A cleaning method for thin film deposition tool

Abstract

The present invention belongs to the technical field of vacuum deposition equipment maintenance, and relates to a method for cleaning a thin film deposition jig. A cleaning device for the thin film deposition jig is used, and the cleaning device includes a vacuum chamber, a cleaning table, a mechanical pump, a molecular pump, a vacuum valve, a clean gas storage tank, and a dry gas storage tank. A cleaning table is provided in the vacuum chamber, and the cleaning table is used to place the thin film deposition jig to be cleaned. The method includes the steps of placing the thin film deposition jig to be cleaned, evacuating the vacuum chamber, and cleaning the thin film deposition jig. The present invention utilizes the phenomenon of stress between the thin film deposition jig and the attached film. When the vacuum chamber reaches a certain vacuum degree, a clean gas is introduced to achieve the cracking condition of the attached film, and the attached film falls off, thereby achieving the effect of cleaning the thin film deposition jig and avoiding damage and dimensional changes to the thin film deposition jig.

Description

Technical Field

[0001] The invention belongs to the technical field of vacuum deposition equipment maintenance, and in particular relates to a cleaning method for a thin film deposition jig. Background Art

[0002] With the development of science and technology, semiconductor technology has gradually been applied to every corner of the scientific research field, and thin film technology is a vital part of semiconductor technology. Thin film technology is the deposition or preparation of a layer of material with properties completely different from those of the bulk material on the surface of the bulk material. Different thin film materials have different functions and are used in optics, electricity, magnetism, chemistry, mechanics, and thermodynamics. There are many methods for thin film preparation, including physical and chemical methods. In the process of thin film preparation, jigs are mostly used to fix the sample. During the thin film deposition process, thin films will also adhere to the jigs. Different thin film deposition jigs have different requirements. Some require strict dimensions, some require good conductivity, and some require no particles. All of these require the thin film on the thin film deposition jig to be removed.

[0003] Among the current cleaning methods for thin film deposition jigs, commonly used technologies include acid-base cleaning methods, sandblasting processes, etc.

[0004] Existing jig cleaning methods have various limitations. Acid-base cleaning methods will corrode metal thin film deposition jigs when cleaning thin films on thin film deposition jigs, causing corrosion of the thin film deposition jig and deformation of the size of the thin film deposition jig. The processing of corrosion-resistant ceramic jigs is much more difficult than that of metal jigs. Another commonly used method is sandblasting, which uses a sandblasting machine to spray aluminum oxide particles of different sizes onto the thin film deposition jig. This method removes the thin film on the thin film deposition jig while also removing a layer of the material of the thin film deposition jig. Long-term sandblasting cleaning will cause the size of the thin film deposition jig to change or even deform. In addition, for thin film deposition jigs with more complex structures, the sandblasting process cannot thoroughly clean the film layer at the edges and corners, thereby affecting the deposition of the product film. Summary of the Invention

[0005] In order to overcome the shortcomings of cleaning a thin film deposition jig, such as damage and dimensional changes, the present invention provides a cleaning method for a thin film deposition jig.

[0006] A cleaning method for a thin film deposition jig uses a cleaning device for the thin film deposition jig, wherein the cleaning device comprises a vacuum chamber, a cleaning table, a mechanical pump, a molecular pump, a vacuum valve, a clean gas storage tank, and a dry gas storage tank.

[0007] A cleaning platform is provided in the vacuum chamber, and the cleaning platform is used for placing a thin film deposition jig to be cleaned.

[0008] The molecular pump, the clean gas storage tank, and the dry gas storage tank are respectively communicated with the vacuum cavity, and the mechanical pump is respectively communicated with the molecular pump and the vacuum cavity through the vacuum valve.

[0009] The steps include:

[0010] Step 1: Place the thin film deposition fixture to be cleaned

[0011] Open the vacuum chamber of the cleaning device, place the thin film deposition jig to be cleaned on the cleaning table, and close the vacuum chamber.

[0012] Step 2: Evacuate the vacuum chamber

[0013] The first step is to start the cleaning device and turn on the mechanical pump. The mechanical pump begins to evacuate the vacuum chamber until the vacuum degree of the vacuum chamber is constant, and then turn off the mechanical pump.

