Plasma atomic layer deposition equipment capable of avoiding coating film on inner wall of quartz tube

Abstract

The utility model provides plasma atomic layer deposition equipment capable of avoiding precursor source deposition on the inner wall of a quartz tube, which comprises a plasma generator, a vacuum cavity, a gate valve and a vacuum pump, a large-size gate valve is additionally arranged between a vacuum cavity and a plasma generator, so that a precursor source in the vacuum cavity is prevented from entering a quartz tube in the plasma generator; the problems that the plasma atomic layer deposition process is unstable, the film performance becomes poor and the equipment maintenance cost is high due to the fact that a precursor source forms sediments in a quartz tube are solved. Meanwhile, in consideration of the problem that a large-size gate valve is possibly damaged when the pressure difference between the two sides is large, the plasma generator is connected with the vacuum pump, the diaphragm valve is additionally arranged between the plasma generator and the vacuum pump, the diaphragm valve is opened after the gate valve is closed, the two sides of the gate valve are both connected with the vacuum pump, and the problem that the gate valve is damaged due to the large pressure difference between the two sides of the gate valve is solved.

Description

Technical Field

[0001] The utility model relates to a plasma atomic layer deposition device for avoiding film coating on the inner wall of a quartz tube, belonging to the technical field of atomic layer deposition. Background Art

[0002] Atomic layer deposition (ALD) is a specialized chemical vapor deposition (CVD) technique for ultra-thin films. It forms thin films by alternately introducing pulses of vapor precursors into a reaction chamber and chemically adsorbing them onto a substrate surface. It features self-limiting growth, precise control of film thickness at the atomic level, high uniformity, excellent three-dimensional conformality, and the ability to deposit at low temperatures. Plasma-enhanced ALD optimizes ALD by injecting plasma to generate a large number of highly active particles. This broadens the range of precursor sources available for ALD, shortens the reaction cycle time, and reduces the temperature requirement for film formation, enabling ALD to be performed at even lower temperatures.

[0003] Plasma atomic layer deposition equipment is usually connected to a plasma generator on the basis of a deposition equipment. The plasma generator includes a discharge chamber (usually a section of quartz tube). The gas is heated and ionized in the discharge chamber to generate plasma gas, and then the plasma gas is introduced into the vacuum chamber of the deposition equipment as a reaction source to participate in thin film deposition. In existing plasma atomic layer deposition equipment, the plasma generator is usually directly connected to the vacuum chamber. Therefore, when a precursor source is introduced into the vacuum chamber during the deposition process, the precursor source will enter the quartz tube in the plasma generator and react with the generated plasma gas, thereby generating a thin film on the inner wall of the quartz tube. When the deposited film has a certain conductivity, this will interfere with the distribution of the internal electric field, thereby causing instability during the discharge process, affecting the uniformity, stability and repeatability of the plasma gas generation; in addition, the conductivity of the inner wall of the quartz tube may also change the charge distribution and energy transfer in the plasma, thereby changing the conditions of the chemical reaction and affecting the coating rate of the sample thin film. When the film on the inner wall of the quartz tube is too thick, some of it may flake off and mix into the plasma atomic layer deposition process, causing impurities to appear when the substrate is coated, which can reduce the quality and purity of the film. Therefore, the quartz tube needs to be cleaned or replaced regularly, which to a certain extent increases the maintenance cost of the equipment and shortens its service life.

[0004] In summary, due to the direct connection between the vacuum chamber and the plasma generator in traditional plasma atomic layer deposition equipment, a deposited film will also form on the inner wall of the quartz tube inside the plasma generator during the film deposition process, causing problems such as unstable plasma atomic layer deposition process, poor film performance, and high equipment maintenance costs. Utility Model Content

[0005] In order to solve the above technical problems, the present invention provides a plasma atomic layer deposition device that avoids coating on the inner wall of a quartz tube. By adding a large-sized gate valve 5 between the vacuum chamber 6 and the plasma generator 4, the precursor source in the vacuum chamber is prevented from entering the quartz tube inside the plasma generator, thereby solving the problem that the precursor source forms deposits inside the quartz tube, thereby causing unstable plasma atomic layer deposition process, poor film performance, and high equipment maintenance cost; at the same time, considering the problem that the large-sized gate valve 5 may be damaged when the pressure difference on both sides is large, this solution connects the plasma generator 4 with the vacuum pump 10 and adds a diaphragm valve 2 in the middle. After the gate valve 5 is closed, the diaphragm valve 2 is opened, so that the top and bottom of the gate valve 5 are both connected to the vacuum pump 10, solving the problem that the gate valve 5 is damaged by the large pressure difference on both sides.

