Ion sheath closed-loop regulated atomic layer etching apparatus and process

Abstract

The application relates to the technical field of wafer etching, in particular to an ion sheath closed-loop regulated atomic layer etching device and process, which comprises a device main body, one side surface of the device main body is provided with a sealing door, the inner bottom surface of the device main body is provided with an electrostatic chuck, the upper surface of the electrostatic chuck is provided with array-distributed convex points, the periphery of the electrostatic chuck is provided with a ventilation ring, a lifting mechanism is arranged between the ventilation ring and the inner bottom surface of the device main body, the inner surface of the ventilation ring is provided with an annular port, the upper surface of the ventilation ring is fixedly provided with a plurality of connecting boxes arranged in an annular array, the inner side of the connecting box is fixedly embedded with a guide box, and the inner side of the guide box is slidably inserted with a sliding shell through a first elastic mechanism. The application combines the functions of the near-field electrostatic removal of the contact pin, the edge air floating lifting and the wafer desorption, the contact pin can be stored and sealed, the sealing ring can control the air, the etching environment can be effectively stabilized, and the desorption efficiency and the machining precision are improved.

Description

Technical Field

[0001] This invention relates to the field of wafer etching technology, and in particular to an atomic layer etching apparatus and process with closed-loop control of an ion sheath. Background Technology

[0002] Atomic layer etching (ALE), a high-precision and highly selective micro-nano fabrication technology, is widely used in semiconductor chip manufacturing. In ALE, wafers are typically positioned using electrostatic chucks to ensure close contact between the wafer and the chuck surface during etching, preventing a decrease in etching precision due to wafer displacement. However, after etching, a large amount of residual electrostatic charge is generated on the wafer surface due to plasma etching, making it difficult for the wafer to detach from the electrostatic chuck.

[0003] Currently, even if some existing equipment is equipped with air blowing or electrostatic elimination structures, the air jet positions of some air blowing structures are improperly set, with the air jet direction directly aimed at the wafer etching functional area. This not only interferes with the plasma distribution and ion sheath morphology during the etching process, leading to a decrease in etching uniformity, but may also blow the particles generated during etching onto the wafer surface, causing surface contamination. Some electrostatic elimination components adopt an exposed design, which can interfere with the electric field distribution inside the cavity during the etching process, causing problems such as ion sheath distortion and partial discharge, damaging the etching process environment, and thus affecting etching accuracy and process stability. Therefore, an atomic layer etching device and process with closed-loop control of the ion sheath is proposed. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the prior art by proposing an atomic layer etching device and process with closed-loop control of an ion sheath.

[0005] To achieve the above objectives, the technical solution adopted by this invention is as follows: an atomic layer etching device with closed-loop control of an ion sheath, comprising a device body, a sealing door provided on one side surface of the device body, an electrostatic chuck provided on the inner bottom surface of the device body, an array of protrusions provided on the upper surface of the electrostatic chuck, a venting ring provided around the electrostatic chuck, a lifting mechanism provided between the venting ring and the inner bottom surface of the device body, an annular opening provided on the inner surface of the venting ring, and a plurality of connecting boxes arranged in an annular array fixedly provided on the upper surface of the venting ring. A guide box is fixedly embedded inside the connecting box. A sliding shell is slidably inserted into the inside of the guide box through a first elastic mechanism. An L-shaped plate is slidably inserted into the inside of the sliding shell through a second elastic mechanism. One end of the L-shaped plate near the electrostatic chuck passes through the sliding shell and is rotatably connected to a contact pin. The surface of the contact pin is provided with a curved part. A sealing ring is connected to the port of the annular opening through a vertical movement mechanism. Several air jet holes arranged in an annular array are opened through the outer surface of the sealing ring. A pushing part is provided on the upper side of the sealing ring corresponding to the position of each connecting box. The vent ring is used to introduce pressurized gas. Under the action of pressurized gas, the sliding shell slides relative to the guide box, and the L-shaped plate slides relative to the sliding shell at the same time. The sliding shell moves downward and abuts against the pushing part, driving the sealing ring to move downward, so that the jet hole and the annular opening are connected to each other.