[0014] The second step is to open the dry gas storage tank and let the dry gas flow into the vacuum chamber. When the pressure of the vacuum chamber 1 reaches 1 atmosphere, the dry gas storage tank is closed and the mechanical pump is turned on.

[0015] The third step is to use a mechanical pump to evacuate the vacuum chamber until the vacuum degree of the vacuum chamber is less than 10 -3 Torr, turn on the molecular pump until the vacuum degree of the vacuum chamber is constant, turn off the molecular pump and the mechanical pump.

[0016] The fourth step is to open the dry gas storage tank and introduce dry gas into the vacuum chamber until the vacuum chamber reaches 1 atmosphere. Then close the dry gas storage tank and start the mechanical pump until the vacuum degree of the vacuum chamber is <10 -3 Torr, turn on the molecular pump until the vacuum degree of the vacuum chamber is 1×10 -6 ~1×10 -7 Torr, turn off the molecular pump, and turn off the mechanical pump.

[0017] Step 3: Cleaning the thin film deposition fixture

[0018] Open the clean gas storage tank and let the clean gas flow into the vacuum chamber until the pressure in the vacuum chamber reaches 1×10 -3 ~1×10 - 5 Torr, maintain a constant gas pressure until the film layer attached to the thin film deposition fixture falls off.

[0019] In the above-mentioned cleaning method for a thin film deposition jig, the cleaning device further includes a vacuum gauge, which is connected to the vacuum cavity and is used to measure the vacuum degree of the vacuum cavity.

[0020] The above-mentioned cleaning method for thin film deposition jigs, the cleaning device also includes two mass flow meters, which are respectively located on the connecting pipelines of the clean gas storage tank, the dry gas storage tank and the vacuum chamber, and are used to measure the mass flow of the clean gas storage tank and the dry gas storage tank.

[0021] In the above-mentioned cleaning method for a thin film deposition tool, the gas stored in the dry gas storage tank is dry nitrogen.

[0022] In the above-mentioned cleaning method for a thin film deposition tool, the gas stored in the dry gas storage tank may also be dry argon.

[0023] In the above-mentioned method for cleaning a thin film deposition jig, the step 3 of cleaning the thin film deposition jig further comprises:

[0024] The time that the vacuum chamber maintains a constant gas pressure is related to the physical properties and thickness of the thin film attached to the thin film deposition jig. When the clean gas is in full contact with the thin film attached to the thin film deposition jig, and the stress generated between the thin film deposition jig and the attached film reaches the cracking stress, the attached film falls off.

[0025] In the above-mentioned cleaning method for a thin film deposition jig, the cleaning gas stored in the cleaning gas storage tank is water vapor.

[0026] In the above-mentioned cleaning method for a thin film deposition tool, the cleaning gas stored in the cleaning gas storage tank may also be ethanol vapor.

[0027] In the above-mentioned cleaning method for a thin film deposition tool, the cleaning gas stored in the cleaning gas storage tank may also be acetone vapor.

[0028] The beneficial effects of the present invention are:

[0029] A cleaning method for thin film deposition jigs utilizes the principle that thin films crack under greater stress to resolve the damage introduced by conventional cleaning thin film deposition jigs, solves the cleaning problem of complex structure thin film deposition jigs, and solves the problem of thin film deposition product yield caused by incomplete cleaning of thin film deposition jigs. The method has obvious advantages in the deposition of high-quality, large-area film layers.

[0030] A method for cleaning a thin film deposition jig. Generally, the thickness of a thin film deposited on a bulk material substrate is limited. As the film thickness increases, the stress between the film and the substrate increases. When the thickness exceeds a certain level, the film will crack. Therefore, generally, the film coating thickness is much smaller than the critical thickness at which the film cracks. The present invention utilizes the relationship between the stresses of the film and the substrate, places the thin film deposition jig to be cleaned in a high vacuum device, and after reaching a certain vacuum level, introduces a gas that acts on the film stress into the high vacuum device. The gas changes the stress between the film and the substrate on the deposition jig. When the stress reaches the condition for film cracking, the film layer on the deposition jig begins to fall off, achieving the effect of cleaning the thin film deposition jig. This method not only does not damage the thin film deposition jig, but also has a good cleaning effect on thin film deposition jigs with complex structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of the cleaning device of the present invention;