[0006] A plasma atomic layer deposition device for preventing coating on the inner wall of a quartz tube comprises a plasma generator 4, a vacuum chamber 6, a gate valve 5, and a vacuum pump 10. The gate valve 5 is arranged between the plasma generator 4 and the vacuum chamber 6 to isolate the gas. The vacuum chamber 6 is connected to the vacuum pump 10 via a first pipeline 9. The upper portion of the plasma generator 4 is connected to the vacuum pump via a second pipeline 3. A diaphragm valve 2 is installed on the second pipeline 3 to control the pressure difference across the gate valve 5 to prevent damage to the gate valve 5 due to a large pressure difference across the two sides.

[0007] In one embodiment, the plasma generator 4 includes a box body 4-3 and a quartz tube 4-1 and a copper coil 4-2 inside, and the copper coil 4-2 is wound on the outer wall of the quartz tube 4-1; the plasma generator 4 is provided with a plasma inlet 1, which is connected to the plasma gas source. At the same time, the plasma inlet 1 is also connected to the vacuum pump 10 through a second pipeline 3, and a diaphragm valve 2 is provided on the second pipeline 3.

[0008] In one embodiment, a precursor source air inlet 7 and a cavity air outlet 8 are provided on the vacuum cavity 6 . The precursor source air inlet 7 is connected to the precursor source, and the cavity air outlet 8 is connected to the vacuum pump 10 through a first pipeline 9 .

[0009] In one embodiment, the first pipeline 9 and the second pipeline 3 are stainless steel pipelines.

[0010] In one embodiment, the gate valve 5 is a large-sized gate valve.

[0011] In one embodiment, when the gate valve 5 is closed, the diaphragm valve 2 is open.

[0012] Advantages of this utility model:

[0013] 1. This new method adds a plug-in valve between the vacuum chamber and the plasma generator, which prevents the precursor source in the vacuum chamber from entering the quartz tube inside the plasma generator. This solves the problem of the precursor source forming deposits inside the quartz tube, causing unstable plasma atomic layer deposition process, poor film performance, and high equipment maintenance costs.

[0014] 2. The utility model chooses to install a large-sized plug valve, which can tightly connect the vacuum chamber and the plasma generator without affecting the utilization rate of the plasma during the plasma atomic layer deposition process.

[0015] 3. The utility model adds a diaphragm valve and a stainless steel pipeline above the plasma generator for connecting the vacuum pump, so that both sides of the gate valve are connected to the vacuum pump, solving the problem of large pressure difference on both sides of the gate valve and possible damage to the gate valve.

[0016] 4. The utility model controls the gate valve to open before the plasma pulse and close the gate valve after the plasma pulse ends, effectively preventing the precursor source from entering the quartz tube inside the plasma generator when the gate valve is opened and closed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic structural diagram of the plasma atomic layer deposition equipment for avoiding coating of the inner wall of the quartz tube provided by the utility model, wherein 1 is the plasma air inlet, 2 is the diaphragm valve, 3 is the stainless steel pipeline, 4 is the plasma generator, 4-1 is the quartz tube, 4-2 is the copper coil, 4-3 is the box, 5 is the plug-in valve, 6 is the vacuum chamber, 7 is the precursor source air inlet, 8 is the cavity air outlet, 9 is the stainless steel pipeline, and 10 is the vacuum pump.

[0018] Figure 2 Comparison pictures of the inner wall of a quartz tube after conducting an indium oxide experiment using a traditional plasma atomic layer deposition device and a plasma atomic layer deposition device provided by the present invention that avoids coating the inner wall of the quartz tube.

[0019] Figure 3 Comparison pictures of the inner wall of a quartz tube after a gallium oxide experiment using a conventional plasma atomic layer deposition device and a plasma atomic layer deposition device provided by the present invention that avoids coating of the inner wall of the quartz tube. DETAILED DESCRIPTION

[0020] The following is a detailed description of the present invention.

[0021] Example 1

[0022] The present invention provides a plasma atomic layer deposition device that avoids coating on the inner wall of a quartz tube. The structure of the device is as follows: Figure 1As shown, the device comprises a plasma generator 4, a vacuum chamber 6, a gate valve 5, and a vacuum pump 10. The gate valve 5 is disposed between the plasma generator 4 and the vacuum chamber 6. The vacuum chamber 6 is connected to the vacuum pump 10 via a first pipeline 9. The upper portion of the plasma generator 4 is connected to the vacuum pump 10 via a second pipeline 3. A diaphragm valve 2 is installed on the second pipeline 3 to control the pressure difference across the gate valve 5.

