Plasma processing apparatus and equipment therefor
By designing a special structure for the inlet pipe and outlet unit in the plasma processing device, the problem of uneven distribution of reactive gases was solved, achieving uniform distribution and efficient ionization of plasma, thus improving the thin film deposition effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI QINGJIANTING TECH CO LTD
- Filing Date
- 2025-08-02
- Publication Date
- 2026-07-21
AI Technical Summary
In existing plasma processing devices, the reaction gas is unevenly distributed under the influence of gravity, which leads to uneven distribution of plasma in the chamber and affects the thin film deposition effect.
Design a plasma processing device with an inlet pipe located on the side of the electrode rod away from the furnace tube process cavity, and an outlet unit evenly distributed along the length of the electrode rod. The outlet holes are designed with gradually increasing diameters to ensure that the reaction gas is uniformly ionized before entering the furnace tube process cavity.
This achieves uniform plasma distribution, improves ionization efficiency, avoids waste of reactive gases, provides a uniform gas flow environment, and provides stable conditions for thin film deposition processes.
Smart Images
Figure CN224531031U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of plasma processing, and in particular to a plasma processing apparatus and equipment. Background Technology
[0002] Atomic layer deposition (ALD) is a key process technology for semiconductors, especially plasma-enhanced atomic layer deposition (PEAD). In this process, the reactant gas needs to be ionized. The ionized gas forms plasma, which then reacts with the source gas to form the desired thin film.
[0003] Currently, the chamber required for plasma formation generally consists of an inlet pipe, electrode rods, and electrode plates. The reactive gas enters the chamber through the inlet pipe, and the electrode rods and electrode plates form an electric field in the chamber. The reactive gas is ionized into plasma under the action of the electric field. However, because the reactive gas enters the chamber through the inlet pipe, the reactive gas is unevenly distributed under the action of gravity, which leads to uneven distribution of the ionized plasma in the chamber, affecting the deposition effect on the wafer surfaces above and below the furnace tube. Utility Model Content
[0004] To improve the problem of uneven plasma distribution, this application provides a plasma processing apparatus and equipment.
[0005] The plasma processing device and equipment provided in this application adopt the following technical solution: A plasma processing device and apparatus includes a furnace tube body, within which a furnace tube process chamber and a plasma reaction chamber are disposed. An inlet pipe and an electrode rod are installed within the plasma reaction chamber. The inlet pipe is located on the side of the electrode rod away from the furnace tube process chamber. Two electrode plates are disposed within the furnace tube body, respectively located on opposite sides of the electrode rod. The bottom end of the inlet pipe is an inlet for introducing reaction gas, and the top end of the inlet pipe is a gas pipe end. An outlet unit is disposed on the inlet pipe, and the reaction gas within the inlet pipe is ejected through several outlet units and uniformly distributed along the length of the electrode rod.
[0006] By adopting the above technical solution, the electrode rod and the gas inlet pipe are surrounded on three sides by the plasma reaction chamber. After the reactive gas is introduced from the gas inlet end of the gas inlet pipe, the reactive gas will enter the plasma reaction chamber through the gas outlet unit. Then, under the action of the electric field formed by the electrode rod and the electrode plate, it will be ionized. After the reactive gas is ionized into plasma, it will enter the furnace tube process chamber. Since the amount of gas ejected by the gas outlet unit is evenly distributed, the plasma distribution is uniform, which provides a uniform airflow environment for the subsequent thin film deposition process. Moreover, the gas inlet pipe is located on the side of the electrode rod away from the furnace tube process chamber, so that the reactive gas must be ionized before entering the furnace tube process chamber, avoiding the waste of reactive gas and ensuring ionization efficiency.
[0007] Preferably, the air outlet unit includes a plurality of air outlet holes, which are equally spaced along the length of the air inlet pipe, and the diameter of the plurality of air outlet holes increases sequentially from the air inlet end to the end of the air pipe.
[0008] By adopting the above technical solution, the flow rate of the reaction gas introduced from the inlet is constant. Under the action of gravity, the amount of gas ejected from the outlet near the inlet will be larger, while the amount of gas ejected from the outlet far from the inlet will be smaller. Since the diameter of the outlet increases sequentially from the inlet to the end of the gas pipe, the amount of gas ejected from each outlet is more uniform, thereby improving the uneven plasma distribution caused by gravity and providing a uniform airflow environment for the subsequent thin film deposition process.