[0032] In the figure: 1. Vacuum chamber; 2. Cleaning table; 3. Mechanical pump; 4. Molecular pump; 5. Vacuum valve; 6. Vacuum gauge; 7. Clean gas storage tank; 8. Dry gas storage tank; 9. Mass flow meter. DETAILED DESCRIPTION

[0033] Example 1

[0034] A cleaning device for a thin film deposition jig, such as Figure 1 As shown, it includes a vacuum chamber 1, a cleaning table 2, a mechanical pump 3, a molecular pump 4, a vacuum valve 5, a vacuum gauge 6, a clean gas storage tank 7, a dry gas storage tank 8, and a mass flow meter 9.

[0035] The main body of the device of the present invention is a vacuum chamber 1, a cleaning table 2 is arranged inside the chamber, a mechanical pump 3 and a molecular pump 4 are distributed at the bottom or side wall of the chamber, a mass flow meter 9 and a vacuum gauge 6 are arranged on the side wall of the vacuum chamber 1, the gas source is connected to the mass flow meter 9, and the vacuum valve 5 is used to connect the mechanical pump 3 with the vacuum chamber 1 and the molecular pump 4.

[0036] Before the cleaning process, dry gas needs to be introduced for the flushing process (during the flushing process, dry gas is introduced, and when the vacuum cavity reaches atmospheric pressure, vacuum is then evacuated, and this is repeated several times, generally 3 times), so that the vacuum cavity 1 can reach the preset vacuum degree.

[0037] A method for cleaning thin-film deposition jigs utilizes the stress relationship between the film and the substrate. The jig to be cleaned is placed in a high-vacuum device. After reaching a certain vacuum level, a gas that reacts to the film stress is introduced into the high-vacuum device. This gas changes the stress between the film and the substrate on the plating jig. When the stress reaches the condition that causes the film to crack, the film layer on the plating jig begins to fall off, achieving the effect of cleaning the thin-film deposition jig. This method not only does not damage the thin-film deposition jig, but also has a good cleaning effect on thin-film deposition jigs with complex structures. It includes the following steps:

[0038] Step 1: Place the thin film deposition fixture to be cleaned

[0039] Open the vacuum chamber, place the thin film deposition jig to be cleaned on the cleaning table, and close the vacuum chamber.

[0040] Step 2: Evacuate the vacuum chamber

[0041] Turn on the mechanical pump to evacuate the vacuum chamber. When the vacuum chamber reaches a certain vacuum degree, that is, when the vacuum degree changes little, turn off the mechanical pump.

[0042] Open the mass flow meter 9 (mass flow meter of the dry gas storage tank), introduce dry gas, and when the vacuum chamber reaches atmospheric pressure, turn on the mechanical pump;

[0043] Wait until the vacuum chamber reaches a certain vacuum degree (<10 -3 Torr), turn on the molecular pump, and when the vacuum degree of the vacuum chamber changes little, turn off the molecular pump and the mechanical pump;

[0044] Open the mass flow meter 9, introduce dry gas, and when the large vacuum chamber reaches atmospheric pressure, turn on the mechanical pump and wait until the vacuum chamber reaches a certain vacuum degree (<10 -3 Torr), turn on the molecular pump and maintain it for a while, the vacuum degree can reach 1×10 -6 to 1×10 -7 Torr.

[0045] Step 3: Cleaning the thin film deposition fixture

[0046] Turn on the mass flow meter 9 and introduce the cleaning gas, which can be water vapor, ethanol vapor, or acetone vapor. At this time, the vacuum degree in the chamber will decrease to a certain range as the gas is introduced, 1×10 -3 to 1×10 -5 Torr, depending on the thin film of different materials on the thin film deposition jig, the maintenance time is different. After the clean gas is fully in contact with the thin film on the thin film deposition jig, the film layer on the thin film deposition jig will crack due to the stress reaching the stress limit value, and then fall off completely.

