the last nitrogen replacement, when the silane container is vented to normal pressure, the silane container is evacuated until the pressure in the silane container is -100 to -50 kPa, so that the oxygen and water vapor in the container can be removed, which not only ensures safety but also prevents the silane container from being contaminated. Optionally, during the last nitrogen replacement, when the silane container is vented to normal pressure, the silane container is evacuated until the pressure in the silane container is -100 kPa. Optionally, during the last nitrogen replacement, when the silane container is vented to normal pressure, the silane container is evacuated until the pressure in the silane container is -92 kPa. Optionally, during the last nitrogen replacement, when the silane container is vented to normal pressure, the silane container is evacuated until the pressure in the silane container is -88 kPa. Optionally, during the last nitrogen replacement, when the silane container is vented to normal pressure, the silane container is evacuated until the pressure in the silane container is -75 kPa. Optionally, during the last nitrogen replacement, when the silane container is vented to normal pressure, the silane container is evacuated until the pressure in the silane container is -65 kPa. Optionally, during the last nitrogen replacement, when the silane container is vented to normal pressure, the silane container is evacuated until the pressure in the silane container is -50 kPa.

[0041] Optionally, the preset conditions include a dew point of minus 30-40°C and an oxygen content of 0-0.1%, which can ensure the safety and cleanliness of the replacement, and the replacement process will not take too long.

[0042] Optionally, step 102 may include: replacing the silane container with hydrogen or helium 1-10 times; wherein, during each replacement process, hydrogen or helium is introduced into the silane container to break the vacuum, so that the pressure in the silane container is above normal pressure, and then the silane container is evacuated after standing for 0.2-1 hour until the pressure in the silane container is -100 to -50kPa. The purpose of step 102 is to break the vacuum with hydrogen or helium, stand for 0.2-1 hour, so that the hydrogen or helium is evenly distributed in the container, and then replace the nitrogen remaining in the silane container by vacuuming, so that the nitrogen in the silane container is replaced more thoroughly to prevent nitrogen from contaminating the silane container. Among the qualified indicators of silane gas products, the nitrogen indicator is much lower than the hydrogen indicator.

[0043] It should be noted that if hydrogen is used to replace the silane container, step 101 must be performed. If helium is used to replace the silane container, step 101 may not be performed, but this will increase the number of helium replacements, resulting in increased replacement costs.

[0044] The passivation method of the silane container provided in the embodiment of the present invention is not a simple replacement operation. The key lies in multiple rapid vacuuming and breaking of the vacuum in the silane container to ensure that the passivation is quickly achieved. Moreover, the passivation time of the silane container depends on the precise control of the vacuum value. A lower parameter is conducive to the qualified passivation of the tank truck, but it will reduce the passivation rate of the tank truck, and vice versa. Therefore, the selection of the vacuum value for vacuuming is crucial.

[0045] Optionally, step 103 may include: passing silane gas into the silane container until the pressure in the silane container is 200-400 kPa, and standing for 2-10 days; detecting the increase in the oxygen silane content in the silane container every 1-2 days, and if the increase in the oxygen silane content meets a preset condition, deflating the silane container until the pressure in the silane container is normal pressure, and then evacuating the silane container until the pressure in the silane container is -100--80 kPa; and replacing the silane container with silane gas 2-10 times.

[0046] It should be noted that after the silane gas is passed into the silane container, it is first allowed to stand for 2 to 10 days, and then the growth of the oxygen silane content in the silane container is detected every 1 to 2 days. If the test result meets the preset conditions, the standing is terminated. If the preset conditions are not met, it is continued to stand for 1 to 2 days, and then the growth of the oxygen silane content in the silane container is detected until the change meets the preset conditions. According to the chemical reaction between the silane gas and the container, if there is still a reaction, a certain amount of oxygen silane will be generated within 24 hours. Therefore, the growth of the oxygen silane content is used to judge whether the container has completed passivation. If the oxygen silane content increases very little, it means that the metal surface of the container no longer reacts with the silane gas, and it is judged that the passivation film on the surface of the container has been formed, and no other reactants will be produced in the later stage, and the silane gas can be stored and transported cleanly.

[0047] Optionally, the silane container is replaced with silane gas 2 to 10 times, including: during each silane gas replacement process, silane gas is introduced into the silane container until the pressure in the silane container is 200 to 400 kPa, and then the silane container is deflated until the pressure in the silane container is normal pressure, and then the next silane gas replacement is continued.

