Pollution prevention mechanism for vacuum cavity gate valve

Abstract

The utility model discloses a mechanism for preventing a vacuum cavity gate valve from being polluted, and belongs to the technical field of vacuum cavity equipment. The mechanism comprises a shielding device arranged between a vacuum cavity and a gate valve, and the shielding device is used for protecting a plate surface of the gate valve and a gap between the gate valve and a valve base from being polluted by residual source materials. The shielding device is arranged between the cavity and the gate valve, so that the plate surface of the gate valve and a gap between the gate valve and the valve base are not polluted by residual source materials, the sealing performance, the stability and the service life of the gate valve can be effectively ensured, and the gate valve is not polluted while pollutants of the residual source materials are treated by opening the cavity.

Description

Technical Field

[0001] This utility model relates to the field of vacuum chamber equipment technology, and in particular to a mechanism for preventing contamination in a vacuum chamber gate valve. Background Technology

[0002] Gate valves are widely used in vacuum equipment for semiconductor material preparation, such as thermal evaporation equipment, magnetron sputtering equipment, and molecular beam epitaxy equipment. The precise control capability, good sealing performance, and stability of gate valves are crucial to ensuring the smooth progress of the process.

[0003] Gate valves play a crucial control role in vacuum chamber equipment. By opening and closing the gate valve, different vacuum chambers can be effectively connected and isolated, thereby effectively maintaining and adjusting the vacuum level of different chambers, ensuring the normal operation of the equipment and meeting different process requirements. However, residual source material evaporated or sputtered during sample growth can deposit on the gate valve's surface, in the gap between the gate valve and the valve base, etc., causing contamination and gas leakage, directly affecting the stability of the entire vacuum system and the process effect.

[0004] Currently, the usual method for dealing with gate valves contaminated by residual source materials is to periodically shut down the machine to open the chamber for inspection and cleaning of the gate valve plate surface, the gap between the gate valve and the valve base, etc. However, this can lead to production interruptions and may even cause a decline in the quality of the grown sample material, resulting in economic losses. This method also increases the number of downtimes and maintenance workload in addition to equipment failures. If the cleaning method is not appropriate, it may even increase the cost of maintenance and replacement. Utility Model Content

[0005] The purpose of this utility model is to provide a mechanism for preventing contamination of a vacuum chamber gate valve. This mechanism includes a shielding device disposed between the chamber and the gate valve. The shielding device protects the gate valve's surface and the gap between the gate valve and the valve base from contamination by residual source materials. The shielding device includes:

[0006] A shielding valve is installed in a pipe connected to the gate valve outside the cavity. The shielding valve includes a vertically movable baffle inserted into the pipe and a residual source material collection groove located at the bottom inside the pipe. During sample growth, the baffle moves downward to protect the gate valve; or

[0007] A pre-gate valve is installed in a pipeline connected to the gate valve outside the cavity. The pre-gate valve is located between the cavity and the gate valve. During sample growth, the pre-gate valve is closed to protect the gate valve.

[0008] Preferably, the baffle plate includes a baffle plate body, which is blade-shaped in general. Its lower half is sealed to the pipe through a flange. The top of the baffle plate body is provided with a thread that mates with a screw. The lower end of the screw is connected to a bellows inner rod, and the lower end of the bellows inner rod is connected to a baffle. The baffle can close the pipe by moving downward.

[0009] Preferably, the screw moves up and down, causing the upper flange of the bellows connected to the upper end of the bellows to move axially, thereby driving the bellows to move telescopically; the upper end of the bellows is connected to the upper flange of the bellows, and its lower end is connected to the baffle body through the lower flange; the inner rod of the bellows is connected to the baffle through connecting screws; the up and down movement of the screw causes the bellows to move telescopically, thereby causing the baffle to move up and down and meeting the airtightness requirements.

[0010] Preferably, the bellows and the screw are connected by flanges. High-quality corrosion-resistant and high-pressure resistant flanges and sealing gaskets with appropriate elasticity, hardness and size are selected. Before installation, ensure that all connection surfaces are clean and dry. During installation, tighten the bolts of the connecting flanges appropriately to avoid over-tightening or loosening, which may cause the bellows to deform or leak, so as to ensure the sealing and stability of the bellows in the vacuum environment.

[0011] Preferably, the flange connecting the shield body and the pipeline is a CF metal sealing flange. A metal sealing ring is provided between the two flange surfaces. The metal sealing ring is made of a metal sealing material that is easily deformable and suitable for ultra-high vacuum flanges, such as silver-plated alloy. When subjected to pressure, the sealing ring and the flange surface form a dense metal-metal contact, thereby achieving an effective seal.