[0023] The device sets a gate valve 5 between the vacuum chamber 6 and the plasma generator 4 to separate the vacuum chamber 6 and the plasma generator 4, thereby preventing the precursor source in the vacuum chamber 6 from entering the quartz tube inside the plasma generator 4, thereby preventing the precursor source from coating the inner wall of the quartz tube.

[0024] In the plasma atomic layer deposition apparatus provided in this embodiment for preventing coating on the inner wall of a quartz tube, a plasma generator 4 includes a housing 4-3, an internal quartz tube 4-1, and a copper coil 4-2 wound around the outer wall of the quartz tube 4-1. A plasma inlet 1 is provided on the plasma generator 4. A plasma gas source is connected to the plasma inlet 1 via a gas source pipeline. To prevent damage to the gate valve 5 due to a large pressure differential across the gate valve 5, the plasma inlet 1 is also connected to a vacuum pump 10 via a second pipeline 3. A diaphragm valve 2 is also provided on the second pipeline 3. The opening and closing of the diaphragm valve 2 ensures that the pressure differential across the gate valve 5 remains consistent when the vacuum chamber 6 is evacuated.

[0025] In one embodiment, a precursor source air inlet 7 and a cavity air outlet 8 are provided on the vacuum cavity 6 . The precursor source air inlet 7 is connected to the precursor source, and the cavity air outlet 8 is connected to the vacuum pump 10 through a first pipeline 9 .

[0026] In one embodiment, the gate valve 5 is a large-sized gate valve.

[0027] In one embodiment, the gate valve 5 can be a CF series gate valve, such as CF100, CF63, CF80, CF150, CF200, CF250, CF300, CF400 gate valves, etc.

[0028] The interface between the vacuum chamber of the plasma-enhanced atomic layer deposition equipment and the quartz tube in the plasma generator is large in size, and conventional diaphragm valves and single-phase valves cannot be directly connected. Therefore, the present application adopts a large-sized gate valve instead of reducing the diameter of the interface or connecting a valve from the side, so as not to affect the ventilation efficiency and utilization rate of the plasma and avoid the adverse effects that may be brought to the thin film deposition effect. Although the use of a large-sized gate valve can avoid the impact on ventilation efficiency and utilization rate, the commonly used large-sized gate valve has a long response time for opening and closing. During the opening and closing time, it is still impossible to guarantee that the precursor will not enter the interior of the quartz tube. Moreover, during the use of the large-sized gate valve, if the pressure difference between the two sides exceeds several thousand Pa, the gate valve may be damaged. During use, after the gate valve is closed, the lower end of the gate valve is directly connected to the vacuum pump and will be evacuated to a vacuum state, while the upper end of the gate valve is not connected to the vacuum pump, so the pressure will continue to rise, and the pressure difference between the two sides exceeds the tolerance range of the gate valve, causing damage to the gate valve. Taking all these issues into consideration, the present application solution connects the plasma generator 4 above the gate valve 5 to the vacuum pump 10 through the second pipeline 3, and further provides a diaphragm valve 2 on the second pipeline 3, thereby solving the problem of long response time for opening and closing of the gate valve and the problem of large pressure difference on both sides of the gate valve.

[0029] After the previous precursor source is cleaned and the gate valve 5 is controlled to be fully opened, the plasma pulse is performed; after the plasma pulse is completed, the gate valve 5 is controlled to be closed and the diaphragm valve 2 is opened at the same time to ensure that the pressures at both ends of the gate valve 5 are stable at the same level to prevent damage caused by a large pressure difference on both sides of the gate valve 5.

[0030] The working principle of this utility model:

[0031] Vacuuming stage: Place the sample to be deposited into the vacuum chamber 6, close the gate valve 5, and use the vacuum pump 10 to evacuate the vacuum chamber 6. During this process, to prevent the gate valve 5 from being damaged due to a large pressure difference on both sides, the diaphragm valve 2 is opened to ensure that the pressure on both sides of the gate valve 5 is always consistent.

[0032] Thin film deposition stage: after the vacuum chamber 6 is evacuated, the gate valve 5 remains closed and the diaphragm valve 2 remains open; the precursor source is introduced into the vacuum chamber 6 through the precursor source air inlet 7, and the surface of the sample to be deposited in the vacuum chamber 6 undergoes the first half reaction of thin film deposition; since the gate valve 5 is always in a closed state, the precursor source does not enter the plasma generator 4; after the first half reaction of thin film deposition is completed, the precursor source air inlet 7 is closed, and the vacuum pump 10 extracts the remaining precursor source in the vacuum chamber 6 through the cavity air outlet 8. After cleaning is completed, the gate valve 5 is opened again and the diaphragm valve 2 is closed, so that the plasma pulse generated by the plasma generator 4 is passed into the vacuum chamber 6 to complete the second half reaction of thin film deposition. In this way, the entire thin film deposition process is completed. At this time, the gate valve 5 is closed, the diaphragm valve 2 is opened, and the vacuum pump 10 is used to complete the cleaning of the remaining plasma in the vacuum chamber 6.