[0048] Optionally, the increase in the oxygen silane content is calculated using the following formula:

[0049] The oxygen silane content of the latter test minus the oxygen silane content of the previous test.

[0050] Optionally, the preset condition includes an increase in the oxygen silane content being less than 1 ppm.

[0051] It should be noted that if the pressure is controlled at a high level, the pressure increase and pressure release time will be prolonged, and if the pressure is controlled at a low level, the replacement effect will be affected. The embodiment of the present invention controls the pressure at 200-400 kPa, which can achieve both rapid passivation and passivation effect. In addition, the longer the passivation time, the denser and more complete the passivation film on the surface of the container, but the longer the passivation time, the longer the overall passivation cycle will be. The method provided by the embodiment of the present invention can achieve both rapid passivation and passivation effect.

[0052] The purpose of the embodiment of the present invention is to solve the technical problem that high-purity silane gas is contaminated by storage and transportation equipment during storage and transportation. The passivation method of the silane container provided by the embodiment of the present invention is used for the silane tank truck to use the passivation process before the first silane gas filling to ensure that the interior of the silane tank truck is absolutely clean and a passivation film is formed.

[0053] To help understand the solution of the present invention, take a silane tank car as an example. Figure 2 As shown, several specific silane tank car passivation processes are given below.

[0054] Example 1

[0055] Step 1), replace the silane tank truck with nitrogen 6 times, and use a detection system to detect the dew point and oxygen content in the silane tank truck until the water content and oxygen content in the silane tank truck meet the preset requirements. The preset conditions include a dew point of minus 30 to 40°C and an oxygen content of 0 to 0.1%.

[0056] During each nitrogen replacement process, nitrogen is introduced into the silane tank truck until the pressure inside the silane tank truck is 550 kPa, and then the silane tank truck is deflated using a venting system until the pressure inside the silane tank truck is normal pressure, and then the next nitrogen replacement is continued.

[0057] During the last nitrogen replacement, when the silane tank truck is vented to normal pressure, a vacuum pump system is used to evacuate the silane tank truck until the pressure inside the silane tank truck is -80 kPa.

[0058] Step 2), replace the silane tank truck 3 times with hydrogen or helium.

[0059] In each replacement process, hydrogen or helium is introduced into the silane tank truck to break the vacuum, so that the pressure in the silane tank truck is above normal pressure, and then the silane tank truck is vacuumed after standing for 0.3 hours until the pressure in the silane tank truck is -100kpa.

[0060] Step 3), silane gas is introduced into the silane tank truck until the pressure in the silane tank truck reaches 200 kPa, and then the silane tank truck is left to stand for 8 days.

[0061] Step 4), every 2 days, the change in the oxygen silane content in the silane tank truck is detected. If the change meets the preset conditions, the silane tank truck is deflated until the pressure in the silane tank truck is normal pressure, and then the silane tank truck is vacuumed until the pressure in the silane tank truck is -80 kPa. The preset conditions include that the increase in the oxygen silane content is less than 1 ppm.

[0062] Step 5), using silane gas to replace the silane tank truck 4 times.

[0063] In which, during each silane gas replacement process, silane gas is introduced into the silane tank truck until the pressure in the silane tank truck is 350kPa, and then the silane tank truck is deflated until the pressure in the silane tank truck is normal pressure, and then the next silane gas replacement is continued.

[0064] Example 2

[0065] The difference between the preparation method of the embodiment 1 and the preparation method of the embodiment 1 is that in step 1), the silane tank truck is replaced with nitrogen for 5 times.

[0066] Example 3

[0067] The difference between the preparation method of the embodiment 1 and the preparation method of the embodiment 1 is that in step 1), the silane tank truck is replaced with nitrogen for 7 times.

[0068] Example 4

[0069] The difference between the preparation method of the embodiment 1 and the preparation method of the embodiment 1 is that in step 1), nitrogen is used to replace the silane tank truck 8 times.

[0070] Example 5

[0071] The difference between the preparation method of the embodiment 1 and the preparation method of the embodiment 1 is that in step 1), during each nitrogen replacement process, nitrogen is introduced into the silane tank truck until the pressure in the silane tank truck reaches 620 kPa.

[0072] Example 6

[0073] The difference between the preparation method of the embodiment 1 and the preparation method of the embodiment 1 is that in step 1), during each nitrogen replacement process, nitrogen is introduced into the silane tank truck until the pressure in the silane tank truck reaches 680 kPa.