[0006] Preferably, an air inlet pipe is fixedly connected to the lower surface edge of the vent ring, and the lower end of the air inlet pipe slides through the inner bottom surface of the main body of the device.

[0007] Preferably, the lifting mechanism includes guide columns and lifting cylinders fixedly connected to both sides of the lower surface, the lower end of the guide column slidingly penetrating the inner bottom surface of the main body of the device, and a protective shell fixedly provided on the outer surface of the lifting cylinder, the protective shell being fixedly embedded in the lower surface of the main body of the device.

[0008] Preferably, the first elastic mechanism includes a sliding opening on the upper surface of the guide box, a slider is fixedly connected to the upper surface of the sliding shell, the slider slides into the inner side of the sliding opening, a first guide rod is fixedly connected to the inner wall of the sliding opening, the first guide rod slides through the inner side of the slider, a first return spring is sleeved on the outer surface of the first guide rod, and the first return spring is located on the side of the slider close to the electrostatic chuck.

[0009] Preferably, the second elastic mechanism includes a limiting groove formed on the top surface of the sliding shell, the upper end of the L-shaped plate is slidably inserted into the inner side of the limiting groove, a second guide rod is fixedly connected to the inner side of the sliding shell, the second guide rod slides through the inner side of the L-shaped plate, and a second return spring is sleeved on the outer surface of the second guide rod, the second return spring being located on the side of the L-shaped plate near the electrostatic chuck.

[0010] Preferably, one end of the L-shaped plate has a notch, one end of the stylus is connected to an adapter post, both ends of the adapter post are fixedly connected to a rotating shaft, the rotating shaft is rotatably fitted into the inner wall of the notch, and the inner bottom edge of the notch is fixedly provided with a limiting slope.

[0011] Preferably, the pushing part includes a contact block fixedly connected to the upper side of the sealing ring, the outer surface of the contact block and the side corresponding to the stylus are provided with a through port, the inner surface of the venting ring and the lower part corresponding to the connection box port are fixedly connected with a transition block, and the lower surface of the sliding shell is provided with an inclined guide surface.

[0012] Preferably, the vertical movement mechanism includes a bent edge fixedly connected to the lower side of the sealing ring, a T-shaped post slidably passing through the lower surface of the bent edge, the upper end of the T-shaped post being fixedly connected to the lower surface of the annular opening, and a tension spring being sleeved on the outer surface of the T-shaped post, with the upper and lower ends of the tension spring being fixedly connected to the surfaces of the annular opening and the bent edge, respectively.

