Plasma etching device, etching machine, focus ring and jacking structure for focus ring

Abstract

A plasma etching device, an etching machine, a focus ring (10) and a jacking structure for the focus ring (10). The focus ring (10) comprises a plurality of ring bodies which are stacked; the ring bodies are arranged independent of each other; and the axial dimension of the ring body (1) located on the uppermost layer is greater than the allowed maximum jacking height of the focus ring (10). According to the split focus ring (10), the ring bodies can all be jacked during use, so that a large space below the focus ring (10) after the whole original focus ring (10) is jacked is divided into a plurality of small spaces by means of the ring bodies; and the small spaces are connected only by means of fine gaps between structures, and the concentration and activity of charged particles of plasmas in the small spaces are limited, thereby achieving the purposes of preventing arc discharge and avoiding ignition marks or the fragmentation of the focus ring (10).

Description

Plasma etching equipment, etching machine, focusing ring and lifting structure thereof

[0001] This application claims priority from the following Chinese patent application, the entire contents of which are incorporated herein by reference: Application Number: 202310976696.0, Filing Date: August 3, 2023, Applicant: Jiangsu Leuven Instrument Co., Ltd., Invention Title: Plasma Etching Equipment, Etching Machine, Focus Ring, and Lifting Structure Thereof. Technical Field

[0002] The present invention relates to the technical field of semiconductor processing equipment, and in particular to a plasma etching device, an etching machine, a focusing ring and a lifting structure thereof. Background Art

[0003] With the development of semiconductor devices, wafer pattern precision has become increasingly higher, and a series of dry etching technologies have gradually been developed. Among them, inductively coupled plasma etching (ICP) is a plasma etching technology for processing micro-nanostructures. It has the advantages of fast etching speed, high selectivity, high anisotropy, minimal etching damage, high cross-sectional profile controllability, and high etched surface flatness, and is currently widely used.

[0004] The etching in the ICP device occurs in a vacuum reaction chamber. The electrostatic adsorption chuck is placed on a base in the middle of the vacuum reaction chamber. The wafer is located on the upper surface of the electrostatic adsorption chuck, and a focusing ring is installed around the wafer to change the distribution and morphology of the plasma sheath in the edge area of ​​the wafer.

[0005] When the focus ring is exposed to a plasma filled with etching gas for extended periods, the material on its upper surface is consumed, and its height decreases accordingly. This decrease in focus ring height can lead to a series of changes in etching parameters. The most serious impact is a tilted etch path at the wafer edge, which reduces etch uniformity. In established existing technologies, raising the focus ring to compensate for the amount of etching is an effective method.

[0006] When the focus ring is lifted, a certain amount of space is created at the bottom, as shown in Figure 1. As manufacturing processes continue to advance, the height of the focus ring is constantly increasing, and the space at the bottom is constantly increasing. This has brought a new problem: arc discharge is very likely to occur in the excessive space at the bottom of the focus ring, generating high heat instantly. In mild cases, it will cause sparks on the surface, and in severe cases, it can cause the focus ring to break.

[0007] Summary of the Invention

[0008] The first purpose of the present invention is to provide a focusing ring so that it can avoid arc discharge caused by excessive space at the bottom of the focusing ring after it is lifted, thereby avoiding the problem of sparks or focus ring breakage.

[0009] The second object of the present invention is to provide a focusing ring lifting structure matched with the above-mentioned focusing ring, as well as a plasma etching device and an etching machine equipped with the above-mentioned focusing ring and its lifting structure.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] A focusing ring comprises a plurality of stacked ring bodies, wherein the ring bodies are independently arranged, and the axial dimension of the ring body located at the uppermost layer is greater than the maximum lifting height allowed by the focusing ring.

[0012] Optionally, the axial dimension of the ring body located at the uppermost layer is larger than the axial dimensions of the remaining ring bodies.

[0013] Optionally, the axial dimensions of the ring bodies except the ring body located at the uppermost layer are the same.

[0014] Optionally, the mating surface between two adjacent ring bodies is an annular plane or a concave-convex surface.