[0009] Preferably, the air outlet is centrally located on the side of the air inlet pipe closest to the electrode rod.
[0010] By adopting the above technical solution, the outlet is set at the center of the inlet pipe near the electrode rod, which helps the reaction gas to flow more smoothly to the vicinity of the electrode rod, so that the reaction gas can be fully ionized when passing through the plasma reaction chamber.
[0011] Preferably, the air outlet unit is provided in two sets, and the two sets of air outlet units are arranged at intervals along the circumference of the air inlet pipe. The included angle between the two sets of air outlet units is no greater than 60°, and the distance between the two sets of air outlet units and the electrode rod is equal.
[0012] By adopting the above technical solution, the setting of two sets of gas outlet units makes the efficiency of the reaction gas entering the plasma reaction chamber higher. After the reaction gas enters the plasma reaction chamber through the two sets of gas outlet units, it can diffuse around the electrode rod. The electrode rod prevents the reaction gas from directly entering the furnace tube process chamber, so that the reaction gas must pass through the ionization zone formed by the electrode rod and the electrode plate before it can enter the furnace tube process chamber, thereby improving the ionization efficiency.
[0013] Preferably, the air outlet unit includes several sets of air hole units, which are equally spaced along the length of the air inlet pipe. Each air hole unit includes several air outlet holes equally spaced along the length of the air inlet pipe, and the diameter of the air outlet holes of the several air hole units increases sequentially from the air inlet end to the end of the air pipe.
[0014] By adopting the above technical solution, several groups of gas outlet holes with different diameters help to maintain the consistency of airflow and avoid uneven distribution of reaction gas flow. At the same time, grouping several gas outlet holes can improve processing convenience and reduce processing costs.
[0015] Preferably, the air outlet hole is centrally located on the side of the air inlet pipe closest to the electrode rod.
[0016] By adopting the above technical solution, the outlet is set at the center of the inlet pipe near the electrode rod, which helps the reaction gas to flow more smoothly to the vicinity of the electrode rod, so that the reaction gas can be fully ionized when passing through the plasma reaction chamber.
[0017] Preferably, the air outlet unit is provided in two sets, and the two sets of air outlet units are located on the side of the air inlet pipe close to the electrode rod. The included angle between the two sets of air outlet units is no greater than 60°, and the distance between the two sets of air outlet units and the electrode rod is equal.
[0018] By adopting the above technical solution, the two sets of gas outlet units are set on the side of the gas inlet pipe close to the electrode rod, which helps to better distribute the airflow evenly. Furthermore, by controlling the airflow direction by the included angle, the time it takes for the airflow to bypass the electrode rod can be changed, thereby improving the sufficiency of the ionization of the reaction gas.
[0019] Preferably, the bottom of the plasma reaction chamber is provided with a carrier gas inlet for introducing inert gas, and the carrier gas inlet is located directly below the electrode rod.
[0020] By adopting the above technical solution, after the reactive gas enters the plasma reaction chamber through the inlet pipe, the reactive gas directly contacts the electrode rod. Inert gas is introduced from the bottom of the electrode rod through the carrier gas inlet. The inert gas can push the reactive gas at the bottom to move upward to balance the concentration of the reactive gas at the bottom. At the same time, the inert gas can carry away a certain amount of heat and extend the service life of the electrode rod.
[0021] Preferably, an adjusting sleeve is rotatably installed inside the intake pipe. A through groove is formed on the outer side of the adjusting sleeve, and the through groove is arranged along the axial direction of the adjusting sleeve. A reset block is fixed to the outer circumferential surface of the adjusting sleeve. An arc-shaped groove is formed on the inner circumferential surface of the intake pipe. The reset block slides and engages with the intake pipe circumferentially through the arc-shaped groove. A reset spring is fixed to the inner wall of the arc-shaped groove, and the other end of the reset spring is fixedly connected to the side of the reset block. A clearance groove is formed on the inner top surface of the intake pipe. A limiting circular plate is vertically slidably installed on the intake pipe through the clearance groove. Two limiting blocks are fixed to the outer circumferential surface of the limiting circular plate. A limiting groove is formed on the inner wall of the clearance groove. The limiting blocks slide and engage with the intake pipe vertically through the limiting groove. A positioning groove for inserting the limiting blocks is formed on the top surface of the adjusting sleeve. A limiting spring is fixed to the top surface of the limiting circular plate, and the top end of the limiting spring is fixedly connected to the inner top surface of the clearance groove.