[0013] An atomic layer etching process with closed-loop control of an ion sheath, using the aforementioned etching equipment, includes the following steps: S1. Place the wafer on the surface of the electrostatic chuck, turn on the electrostatic chuck for adsorption and positioning, and control the venting ring to move down to below the height of the electrostatic chuck through the lifting mechanism. S2. Perform plasma etching, and turn off the electrostatic chuck after etching is complete; S3. The lifting mechanism controls the ventilation ring to move upward and reset, and pressurizes the ventilation ring with air. The L-shaped plate and the sliding shell slide respectively. The stylus moves out of the guide box and rotates downward under gravity, and then moves to the edge of the wafer to eliminate the residual static electricity of the wafer. At the same time, after the sealing ring moves downward, the air jet blows out gas to help the wafer get off the electrostatic chuck. S4. Remove the wafer.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention forms a near-field discharge channel through a stylus, effectively eliminating residual static charge on the wafer surface, fundamentally solving the problem of wafers being difficult to detach from electrostatic chucks after etching, and ensuring smooth operation of subsequent processes; 2. This invention sprays air onto the lower edge of the wafer surface, avoiding the wafer etching functional area, generating an air-floating lifting force to assist the wafer in detaching from the electrostatic chuck and improving the desorption efficiency. 3. The probe of this invention can be retracted and hidden, avoiding interference with the electric field distribution inside the cavity due to the exposed design, preventing problems such as ion sheath distortion and partial discharge, and ensuring a stable etching process environment; 4. The sealing ring of this invention can seal the annular opening during the etching process, preventing gas from entering and interfering with the etching process, thereby further improving the stability and precision of the etching process. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of an atomic layer etching device with closed-loop control of an ion sheath according to the present invention; Figure 2 This is a cross-sectional view of an atomic layer etching apparatus with closed-loop control of an ion sheath according to the present invention. Figure 3 This invention relates to an atomic layer etching apparatus with closed-loop control of an ion sheath. Figure 2 Enlarged view of point A in the middle; Figure 4 This invention relates to an atomic layer etching apparatus with closed-loop control of an ion sheath. Figure 3 Enlarged view at point B in the middle; Figure 5 This is a cross-sectional view of the guide box of an atomic layer etching apparatus with closed-loop control of an ion sheath according to the present invention. Figure 6This is a schematic diagram of the ventilation ring of an atomic layer etching apparatus with closed-loop control of an ion sheath according to the present invention. Figure 7 This is a schematic diagram of the sealing ring of an atomic layer etching apparatus with closed-loop control of an ion sheath according to the present invention; Figure 8 This is a partial cross-sectional view of the gas ring of an atomic layer etching apparatus with closed-loop control of an ion sheath according to the present invention, during gas filling.

[0016] The components include: 1. Main body of the device; 2. Electrostatic chuck; 3. Ventilation ring; 4. Lifting cylinder; 5. Protective shell; 6. Guide post; 7. Air inlet pipe; 8. Annular opening; 9. Connecting box; 10. Guide box; 11. Sliding shell; 12. Sliding port; 13. Sliding block; 14. First guide rod; 15. First return spring; 16. L-shaped plate; 17. Limiting groove; 18. Second guide rod; 19. Second return spring; 20. Notch; 21. Adapter post; 22. Rotating shaft; 23. Limiting slope; 24. Contact pin; 25. Bending part; 26. Sealing ring; 27. Bending edge; 28. T-shaped post; 29. ​​Tension spring; 30. Contact block; 31. Through port; 32. Transition block; 33. Air jet hole; 34. Sloping guide surface; 35. Protrusion; 36. Sealing door. Detailed Implementation

[0017] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0018] like Figures 1-8 The atomic layer etching (ALE) apparatus shown includes a main body 1. A sealing door 36 is provided on one side surface of the main body 1. The main body 1 is a closed process chamber of an existing semiconductor atomic layer etching (ALE) apparatus, a mature equipment structure, used to provide a plasma reaction environment. An electrostatic chuck 2 is provided on the inner bottom surface of the main body 1. An array of protrusions 35 is provided on the upper surface of the electrostatic chuck 2. A venting ring 3 is provided around the electrostatic chuck 2. A lifting mechanism is provided between the venting ring 3 and the inner bottom surface of the main body 1. An annular opening 8 is provided on the inner surface of the venting ring 3. Several connecting boxes 9 arranged in an annular array are fixedly provided on the upper surface of the venting ring 3. A guide box 10 is fixedly embedded in the inner side of the connecting box 9. A guide box 10 is slidably inserted into the inner side of the guide box 10 through a first elastic mechanism. The sliding shell 11 has an L-shaped plate 16 slidably inserted into its inner side via a second elastic mechanism. The end of the L-shaped plate 16 near the electrostatic chuck 2 passes through the sliding shell 11 and is rotatably connected to a contact pin 24. The surface of the contact pin 24 is provided with a curved part 25. The port of the annular opening 8 is connected to a sealing ring 26 via a vertical movement mechanism. The outer surface of the sealing ring 26 is provided with a plurality of air jet holes 33 arranged in an annular array. The upper side of the sealing ring 26 is provided with a pushing part corresponding to the position of each connecting box 9. The vent ring 3 is used to introduce pressurized gas. Under the action of pressurized gas, the sliding shell 11 slides relative to the guide box 10, while the L-shaped plate 16 slides relative to the sliding shell 11. The sliding shell 11 moves downward and comes into contact with the pushing part, driving the sealing ring 26 to move downward, so that the jet hole 33 and the annular opening 8 are connected to each other.