[0012] Preferably, no sealing ring is provided between the pre-gate valve and the valve base, so that residual source material is trapped therein, so that during open-cavity maintenance, only the residual source material in the pre-gate valve and the gap between the pre-gate valve and the valve base is cleaned.

[0013] Preferably, the pre-gate valve and the cavity pipeline are connected using a CF metal-sealed flange. A metal sealing ring is provided between the two flange surfaces. The metal sealing ring is made of a malleable material suitable for ultra-high vacuum flange sealing, such as a silver-plated alloy. Under pressure, the sealing ring forms a dense metal-metal contact with the flange surface, thereby achieving an effective seal. Furthermore, during installation, the valve and cavity pipeline are aligned correctly to avoid any gaps and ensure a tight seal. When tightening the valve bolts, the torque value specified for the valve is followed to ensure a good valve seal and prevent leakage due to loose bolts.

[0014] Preferably, the baffle is made of stainless steel, aluminum alloy or titanium alloy.

[0015] The beneficial effects of this utility model include:

[0016] This invention, by setting a shielding device between the cavity and the gate valve, ensures that the gate valve plate surface and the gap between the gate valve and the valve base are not contaminated by residual source materials. This effectively ensures the sealing performance, stability and service life of the gate valve, and the gate valve will not be contaminated while the cavity is opened to remove residual source material contaminants. Attached Figure Description

[0017] Figure 1 The shield that moves up and down is shown in Example 1.

[0018] Figure 2 This is a schematic diagram of a collection tank for residual source material installed under a shield in Example 1.

[0019] Figure 3 This is a cross-sectional view of the baffle plate that moves up and down in Embodiment 1.

[0020] Figure 4 This is a schematic diagram of the double gate valve in Example 2.

[0021] Figure 5 Example 2 is a front gate valve without a sealing ring.

[0022] In the diagram: 100-cavity, 200-channel, 300-gate valve; 2-blocking valve, 21-collection tank, 23-manual drive unit, 231-support frame, 232-screw, 234-bellows, 2341-upper flange of bellows, 2342-lower flange of bellows, 2343-inner rod of bellows, 2344-connecting screw, 24-baffle, 26-flange; 3-front gate valve, 31-gap. Detailed Implementation

[0023] The technical solution of this utility model will be further described below with reference to the embodiments.

[0024] Example 1

[0025] like Figure 1 and Figure 2 As shown, a baffle valve is installed in the pipe 200 connected to the gate valve 300 outside the cavity 100. The baffle valve 2 is made of stainless steel or other materials, and a collection tank 21 for residual source material is set at the bottom of the baffle valve 2. When the cavity is opened for maintenance, the residual source material in the collection tank 21 is processed.

[0026] like Figure 3As shown, the shielding valve 2 includes a shielding plate body, which is blade-shaped in general. Its lower half is sealed to the pipeline 200 through a flange 26. A manual drive unit 23 is provided at the top of the shielding plate body. A screw 232 that can move up and down is provided below the manual drive unit 23. The screw 232 is driven to move up and down by the manual drive unit. The lower end of the screw 232 is connected to a bellows inner rod 2343. The lower end of the bellows inner rod 2343 is connected to a baffle 24. The baffle 24 can close the pipeline 200 by moving downward.

[0027] The upper flange 2341 of the bellows, which is connected to the upper end of the bellows 234, moves axially by rotating the screw 232 up and down, thereby driving the bellows 234 to move telescopically. The upper end of the bellows 234 is connected to the upper flange 2341, and its lower end is connected to the baffle body through the lower flange 2342. The inner rod 2343 of the bellows is connected to the baffle 24 through the connecting screw 2344. The up and down movement of the screw 232 drives the telescopic movement of the bellows 234, thereby driving the baffle 24 to move up and down and meeting the airtightness requirements.

[0028] The bellows 234 and the screw 232 are connected by a flange. High-quality corrosion-resistant and high-pressure resistant flanges and sealing gaskets with appropriate elasticity, hardness and size are selected. Before installation, ensure that all connection surfaces are clean and dry. During installation, tighten the bolts of the connecting flange appropriately to avoid over-tightening or over-loosening, which may cause the bellows to deform or leak, so as to ensure the sealing and stability of the bellows in the vacuum environment.

[0029] The bellows 234 and the cavity pipe 200 are connected by a CF metal sealing flange 26. A metal sealing ring is provided between the two flange surfaces. The metal sealing ring is made of a metal sealing material that is easily deformable and suitable for ultra-high vacuum flanges, such as silver-plated alloy. When subjected to pressure, the sealing ring and the flange surface form a dense metal-metal contact, thereby achieving an effective seal.