[0022] By adopting the above technical solution, when no reactive gas is introduced into the inlet pipe, the limiting circular plate moves downward under the elastic force of the limiting spring, and the limiting block is inserted into the positioning groove, and the through groove is not connected to the outlet hole; when reactive gas is continuously introduced into the inlet pipe, after the reactive gas in the inlet pipe is full, the limiting circular plate moves upward under the gas pressure of the reactive gas, the limiting block disengages from the positioning groove, and the adjusting sleeve rotates under the elastic force of the reset spring, so that the through groove is connected to the outlet hole, so that the reactive gas in the inlet pipe can enter the plasma reaction chamber evenly through each outlet hole.
[0023] In summary, this application includes at least one of the following beneficial technical effects: 1. The electrode rod and the gas inlet pipe are surrounded on three sides by the plasma reaction chamber. After the reactive gas is introduced from the gas inlet end of the gas inlet pipe, the reactive gas will enter the plasma reaction chamber through the gas outlet unit. Then, under the action of the electric field formed by the electrode rod and the electrode plate, it will be ionized. After the reactive gas is ionized into plasma, it will enter the furnace tube process chamber. Since the amount of gas ejected from the gas outlet unit is evenly distributed, the plasma distribution is uniform, which provides a uniform airflow environment for the subsequent thin film deposition process. Moreover, the gas inlet pipe is located on the side of the electrode rod away from the furnace tube process chamber, so that the reactive gas must be ionized before entering the furnace tube process chamber, avoiding the waste of reactive gas and ensuring ionization efficiency. 2. With a constant flow rate of the reaction gas introduced from the inlet, under the influence of gravity, the amount of gas ejected from the outlet near the inlet will be larger, while the amount of gas ejected from the outlet far from the inlet will be smaller. Since the diameter of the outlet increases from the inlet to the end of the gas pipe, the amount of gas ejected from each outlet is more uniform, which can improve the uneven plasma distribution caused by gravity and provide a uniform airflow environment for the subsequent thin film deposition process. 3. Setting the vent hole in the center of the inlet pipe near the electrode rod helps the reactant gas flow more smoothly to the vicinity of the electrode rod, allowing the reactant gas to be fully ionized when passing through the plasma reaction chamber. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of this application.
[0025] Figure 2 This is a cross-sectional view of the furnace tube body in Embodiment 1 of this application.
[0026] Figure 3 yes Figure 2 Enlarged diagram of point A in the middle.
[0027] Figure 4 This is a schematic diagram of the carrier gas inlet and electrode rod in Embodiment 1 of this application.
[0028] Figure 5 This is a schematic diagram of the intake pipe in Embodiment 1 of this application.
[0029] Figure 6 This is a schematic diagram of the air outlet unit in Embodiment 1 of this application.
[0030] Figure 7 This is a schematic diagram of the air outlet unit in Embodiment 2 of this application.
[0031] Figure 8 This is a schematic diagram of the air outlet unit in Embodiment 3 of this application.
[0032] Figure 9 This is a schematic diagram of the air outlet unit in Embodiment 4 of this application.
[0033] Figure 10 This is a schematic diagram of the intake pipe and adjusting sleeve in Embodiment 5 of this application.
[0034] Figure 11 This is a schematic diagram of the structure of the adjusting sleeve and the reset block in Embodiment 5 of this application.
[0035] Reference numerals in the attached drawings: 1. Furnace tube body; 11. Furnace tube process chamber; 2. Plasma reaction chamber; 21. Electrode rod; 22. Electrode plate; 23. Carrier gas inlet; 3. Gas inlet pipe; 31. Gas inlet end; 32. Gas pipe end; 4. Gas outlet unit; 41. Gas outlet hole; 5. Gas hole unit; 51. Gas outlet circular hole; 6. Adjusting sleeve; 61. Through groove; 62. Reset block; 63. Arc groove; 64. Reset spring; 65. Yield groove; 66. Positioning groove; 7. Limiting circular plate; 71. Limiting block; 72. Limiting groove; 73. Limiting spring. Detailed Implementation
[0036] The following is in conjunction with the appendix Figure 1-11 This application will be described in further detail.