[0033] According to the above description, it can be seen that during the entire thin film deposition process, the precursor source does not enter the quartz tube inside the plasma generator 4, so no thin film will be produced on the inner wall of the quartz tube 4-1; and in the equipment in which the vacuum chamber 6 and the plasma generator 4 are directly connected, the precursor source will enter the quartz tube. Although there is a remaining precursor source cleaning process, during the actual deposition process, due to the complexity of the internal pipelines of the equipment and the limitation of the cleaning time, there will be a situation where the cleaning is not thorough, so a thin film will be produced on the inner wall of the quartz tube, but this will not happen in the present application solution.

[0034] To verify the deposition effect of the plasma atomic layer deposition device provided by the present invention for avoiding coating on the inner wall of the quartz tube, the following experiments on indium oxide and gallium oxide were conducted on samples using the present invention device and a traditional plasma atomic layer deposition device, respectively, and the inner wall of the quartz tube was observed:

[0035] 1. Indium oxide experiment tests the inner wall of the quartz tube:

[0036] Using diethyl zinc and plasma oxygen as precursor sources, the sample was coated using the device of the present invention and a traditional plasma atomic layer deposition device, respectively. The traditional plasma atomic layer deposition device is a device on the market in which a vacuum chamber 6 and a plasma generator 4 are directly connected.

[0037] The results are as follows Figure 2 As shown, Figure 2 (a) shows the inner wall of a quartz tube after an indium oxide experiment using a conventional plasma atomic layer deposition device. It can be seen that the inner wall of the quartz tube is clearly coated with a precursor source, and the test found that the inner wall of the quartz tube is conductive. Figure 2 Middle (b) is a picture of the inner wall of the quartz tube after the indium oxide experiment was carried out using the equipment of the present invention. It can be seen that there is no obvious precursor source coating on the inner wall of the quartz tube, and the test found that it is not conductive.

[0038] 2. Using triethylgallium and plasma oxygen as precursor sources, the samples were coated using the equipment of the present invention and the traditional plasma atomic layer deposition equipment respectively.

[0039] The results are as follows Figure 3 As shown, Figure 3 (a) shows the inner wall of a quartz tube after a gallium oxide experiment using conventional plasma atomic layer deposition equipment. It can be seen that the inner wall of the quartz tube is clearly coated with a precursor source, and the test found that the inner wall of the quartz tube is conductive. Figure 3 Middle (b) is a picture of the inner wall of the quartz tube after the gallium oxide experiment was carried out using the equipment of the present invention. It can be seen that there is no obvious precursor source coating on the inner wall of the quartz tube, and the test found that it is not conductive.

[0040] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this technology may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A plasma atomic layer deposition device for avoiding coating on the inner wall of a quartz tube, characterized in that: The device comprises a plasma generator (4), a vacuum chamber (6), a gate valve (5) and a vacuum pump (10); wherein the gate valve (5) is arranged between the plasma generator (4) and the vacuum chamber (6); the vacuum chamber (6) and the vacuum pump (10) are connected via a first pipeline (9); the upper portion of the plasma generator (4) is connected to the vacuum pump (10) via a second pipeline (3); and a diaphragm valve (2) is installed on the second pipeline (3) to control the pressure difference at both ends of the gate valve (5).

2. The plasma atomic layer deposition device for avoiding coating on the inner wall of a quartz tube according to claim 1, characterized in that: The plasma generator (4) is provided with a plasma gas inlet (1) connected to a plasma gas source. Simultaneously, the plasma gas inlet (1) is also connected to a vacuum pump (10) via a second pipeline (3).

3. The plasma atomic layer deposition device for avoiding coating on the inner wall of a quartz tube according to claim 2, characterized in that: The vacuum cavity (6) is provided with a precursor source air inlet (7) and a cavity air outlet (8); the precursor source air inlet (7) is connected to the precursor source, and the cavity air outlet (8) is connected to a vacuum pump (10) via a first pipeline (9).

4. The plasma atomic layer deposition device for avoiding coating on the inner wall of a quartz tube according to claim 3, characterized in that: The first pipeline (9) and the second pipeline (3) are stainless steel pipelines.

5. The plasma atomic layer deposition device for avoiding coating on the inner wall of a quartz tube according to claim 4, characterized in that: The plasma generator (4) comprises a box (4-3), a quartz tube (4-1) and a coil (4-2) located inside the box; the coil (4-2) is wound on the outer wall of the quartz tube (4-1).

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