[0019] The electrostatic chuck 2 uses a JR force electrostatic chuck, a core component of semiconductor ALE etching equipment. It can strongly adsorb and fix wafers in a low-pressure environment. By applying a reverse voltage to neutralize residual charge, combined with optimized structural design, it meets the stable clamping and thermal conductivity requirements of large-size wafers. The surface is covered with a high-density three-dimensional thermally conductive bump array 35, which is isolated from the wafer and forms a uniform micro-gap. To facilitate subsequent wafer unloading, the corresponding edge areas of the wafer are usually not covered with bumps 35, which has no adverse effect under conventional ALE etching processes and is a common and reasonable design in the industry.

[0020] An air inlet pipe 7 is fixedly connected to the lower edge of the venting ring 3, and the lower end of the air inlet pipe 7 slides through the inner bottom surface of the main body 1 of the device. The connection between the air inlet pipe 7 and the venting ring 3 can be sealed with a sealing gasket to effectively prevent high-pressure gas leakage. A sliding sealing sleeve is provided at the part of the air inlet pipe 7 that passes through the main body 1 of the device, which not only does not hinder the synchronous movement of the air inlet pipe 7 with the venting ring 3, but also isolates the etching gas inside the cavity from the external environment.

[0021] The lifting mechanism includes guide posts 6 and lifting cylinders 4 fixedly connected to both sides of the lower surface. The lower end of the guide post 6 slides through the inner bottom surface of the main body 1 of the device. A protective shell 5 is fixedly installed on the outer surface of the lifting cylinder 4 and is fixedly embedded in the lower surface of the main body 1 of the device. The guide post 6 can ensure a smooth lifting process and avoid deviation that affects the wafer positioning accuracy.

[0022] The first elastic mechanism includes a sliding opening 12 formed on the upper surface of the guide box 10. A slider 13 is fixedly connected to the upper surface of the sliding shell 11. The slider 13 slides into the inner side of the sliding opening 12. A first guide rod 14 is fixedly connected to the inner wall of the sliding opening 12. The first guide rod 14 slides through the inner side of the slider 13. A first return spring 15 is sleeved on the outer surface of the first guide rod 14. The first return spring 15 is located on the side of the slider 13 closest to the electrostatic chuck 2. The first guide rod 14 serves to limit and guide the slider 13, and also guides the first return spring 15 to prevent deformation and displacement.

[0023] The second elastic mechanism includes a limiting groove 17 formed on the inner top surface of the sliding shell 11. The upper end of the L-shaped plate 16 slides into the inner side of the limiting groove 17, thereby limiting the movement trajectory of the L-shaped plate 16 and preventing deviation and shaking. A second guide rod 18 is fixedly connected to the inner side of the sliding shell 11. The second guide rod 18 slides through the inner side of the L-shaped plate 16 to ensure smooth sliding. A second return spring 19 is sleeved on the outer surface of the second guide rod 18. The second return spring 19 is located on the side of the L-shaped plate 16 closest to the electrostatic chuck 2. The elastic force of the second return spring 19 is used to complete the springback and reset of the L-shaped plate 16.