[0037] This application discloses a plasma processing apparatus and equipment.
[0038] Example 1 Reference Figure 1 , Figure 2 and Figure 3The plasma treatment device and its equipment include a furnace tube body 1, within which a furnace tube process chamber 11 and a plasma reaction chamber 2 are disposed. Electrode rods 21 and an inlet pipe 3 are installed within the plasma reaction chamber 2, with the electrode rods 21 and inlet pipe 3 parallel to each other. The inlet pipe 3 is located on the side of the electrode rods 21 furthest from the furnace tube process chamber 11. Two electrode plates 22 are disposed within the furnace tube body 1, located on opposite sides of the electrode rods 21. The electrode plates 22 and the electrode rods 21 are separated by the wall of the plasma reaction chamber 2, which is made of quartz. The bottom end of the inlet pipe 3 is an inlet end 31 for introducing the reaction gas, and the top end of the inlet pipe 3 is a gas pipe end 32. An outlet unit 4 is disposed on the inlet pipe 3, through which the reaction gas within the inlet pipe 3 is ejected and uniformly distributed along the length of the electrode rods 21.
[0039] The electrode rod 21 and the inlet pipe 3 are surrounded on three sides by the plasma reaction chamber 2. After the reaction gas is introduced from the inlet end 31 of the inlet pipe 3, the reaction gas will enter the plasma reaction chamber 2 through the outlet unit 4. Then, under the action of the electric field formed by the electrode rod 21 and the electrode plate 22, it will be ionized. After the reaction gas is ionized into plasma, it will enter the furnace tube process chamber 11. Since the inlet pipe 3 is located on the side of the electrode rod 21 away from the furnace tube process chamber 11, the reaction gas must be ionized before it can enter the furnace tube process chamber 11, so as to avoid the waste of reaction gas and ensure ionization efficiency.
[0040] Reference Figure 4 The plasma reaction chamber 2 has a carrier gas inlet 23 at its bottom for introducing inert gas, located directly below the electrode rod 21. After the reactive gas enters the plasma reaction chamber 2 through the inlet pipe 3, it directly contacts the electrode rod 21. Inert gas is introduced from the bottom of the electrode rod 21 through the carrier gas inlet 23. The inert gas can push the reactive gas at the bottom upward to balance the concentration of the reactive gas at the bottom. At the same time, the inert gas can carry away some heat, extending the service life of the electrode rod 21.
[0041] Reference Figure 5 and Figure 6 The air outlet unit 4 includes several air outlet holes 41, which are evenly spaced along the length of the air inlet pipe 3. The diameter of the several air outlet holes 41 increases sequentially from the air inlet end 31 to the air pipe end 32, and the air outlet holes 41 are centrally located on the side of the air inlet pipe 3 near the electrode rod 21.
[0042] The implementation principle of Embodiment 1 of this application is as follows: the flow rate of the reaction gas introduced from the inlet end 31 is constant. Under the action of gravity, the amount of gas ejected from the outlet 41 closer to the inlet end 31 will be larger, while the amount of gas ejected from the outlet 41 farther away from the inlet end 31 will be smaller. Since the aperture of the outlet 41 increases sequentially from the inlet end 31 to the end of the gas pipe 32, the amount of gas ejected from each outlet 41 is more uniform, thereby improving the uneven plasma distribution caused by gravity and providing a uniform airflow environment for the subsequent thin film deposition process.
[0043] Example 2 Reference Figure 7 The difference between this embodiment and Embodiment 1 is that two sets of air outlet units 4 are provided, and the two sets of air outlet units 4 are arranged at intervals along the circumference of the air inlet pipe 3. The included angle between the two sets of air outlet units 4 is 60°, and the distances between the two sets of air outlet units 4 and the electrode rod 21 are equal.