Claims

1. A method for cleaning a thin film deposition jig, using a cleaning device for the thin film deposition jig; the cleaning device comprises a vacuum chamber (1), a cleaning table (2), a mechanical pump (3), a molecular pump (4), a vacuum valve (5), a clean gas storage tank (7), and a dry gas storage tank (8); A cleaning table (2) is provided in the vacuum chamber (1), and the cleaning table (2) is used to place a thin film deposition jig to be cleaned; The molecular pump (4), the clean gas storage tank (7), and the dry gas storage tank (8) are respectively connected to the vacuum chamber (1), and the mechanical pump (3) is respectively connected to the molecular pump (4) and the vacuum chamber (1) through the vacuum valve (5); It is characterized by: The steps include: Step 1: Place the thin film deposition fixture to be cleaned: Opening the vacuum chamber (1) of the cleaning device, placing the thin film deposition jig to be cleaned on the cleaning table (2), and closing the vacuum chamber (1); Step 2: Evacuate the vacuum chamber: The first step is to start the cleaning device and turn on the mechanical pump (3). The mechanical pump (3) starts to evacuate the vacuum chamber (1) until the vacuum degree of the vacuum chamber (1) is constant, and then turn off the mechanical pump; The second step is to open the dry gas storage tank (8) and let the dry gas flow into the vacuum chamber (1). When the pressure of the vacuum chamber 1 reaches 1 atmosphere, the dry gas storage tank (8) is closed and the mechanical pump (3) is turned on. In the third step, the mechanical pump (3) evacuates the vacuum chamber (1) until the vacuum degree of the vacuum chamber (1) is less than 10 -3 When the vacuum pressure reaches 0.01 Torr, the molecular pump (4) is turned on until the vacuum degree of the vacuum chamber (1) becomes constant, the molecular pump (4) is turned off, and the mechanical pump (3) is turned off; The fourth step is to open the dry gas storage tank (8) and introduce dry gas into the vacuum chamber (1). When the vacuum chamber (1) reaches 1 atmosphere, close the dry gas storage tank (8) and start the mechanical pump (3) until the vacuum degree of the vacuum chamber (1) is less than 10 -3 Torr, turn on the molecular pump until the vacuum degree of the vacuum chamber (1) is 1×10 -6 ~1×10 -7 Torr, turn off the molecular pump (4), turn off the mechanical pump (3); Step 3, cleaning of thin film deposition fixture: Open the clean gas storage tank (7) and let the clean gas flow into the vacuum chamber (1) until the pressure of the vacuum chamber (1) reaches 1×10 -3 ~1×10 -5 Torr, maintain a constant gas pressure until the film layer attached to the thin film deposition fixture falls off.

2. The cleaning method for a thin film deposition tool according to claim 1, wherein: The cleaning device further comprises a vacuum gauge (6), which is in communication with the vacuum chamber (1) and is used to measure the vacuum degree of the vacuum chamber (1).

3. The cleaning method for a thin film deposition tool according to claim 1 or 2, characterized in that: The cleaning device further comprises two mass flow meters (9), each of which is located on the connecting pipelines between the clean gas storage tank (7), the dry gas storage tank (8) and the vacuum chamber (1), and is used to measure the mass flow of the clean gas storage tank (7) and the dry gas storage tank (8).

4. The cleaning method for a thin film deposition tool according to claim 1, wherein: The gas stored in the dry gas storage tank (8) is dry nitrogen.

5. The cleaning method for a thin film deposition tool according to claim 1, wherein: The gas stored in the dry gas storage tank (8) is dry argon.

6. The method for cleaning a thin film deposition tool according to claim 1, wherein: The step 3 of thin film deposition tool cleaning further includes: The time during which the vacuum chamber (1) maintains a constant gas pressure is related to the physical properties and thickness of the thin film attached to the thin film deposition jig. When the clean gas is in full contact with the thin film attached to the thin film deposition jig and the stress generated between the thin film deposition jig and the attached thin film reaches a cracking stress, the attached thin film falls off.

7. The cleaning method for a thin film deposition tool according to claim 1, wherein: The clean gas stored in the clean gas storage tank (7) is water vapor.

8. The cleaning method for a thin film deposition tool according to claim 1, wherein: The clean gas stored in the clean gas storage tank (7) is ethanol vapor.

9. The cleaning method for a thin film deposition tool according to claim 1, wherein: The clean gas stored in the clean gas storage tank (7) is acetone vapor.

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