[0074] Example 7

[0075] The difference between the preparation method of the present invention and that of Example 1 is that in step 1), during each nitrogen replacement process, nitrogen is introduced into the silane tank truck until the pressure in the silane tank truck reaches 758 kPa.

[0076] Example 8

[0077] The difference between the preparation method of the present invention and that of Example 1 is that in step 1), during each nitrogen replacement process, nitrogen is introduced into the silane tank truck until the pressure in the silane tank truck reaches 780 kPa.

[0078] Example 9

[0079] The difference between the preparation method of the embodiment 1 and the preparation method of the embodiment 1 is that in step 1), during the last nitrogen replacement, when the silane tank truck is vented to normal pressure, the silane tank truck is evacuated until the pressure inside the silane tank truck is -100 kPa.

[0080] Example 10

[0081] The difference between the preparation method of the embodiment 1 and the preparation method of the embodiment 1 is that in step 1), during the last nitrogen replacement, when the silane tank truck is vented to normal pressure, the silane tank truck is evacuated until the pressure inside the silane tank truck is -90 kPa.

[0082] Embodiment 11

[0083] The difference between the preparation method of the embodiment 1 and the preparation method of the embodiment 1 is that in step 1), during the last nitrogen replacement, when the silane tank truck is vented to normal pressure, the silane tank truck is evacuated until the pressure inside the silane tank truck is -55 kPa.

[0084] Example 12

[0085] The difference between the preparation method of the present invention and that of Example 1 is that in step 2), hydrogen or helium is used to replace the silane tank truck 8 times. During each replacement process, hydrogen or helium is introduced into the silane tank truck to break the vacuum, so that the pressure in the silane tank truck is above normal pressure, and then the silane tank truck is vacuumed after standing for 0.5 hours until the pressure in the silane tank truck is -100 to -50 kPa.

[0086] Embodiment 13

[0087] The difference between the preparation method of the present invention and that of Example 1 is that in step 2), hydrogen or helium is used to replace the silane tank truck 5 times. During each replacement process, hydrogen or helium is introduced into the silane tank truck to break the vacuum, so that the pressure in the silane tank truck is above normal pressure, and then the silane tank truck is vacuumed after standing for 0.4 hours until the pressure in the silane tank truck is -80 kPa.

[0088] Embodiment 14

[0089] The difference between the preparation method of the present invention and that of Example 1 is that: in step 2), hydrogen or helium is used to replace the silane tank truck 4 times. During each replacement process, hydrogen or helium is introduced into the silane tank truck to break the vacuum, so that the pressure in the silane tank truck is above normal pressure, and then the silane tank truck is vacuumed after standing for 0.6 hours until the pressure in the silane tank truck is -60 kPa.

[0090] Embodiment 15

[0091] The difference between the preparation method of the present invention and that of Example 1 is that: in step 2), hydrogen or helium is used to replace the silane tank truck 10 times. During each replacement process, hydrogen or helium is introduced into the silane tank truck to break the vacuum, so that the pressure in the silane tank truck is above normal pressure, and then the silane tank truck is vacuumed after standing for 0.8 hours until the pressure in the silane tank truck is -100 kPa.

[0092] Example 16

[0093] The difference between the preparation method of the embodiment 1 and the preparation method of the embodiment 1 is that in step 3), silane gas is introduced into the silane tank truck until the pressure in the silane tank truck reaches 250 kPa, and the silane tank truck is left to stand for 9 days.

[0094] Embodiment 17

[0095] The difference between the preparation method of the embodiment 1 and the preparation method of the embodiment 1 is that in step 3), silane gas is introduced into the silane tank truck until the pressure in the silane tank truck reaches 400 kPa, and the silane tank truck is left to stand for 7 days.

[0096] Embodiment 18

[0097] The difference between the preparation method of the embodiment 1 and the preparation method of the embodiment 1 is that in step 3), silane gas is introduced into the silane tank truck until the pressure in the silane tank truck reaches 320 kPa, and the silane tank truck is left to stand for 8.5 days.

[0098] Embodiment 19

[0099] The difference between the preparation method of the present invention and that of Example 1 is that in step 4), the change in the oxygen silane content in the silane tank truck is detected every 2 days. If the change meets the preset conditions, the silane tank truck is deflated until the pressure in the silane tank truck is at normal pressure, and then the silane tank truck is evacuated until the pressure in the silane tank truck is -100 kPa.

[0100] Embodiment 20

[0101] The difference between the preparation method of the present invention and that of Example 1 is that in step 4), the change in the oxygen silane content in the silane tank truck is detected every 1.5 days. If the change meets the preset conditions, the silane tank truck is deflated until the pressure in the silane tank truck is at normal pressure, and then the silane tank truck is evacuated until the pressure in the silane tank truck is -90 kPa.