[0044] The implementation principle of Embodiment 2 of this application is as follows: The arrangement of two sets of gas outlet units 4 makes the efficiency of the reaction gas entering the plasma reaction chamber 2 higher. After the reaction gas enters the plasma reaction chamber 2 through the two sets of gas outlet units 4, it can diffuse around the electrode rod 21. The electrode rod 21 prevents the reaction gas from directly entering the furnace tube process chamber, so that the reaction gas must pass through the ionization region formed by the electrode rod 21 and the electrode plate 22. After ionization, it can enter the furnace tube process chamber, thereby improving the ionization efficiency.
[0045] Example 3 Reference Figure 8 The difference between this embodiment and Embodiment 1 is that the air outlet unit 4 includes several sets of air hole units 5, which are evenly spaced along the length of the air inlet pipe 3. Each air hole unit 5 includes several air outlet circular holes 51 evenly spaced along the length of the air inlet pipe 3. The diameter of the air outlet circular holes 51 of the several air hole units 5 increases sequentially from the air inlet end 31 to the air pipe end 32, and the air outlet circular holes 51 are centrally located on the side of the air inlet pipe 3 closest to the electrode rod 21.
[0046] The implementation principle of Embodiment 3 of this application is as follows: Several groups of air outlet holes 51 with different hole diameters help to maintain the consistency of airflow and avoid uneven distribution of reaction gas flow. At the same time, grouping several air outlet holes 51 can improve processing convenience and reduce processing costs.
[0047] Example 4 Reference Figure 9 The difference between this embodiment and embodiment 3 is that two sets of air outlet units 4 are provided, and the two sets of air outlet units 4 are located on the side of the air inlet pipe 3 near the electrode rod 21. The included angle between the two sets of air outlet units 4 is 60°, and the distance between the two sets of air outlet units 4 and the electrode rod 21 is equal.
[0048] The implementation principle of Embodiment 4 of this application is as follows: Two sets of gas outlet units 4 are arranged on the side of the gas inlet pipe 3 near the electrode rod 21, which helps to change the time it takes for the airflow to bypass the electrode rod 21 and improve the sufficiency of the ionization of the reaction gas.
[0049] Example 5 Reference Figure 10 and Figure 11 The difference between this embodiment and Embodiment 1 is that an adjusting sleeve 6 is rotatably installed inside the intake pipe 3. A through groove 61 is formed on the outer side of the adjusting sleeve 6, and the through groove 61 is arranged along the axial direction of the adjusting sleeve 6. A reset block 62 is fixed to the outer circumferential surface of the adjusting sleeve 6, and an arc-shaped groove 63 is formed on the inner circumferential surface of the intake pipe 3. The reset block 62 slides and engages with the intake pipe 3 along its circumference through the arc-shaped groove 63. A reset spring 64 is fixed to the inner wall of the arc-shaped groove 63, and the other end of the reset spring 64 is fixedly connected to the side of the reset block 62.
[0050] Reference Figure 10 and Figure 11 The inner top surface of the intake pipe 3 is provided with a clearance groove 65, through which the intake pipe 3 slides vertically to install a limiting circular plate 7. Two limiting blocks 71 are fixed on the outer circumference of the limiting circular plate 7. A limiting groove 72 is provided on the inner wall of the clearance groove 65. The limiting blocks 71 slide vertically with the intake pipe 3 through the limiting groove 72. The top surface of the adjusting sleeve 6 is provided with a positioning groove 66 for inserting the limiting blocks 71. A limiting spring 73 is fixed on the top surface of the limiting circular plate 7, and the top end of the limiting spring 73 is fixedly connected to the inner top surface of the clearance groove 65.
[0051] The implementation principle of Embodiment 5 of this application is as follows: When no reactive gas is introduced into the inlet pipe 3, the limiting circular plate 7 moves downward under the elastic force of the limiting spring 73, and the limiting block 71 is inserted into the positioning groove 66. The through groove 61 is not connected to the outlet hole 41. Reactive gas is continuously introduced into the inlet pipe 3. After the reactive gas in the inlet pipe 3 is full, the limiting circular plate 7 moves upward under the pressure of the reactive gas. The limiting block 71 is disengaged from the positioning groove 66. The adjusting sleeve 6 rotates under the elastic force of the reset spring 64, so that the through groove 61 is connected to the outlet hole 41, so that the reactive gas in the inlet pipe 3 can enter the plasma reaction chamber 2 evenly through each outlet hole 41.