[0024] A notch 20 is provided at one end of the L-shaped plate 16, and an adapter post 21 is attached vertically to one end of the stylus 24. The notch 20 is adapted to the installation requirements of the adapter post 21. A rotating shaft 22 is fixedly connected to both ends of the adapter post 21. The rotating shaft 22 is rotatably fitted into the inner wall of the notch 20, allowing the adapter post 21 and the moving stylus 24 to rotate flexibly. A limiting slope 23 is fixedly provided on the inner bottom edge of the notch 20. The limiting slope 23 is inclined and can limit the rotation angle of the stylus 24 to prevent the stylus 24 from deflecting excessively and affecting its use.

[0025] The pushing part includes a contact block 30 fixedly connected to the sealing ring 26, which moves synchronously with the sealing ring 26. A passage 31 is provided on the outer surface of the contact block 30 and on the side corresponding to the stylus 24. The size of the passage 31 is adapted to the stylus 24 to ensure that the stylus 24 can pass through smoothly without jamming. A transition block 32 is fixedly connected to the inner surface of the vent ring 3 and below the port of the connecting box 9. A sloping guide surface 34 is provided on the front of the lower surface of the sliding shell 11. The sloping guide surface 34 is smoothly inclined to reduce the frictional resistance when it contacts the contact block 30 and ensures that the pushing action is smooth and stable.

[0026] The vertical movement mechanism includes a bent edge 27 fixedly connected to the lower side of the sealing ring 26. A T-shaped post 28 slides through the lower surface of the bent edge 27. The upper end of the T-shaped post 28 is fixedly connected to the lower surface of the annular opening 8. The T-shaped post 28 plays a vertical limiting and guiding role for the bent edge 27 to prevent displacement. A tension spring 29 is sleeved on the outer surface of the T-shaped post 28. The upper and lower ends of the tension spring 29 are fixedly connected to the surfaces of the annular opening 8 and the bent edge 27, respectively. The tension spring 29 can drive the sealing ring 26 to complete vertical reset through its own tension, ensuring that the vertical movement is precise and controllable.

[0027] An atomic layer etching process with closed-loop control of an ion sheath, using the aforementioned etching equipment, includes the following steps: S1. Place the wafer on the surface of the electrostatic chuck 2, turn on the electrostatic chuck 2 for adsorption and positioning, and control the venting ring 3 to move down to below the height of the electrostatic chuck 2 through the lifting mechanism. S2. Perform plasma etching, and turn off the electrostatic chuck 2 after etching is complete; S3, the lifting mechanism controls the ventilation ring 3 to move up and reset, and pressurizes the ventilation ring 3 with air. The L-shaped plate 16 and the sliding shell 11 slide respectively. The stylus 24 moves out of the inner side of the guide box 10 and rotates downward under gravity, and then moves to the edge of the wafer to eliminate the residual static electricity of the wafer. At the same time, after the sealing ring 26 moves down, the jet hole 33 blows out gas to help the wafer get off the electrostatic chuck 2. S4. Remove the wafer.

[0028] During use, high-pressure gas is introduced through the air inlet pipe 7, pressurizing the vent ring 3. This pressurization causes the sliding shell 11 to move under the pressure of the gas, and the slider 13 slides along the inner side of the sliding opening 12, compressing the first return spring 15. Simultaneously, the L-shaped plate 16 also moves under the pressure of the gas, compressing the second return spring 19. This synchronous movement causes the stylus 24 to extend out of the guide box 10. As the stylus 24 extends, the curved part 25 is guided by the transition block 32 and passes through the inner side of the through-hole 31. Then, under the influence of gravity, the stylus 24 rotates downwards about the pivot 22 until it is blocked and limited by the limiting slope 23. Due to the presence of the curved part 25, the lower end of the stylus 24 is in a horizontal state at this point. As the sliding shell 11 and the L-shaped plate 16 continue to move, the lower end of the stylus 24 reaches below the edge of the wafer, at which point the state is as follows. Figure 8 This illustrates the formation of a near-field discharge channel to eliminate residual static electricity on the wafer, thereby assisting in subsequent wafer desorption.