[0102] Embodiment 21

[0103] The difference between the preparation method of the present invention and that of Example 1 is that: in step 5), the silane tank truck is replaced with silane gas three times. During each silane gas replacement process, silane gas is introduced into the silane tank truck until the pressure in the silane tank truck is 400 kPa, and then the silane tank truck is deflated until the pressure in the silane tank truck is normal pressure, and then the next silane gas replacement is continued.

[0104] Embodiment 22

[0105] The difference between the preparation method of the present invention and that of Example 1 is that in step 5), the silane tank truck is replaced with silane gas 6 times. During each silane gas replacement process, silane gas is introduced into the silane tank truck until the pressure in the silane tank truck reaches 310 kPa, and then the silane tank truck is deflated until the pressure in the silane tank truck reaches normal pressure, and then the next silane gas replacement is continued.

[0106] Embodiment 23

[0107] The difference between the preparation method of the present invention and that of Example 1 is that in step 5), the silane tank truck is replaced with silane gas 8 times. During each silane gas replacement process, silane gas is introduced into the silane tank truck until the pressure in the silane tank truck reaches 215 kPa, and then the silane tank truck is deflated until the pressure in the silane tank truck reaches normal pressure, and then the next silane gas replacement is continued.

[0108] Embodiment 24

[0109] The difference between the preparation method of the present invention and that of Example 1 is that in step 5), the silane tank truck is replaced with silane gas 10 times. During each silane gas replacement process, silane gas is introduced into the silane tank truck until the pressure in the silane tank truck is 400 kPa, and then the silane tank truck is deflated until the pressure in the silane tank truck is normal pressure, and then the next silane gas replacement is continued.

[0110] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may occur depending on design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A passivation method for a silane container, characterized in that: The following steps are involved: The silane container was replaced several times with nitrogen; Replacing the silane container several times with hydrogen or helium; The silane container is replaced with silane gas several times to passivate the silane container.

2. The method according to claim 1, characterized in that The silane container was purged with nitrogen several times, including: The silane container is replaced with nitrogen for 5 to 10 times until the water content and oxygen content in the silane container meet the preset requirements.

3. The method according to claim 2, characterized in that During each nitrogen replacement process, nitrogen is introduced into the silane container until the pressure in the silane container is 500-800 kPa, and then the silane container is deflated until the pressure in the silane container is normal pressure, and then the next nitrogen replacement is continued.

4. The method according to claim 2, characterized in that: During the last nitrogen replacement, when the silane container is vented to normal pressure, the silane container is evacuated until the pressure in the silane container is -100 to -50 kPa.

5. The method according to claim 2, characterized in that: The preset conditions include a dew point of -30 to -40°C and an oxygen content of 0 to 0.1%.

6. The method according to claim 1, characterized in that The silane container is replaced several times with hydrogen or helium, including: Use hydrogen or helium to replace the silane container 1-10 times; In each replacement process, hydrogen or helium is introduced into the silane container to break the vacuum, so that the pressure in the silane container is above normal pressure, and then the silane container is evacuated after standing for 0.2-1 hour until the pressure in the silane container is -100 to -50 kPa.

7. The method according to claim 1, characterized in that The silane container is replaced several times with silane gas to passivate the silane container, including: Passing silane gas into the silane container until the pressure in the silane container is 200-400 kPa, and leaving it to stand for 2-10 days; Every 1 to 2 days, the growth amount of the oxygen silane content in the silane container is detected. If the growth amount of the oxygen silane content meets the preset condition, the silane container is deflated until the pressure in the silane container is normal pressure, and then the silane container is evacuated until the pressure in the silane container is -100 to -80 kPa; The silane container is replaced with silane gas 2 to 10 times.

8. The method according to claim 7, characterized in that The silane container is replaced 2 to 10 times with silane gas, comprising: During each silane gas replacement process, silane gas is introduced into the silane container until the pressure in the silane container is 200-400 kPa, and then the silane container is deflated until the pressure in the silane container is normal pressure, and then the next silane gas replacement is continued.

9. The method according to claim 7, characterized in that: The growth amount of the oxygen silane content is calculated using the following formula: The oxygen silane content of the latter test minus the oxygen silane content of the previous test.

10. The method according to claim 7, characterized in that The preset condition includes that the increase in the content of oxygen silane is less than 1 ppm.

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