[0015] Optionally, the mating surface between two adjacent ring bodies is an annular plane perpendicular to the axis of the ring body.

[0016] Optionally, the mating surface between two adjacent ring bodies is a curved surface; or, the mating surface between two adjacent ring bodies is a zigzag surface; or, the mating surface between two adjacent ring bodies is a combination of at least two of a plane, a curved surface and a zigzag surface.

[0017] Optionally, one of the mating surfaces between two adjacent ring bodies includes a first annular boss and a first annular groove alternately arranged along the radial direction of the ring body, and the other mating surface between the two adjacent ring bodies includes a second annular boss and a second annular groove alternately arranged along the radial direction of the ring body, the first annular boss is embedded in the second annular groove, and the second annular boss is embedded in the first annular groove.

[0018] Optionally, the mating surface between two adjacent ring bodies includes a plurality of annular abutment surfaces arranged in a ring-like manner along the radial direction of the ring body, and each of the annular abutment surfaces is arranged in sequence and spaced apart in a step-like manner along the axial direction of the ring body.

[0019] Optionally, the ring body located at the uppermost layer is made of one of SiO2, Si, SiC and Y2O3, and the remaining ring bodies are made of SiO2 or Al2O3.

[0020] A focusing ring lifting structure, used for lifting a focusing ring as described in any one of the above items, the focusing ring lifting structure includes a driving unit and a plurality of executing units, the driving unit is transmission-connected to each of the executing units, each of the executing units is arranged in a one-to-one correspondence with each ring body of the focusing ring, and the driving unit of the focusing ring lifting structure is used to drive each of the executing units to lift each of the ring bodies of the focusing ring to a preset height according to preset instructions.

[0021] Optionally, the focusing ring lifting structure includes:

[0022] an ejector component, the ejector component comprising a plurality of ejectors correspondingly and transmission-connected to the respective ring bodies of the focusing ring;

[0023] a variable pitch transmission mechanism comprising a pitch-changing plate and transmission rods, a transmission structure disposed on the pitch-changing plate and correspondingly engaging with each of the transmission rods, the transmission rods being in transmission connection with the ejector pins, the ends of the transmission rods distal from the ejector pins engaging with the transmission structure, the transmission ratios of the transmission structures decreasing in equal proportion to the arrangement order of the corresponding ring bodies from top to bottom within the focusing ring;

[0024] a positioning member, the positioning member being used to guide and position each of the ejector pins and / or the transmission rod so as to enable each of the ejector pins to reciprocate along the axial direction of the focus ring;

[0025] A driving device is used to drive the pitch-variable plate to move back and forth along a preset direction.

[0026] Optionally, the transmission structure is a pitch-varying slot, a follower shaft is provided at the bottom of the transmission rod, the axis of the follower shaft intersects with the axis of the transmission rod, the follower shaft and the pitch-varying slot are slidably fitted, and the angle between the line connecting the two ends of the pitch-varying slot and the horizontal plane is reduced in proportion according to the arrangement order of the corresponding ring bodies from top to bottom in the focusing ring.

[0027] Optionally, the positioning component is provided with a guide hole and a guide groove connected to the guide hole, the transmission rod is slidably engaged with the guide hole, and the follower shaft extends from the guide groove to contact and engage with the pitch change slot.

[0028] Optionally, the transmission structure is a pitch-variable inclined plane, and the angle between the pitch-variable inclined plane and the horizontal plane decreases in equal proportion according to the arrangement order of the corresponding ring bodies from top to bottom in the focusing ring.

[0029] Optionally, the focus ring lifting structure further includes a fixing seat, and the pitch variable plate is disposed on the fixing seat so as to be reciprocatingly movable along an axial direction perpendicular to the focus ring.

[0030] Optionally, a slider is provided on one of the fixed seat and the pitch variable plate, and a guide rail is provided on the other of the fixed seat and the pitch variable plate, and the slider and the guide rail are slidably engaged to make the pitch variable plate slidably connected to the fixed seat.