[0029] As the sliding shell 11 moves, the inclined guide surface 34 pushes against the contact block 30, causing the sealing ring 26 to move downward under the pushing force, which in turn causes the tension spring 29 to be pulled. After the sealing ring 26 moves downward, the jet hole 33 is aligned with the annular opening 8. The high-pressure gas in the annular opening 8 is ejected through the jet hole 33, and the airflow acts on the edge of the lower surface of the wafer, forming an upward air buoy lifting force to help the wafer detach from the electrostatic chuck 2.

[0030] After the air intake pipe 7 stops filling, the slider 13 moves to its reset position under the elastic force of the first reset spring 15, and the L-shaped plate 16 moves to its reset position under the elastic force of the second reset spring 19. The bent part 25 passes through the surface of the through port 31 and the transition block 32 and reaches the inner side of the connecting box 9, achieving the function of receiving protection. This effectively avoids the direct bombardment of high-energy ions, the strong scouring of etching gas, and the erosion of plasma sputtering during the etching process. At the same time, it shrinks and hides the conductive contact pin 24 component to prevent the contact pin 24 from being exposed and interfering with the electric field distribution and ion sheath control environment in the cavity, ensuring that the etching process is stable and unaffected. Under the tension of the tension spring 29, the sealing ring 26 moves upward to its reset position, and the jet hole 33 moves above the annular opening 8, so that the annular opening 8 is sealed, preventing gas from entering during the etching process and ensuring the stable progress of the etching process.

[0031] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. An atomic layer etching apparatus with closed-loop control of an ion sheath, comprising a main body (1), wherein a sealing door (36) is provided on one side surface of the main body (1), characterized in that: An electrostatic chuck (2) is provided on the inner bottom surface of the main body (1) of the device. An array of protrusions (35) is provided on the upper surface of the electrostatic chuck (2). A ventilation ring (3) is provided around the electrostatic chuck (2). A lifting mechanism is provided between the ventilation ring (3) and the inner bottom surface of the main body (1). An annular opening (8) is provided on the inner surface of the ventilation ring (3). Several connecting boxes (9) arranged in an annular array are fixedly provided on the upper surface of the ventilation ring (3). A guide box (10) is fixedly embedded in the inner side of the connecting box (9). The inner side of the guide box (10) is slidably inserted through a first elastic mechanism. The device is equipped with a sliding shell (11). An L-shaped plate (16) is slidably inserted into the inner side of the sliding shell (11) through a second elastic mechanism. The end of the L-shaped plate (16) near the electrostatic chuck (2) passes through the sliding shell (11) and is rotatably connected to a stylus (24). The surface of the stylus (24) is provided with a curved part (25). A sealing ring (26) is connected to the port of the annular opening (8) through a vertical movement mechanism. A number of air jet holes (33) arranged in an annular array are opened through the outer surface of the sealing ring (26). A pushing part is provided on the upper side of the sealing ring (26) corresponding to the position of each connecting box (9). The ventilation ring (3) is used to introduce pressurized gas. Under the action of pressurized gas, the sliding shell (11) slides relative to the guide box (10), and at the same time, the L-shaped plate (16) slides relative to the sliding shell (11). The sliding shell (11) moves down and abuts against the pushing part, driving the sealing ring (26) to move downward, so that the jet hole (33) and the annular opening (8) are connected to each other.

2. The atomic layer etching apparatus with closed-loop control of an ion sheath according to claim 1, characterized in that: An air inlet pipe (7) is fixedly connected to the lower surface edge of the ventilation ring (3), and the lower end of the air inlet pipe (7) slides through the inner bottom surface of the main body (1) of the device.

3. The atomic layer etching apparatus with closed-loop control of an ion sheath according to claim 1, characterized in that: The lifting mechanism includes a guide column (6) and a lifting cylinder (4) fixedly connected to both sides of the lower surface. The lower end of the guide column (6) slides through the inner bottom surface of the main body (1) of the device. A protective shell (5) is fixedly installed on the outer surface of the lifting cylinder (4). The protective shell (5) is fixedly embedded in the lower surface of the main body (1) of the device.