[0052] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A plasma processing device and equipment, characterized in that: The furnace tube body (1) includes a furnace tube process chamber (11) and a plasma reaction chamber (2) inside the furnace tube body (1). An inlet pipe (3) and an electrode rod (21) are installed inside the plasma reaction chamber (2). The inlet pipe (3) is located on the side of the electrode rod (21) away from the furnace tube process chamber (11). Two electrode plates (22) are installed inside the furnace tube body (1). The two electrode plates (22) are located on both sides of the electrode rod (21). The bottom end of the inlet pipe (3) is an inlet end (31) for introducing reaction gas. The top end of the inlet pipe (3) is a gas pipe end (32). An outlet unit (4) is provided on the inlet pipe (3). The reaction gas in the inlet pipe (3) is ejected through several outlet units (4) and evenly distributed along the length direction of the electrode rod (21).
2. The plasma processing device and equipment according to claim 1, characterized in that: The air outlet unit (4) includes a plurality of air outlet holes (41), which are equally spaced along the length of the air inlet pipe (3), and the diameter of the plurality of air outlet holes (41) increases sequentially from the air inlet end (31) to the end of the air pipe (32).
3. The plasma processing device and equipment according to claim 2, characterized in that: The air outlet (41) is located in the center of the air inlet pipe (3) on the side near the electrode rod (21).
4. The plasma processing apparatus and equipment according to claim 2, characterized in that: The air outlet unit (4) is provided in two sets. The two sets of air outlet units (4) are arranged at intervals along the circumference of the air inlet pipe (3). The included angle between the two sets of air outlet units (4) is no greater than 60°. The distance between the two sets of air outlet units (4) and the electrode rod (21) is equal.
5. The plasma processing apparatus and equipment according to claim 1, characterized in that: The air outlet unit (4) includes several sets of air hole units (5). The several air hole units (5) are arranged at equal intervals along the length direction of the air inlet pipe (3). The air hole unit (5) includes several air outlet round holes (51) arranged at equal intervals along the length direction of the air inlet pipe (3). The diameter of the air outlet round holes (51) of the several air hole units (5) increases sequentially from the air inlet end (31) to the end of the air pipe (32).
6. The plasma processing apparatus and equipment according to claim 5, characterized in that: The air outlet hole (51) is located in the center of the air inlet pipe (3) on the side near the electrode rod (21).
7. The plasma processing apparatus and equipment according to claim 5, characterized in that: The air outlet unit (4) is provided in two sets. The two sets of air outlet units (4) are located on the side of the air inlet pipe (3) close to the electrode rod (21). The included angle between the two sets of air outlet units (4) is no greater than 60°, and the distance between the two sets of air outlet units (4) and the electrode rod (21) is equal.
8. The plasma processing apparatus and equipment according to claim 1, characterized in that: The bottom of the plasma reaction chamber (2) is provided with a carrier gas inlet (23) for introducing inert gas, and the carrier gas inlet (23) is located directly below the electrode rod (21).
9. A plasma processing apparatus and device according to claim 2, characterized in that: An adjusting sleeve (6) is rotatably installed inside the air intake pipe (3). A through groove (61) is provided on the outer side of the adjusting sleeve (6). The through groove (61) is arranged along the axial direction of the adjusting sleeve (6). A reset block (62) is fixed on the outer circumferential surface of the adjusting sleeve (6). An arc groove (63) is provided on the inner circumferential surface of the air intake pipe (3). The reset block (62) slides and engages with the air intake pipe (3) along its circumferential direction through the arc groove (63). A reset spring (64) is fixed on the inner wall of the arc groove (63). The other end of the reset spring (64) is fixedly connected to the side of the reset block (62). The inner top surface of the air intake pipe (3) is opened A clearance groove (65) is provided, and the intake pipe (3) slides vertically through the clearance groove (65) to install a limiting circular plate (7). Two limiting blocks (71) are fixed on the outer circumferential surface of the limiting circular plate (7). A limiting groove (72) is opened on the inner wall of the clearance groove (65). The limiting block (71) slides vertically with the intake pipe (3) through the limiting groove (72). A positioning groove (66) for inserting the limiting block (71) is opened on the top surface of the adjusting sleeve (6). A limiting spring (73) is fixed on the top surface of the limiting circular plate (7). The top end of the limiting spring (73) is fixedly connected to the inner top surface of the clearance groove (65).