[0030] Example 2

[0031] A double gate valve is used, such as Figure 4 and Figure 5 As shown, no sealing ring 31 is provided between the pre-gate valve 3 connected to the cavity 100 and the valve base. During sample growth, both the pre-gate valve 3 and the gate valve 300 (connected to the pre-gate valve) are in the closed state. The pre-gate valve 3 protects the gate valve 300 from contamination by residual source material. The absence of a sealing ring between the pre-gate valve 3 and the valve base also allows residual source material to become trapped within it. During cavity maintenance, only the pre-gate valve 3 and the residual source material in the gap 31 between the pre-gate valve 3 and the valve base need to be cleaned. The use of a double gate valve effectively ensures the sealing performance, stability, and service life of the gate valves.

[0032] The pre-gate valve 3 is connected to the cavity pipeline 200 via a CF metal sealing flange. A metal sealing ring is provided between the two flange surfaces. The metal sealing ring is made of a malleable material suitable for ultra-high vacuum flange sealing, such as a silver-plated alloy. Under pressure, the sealing ring forms a dense metal-metal contact with the flange surface, thereby achieving an effective seal. Furthermore, during installation, the valve and cavity pipeline must be correctly aligned to avoid any gaps and ensure a tight seal. When tightening the valve bolts, the torque value specified for the valve must be followed to ensure a good valve seal and prevent leakage due to loose bolts.

Claims

1. A mechanism for preventing contamination in a vacuum chamber gate valve, characterized in that, The mechanism includes a shielding device between the vacuum chamber and the gate valve, the shielding device being used to protect the gate valve's plate surface and the gap between the gate valve and the valve base from contamination by residual source material; the shielding device includes: A shielding valve is installed in a pipe connected to the gate valve outside the cavity. The shielding valve includes a vertically movable baffle inserted into the pipe and a residual source material collection groove located at the bottom inside the pipe. During sample growth, the baffle moves downward to protect the gate valve; or A pre-gate valve is installed in a pipeline connected to the gate valve outside the cavity. The pre-gate valve is located between the cavity and the gate valve. During sample growth, the pre-gate valve is closed to protect the gate valve.

2. The mechanism for preventing contamination of the vacuum chamber gate valve according to claim 1, characterized in that: The shielding valve includes a shielding plate body, which is blade-shaped. Its lower half is sealed to the pipeline through a flange. The top of the shielding plate body is equipped with a manual drive unit connected to a screw. The screw is driven to move up and down by the manual drive unit. The lower end of the screw is connected to a bellows inner rod, and the lower end of the bellows inner rod is connected to a baffle. The baffle moves downward to close the pipeline.

3. The mechanism for preventing contamination of the vacuum chamber gate valve according to claim 2, characterized in that: The screw moves up and down, causing the upper flange connected to the bellows to move axially, thereby driving the bellows to extend and retract. The upper end of the bellows is connected to the upper flange, and its lower end is connected to the baffle body through the lower flange. The inner rod of the bellows is connected to the baffle through connecting screws. The up and down movement of the screw causes the bellows to extend and retract, thereby causing the baffle to move up and down and meeting the airtightness requirements.

4. The mechanism for preventing contamination of the vacuum chamber gate valve according to claim 3, characterized in that: The upper and lower flanges of the bellows are made of corrosion-resistant and high-pressure resistant materials, and a sealing gasket with appropriate elasticity, hardness and size is provided between the flange and the pipe.

5. The mechanism for preventing contamination of the vacuum chamber gate valve according to claim 2, characterized in that: The flange connecting the shield plate body and the pipeline is a CF metal sealing flange, and a metal sealing ring is provided between the two flange surfaces. The metal sealing ring is made of a metal sealing material that is easily deformable and suitable for ultra-high vacuum flanges.

6. The mechanism for preventing contamination in a vacuum chamber gate valve according to claim 1, characterized in that: No sealing ring is provided between the pre-gate valve and the valve base, so that residual source material is trapped therein. This is used to clean only the residual source material in the pre-gate valve and the gap between the pre-gate valve and the valve base during open-cavity maintenance.

7. The mechanism for preventing contamination of the vacuum chamber gate valve according to claim 1 or 6, characterized in that: The pre-gate valve is connected to the cavity pipeline using a CF metal sealing flange. A metal sealing ring is provided between the two flange surfaces. The metal sealing ring is made of a material that is easily deformable and suitable for metal sealing of ultra-high vacuum flanges.

8. The mechanism for preventing contamination of the vacuum chamber gate valve according to any one of claims 2-6, characterized in that: The baffle is made of stainless steel, aluminum alloy or titanium alloy.

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