4. The atomic layer etching apparatus with closed-loop control of an ion sheath according to claim 1, characterized in that: The first elastic mechanism includes a sliding opening (12) on the upper surface of the guide box (10). A slider (13) is fixedly connected to the upper surface of the sliding shell (11). The slider (13) slides into the inner side of the sliding opening (12). A first guide rod (14) is fixedly connected to the inner wall of the sliding opening (12). The first guide rod (14) slides through the inner side of the slider (13). A first reset spring (15) is sleeved on the outer surface of the first guide rod (14). The first reset spring (15) is located on the side of the slider (13) close to the electrostatic chuck (2).

5. The atomic layer etching apparatus with closed-loop control of an ion sheath according to claim 1, characterized in that: The second elastic mechanism includes a limiting groove (17) opened on the top surface of the sliding shell (11). The upper end of the L-shaped plate (16) is slidably inserted into the inner side of the limiting groove (17). A second guide rod (18) is fixedly connected to the inner side of the sliding shell (11). The second guide rod (18) slides through the inner side of the L-shaped plate (16). A second reset spring (19) is sleeved on the outer surface of the second guide rod (18). The second reset spring (19) is located on the side of the L-shaped plate (16) close to the electrostatic chuck (2).

6. The atomic layer etching apparatus with closed-loop control of an ion sheath according to claim 1, characterized in that: One end of the L-shaped plate (16) is provided with a notch (20), one end of the stylus (24) is connected to a connecting post (21), and the two ends of the connecting post (21) are respectively fixedly connected to a rotating shaft (22). The rotating shaft (22) is rotatably fitted into the inner wall of the notch (20), and the inner bottom edge of the notch (20) is fixedly provided with a limiting slope (23).

7. The atomic layer etching apparatus with closed-loop control of an ion sheath according to claim 1, characterized in that: The pushing part includes a contact block (30) fixedly connected to the upper side of the sealing ring (26). The outer surface of the contact block (30) and the side corresponding to the stylus (24) are provided with a passage (31). The inner surface of the venting ring (3) and the lower part of the port of the connecting box (9) are fixedly connected with a transition block (32). The lower surface of the sliding shell (11) is provided with a sloping guide surface (34).

8. The atomic layer etching apparatus with closed-loop control of an ion sheath according to claim 1, characterized in that: The vertical movement mechanism includes a bent edge (27) fixedly connected to the lower side of the sealing ring (26). A T-shaped post (28) slides through the lower surface of the bent edge (27). The upper end of the T-shaped post (28) is fixedly connected to the lower surface of the annular opening (8). A tension spring (29) is sleeved on the outer surface of the T-shaped post (28). The upper and lower ends of the tension spring (29) are fixedly connected to the surfaces of the annular opening (8) and the bent edge (27), respectively.

9. An atomic layer etching process with closed-loop control of an ion sheath, performed using the etching equipment described in any one of claims 1-8, characterized in that: Includes the following steps: S1. Place the wafer on the surface of the electrostatic chuck (2), turn on the electrostatic chuck (2) for adsorption and positioning, and control the ventilation ring (3) to move down to below the height of the electrostatic chuck (2) through the lifting mechanism. S2. Perform plasma etching, and turn off the electrostatic chuck after etching is complete (2). S3. The lifting mechanism controls the ventilation ring (3) to move up and reset, and pressurizes the ventilation ring (3). The L-shaped plate (16) and the sliding shell (11) slide respectively. The stylus (24) moves out of the inner side of the guide box (10) and rotates downward under gravity, and then moves to the edge of the wafer to eliminate the residual static electricity of the wafer. At the same time, after the sealing ring (26) moves down, the jet hole (33) blows out gas to help the wafer get off the electrostatic chuck (2). S4. Remove the wafer.

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