[0031] Optionally, the focusing ring lifting structure includes:

[0032] an ejector pin component, the ejector pin component comprising an ejection seat and a plurality of ejector pins disposed on the ejection seat and corresponding to the respective ring bodies of the focus ring, wherein the gaps between the ejector pins and the corresponding ring bodies increase in equal steps according to the arrangement order of the corresponding ring bodies from top to bottom within the focus ring;

[0033] A driving device is connected to the lifting seat through a transmission rod to drive the lifting seat to reciprocate along the axial direction of the focusing ring.

[0034] Optionally, the transmission rod includes a rod body, a fixed flange and a bellows, the fixed flange is used to be sealed and fixedly connected to the etching machine, the rod body passes through the fixed flange and is transmission-connected to the ejector component, and the two ends of the bellows are respectively sealed and connected to the fixed flange and the base of the rod body.

[0035] Optionally, the ejector pins are arranged at intervals along the circumferential direction around the axis of the focusing ring.

[0036] Optionally, the driving device is a piston cylinder; or, the driving device is a linear motor; or, the driving device includes a rotary motor and a transmission structure.

[0037] Optionally, the focusing ring lifting structure further includes a positioning sleeve shaft, which is used to be fixedly connected to the etching machine and is used to guide and position the ejector pin.

[0038] An etching machine comprises the focus ring as described in any one of the above items and the focus ring lifting structure as described in any one of the above items.

[0039] A plasma etching device comprises the etching machine as described above.

[0040] It can be seen from the above technical solution that the present invention discloses a focusing ring, which includes a plurality of stacked ring bodies, each of which is independently arranged, and the axial dimension of the ring body located at the top layer is greater than the maximum lifting height allowed by the focusing ring. The present invention provides a split focusing ring. During use, each ring body can be lifted, so that the large space below the original focusing ring after it is lifted as a whole is divided into several small spaces through each ring body. Each small space is only connected by a small narrow gap between the structures. The concentration and activity of charged particles in the plasma in the small space are limited, thereby achieving the purpose of preventing arc discharge and avoiding the problem of sparks or focus ring fragmentation. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] FIG1 is a schematic diagram of the structure of the focusing ring after being lifted in the prior art;

[0043] FIG2 is a schematic diagram of a partial structure of a focusing ring provided by an embodiment of the present invention;

[0044] FIG3 is a schematic diagram of a partial structure of a focus ring provided by another embodiment of the present invention;

[0045] FIG4 is a schematic diagram of a partial structure of a focus ring provided by yet another embodiment of the present invention;

[0046] FIG5 is a partial cross-sectional view of an etching machine equipped with a focus ring provided in an embodiment of the present invention;

[0047] FIG6 is a partial cross-sectional view of an etching tool equipped with a focus ring provided by an embodiment of the present invention before the focus ring is consumed and lifted up;

[0048] FIG7 is a partial cross-sectional view of an etching machine equipped with a focus ring provided by an embodiment of the present invention after the focus ring is consumed and lifted up;

[0049] FIG8 is a cross-sectional view of a focus ring lifting structure provided by an embodiment of the present invention, taken along a plane passing through the axis of the focus ring;

[0050] FIG9 is a cross-sectional view of a focus ring lifting structure provided by an embodiment of the present invention, taken along a cross-section perpendicular to the radial direction of the focus ring;

[0051] FIG10 is a top view of a focus ring lifting structure provided by an embodiment of the present invention;

[0052] FIG11 is a partial cross-sectional view of a focus ring lifting structure at a variable pitch transmission mechanism according to an embodiment of the present invention;

[0053] FIG12 is a schematic structural diagram of a focus ring lifting structure provided by an embodiment of the present invention with a pitch-variable plate of a pitch-variable transmission mechanism in an initial state;

[0054] FIG13 is a schematic structural diagram of a focus ring lifting structure provided by an embodiment of the present invention during movement of a pitch-variable plate of a pitch-variable transmission mechanism;

[0055] FIG14 is a cross-sectional view of a focus ring lifting structure provided by another embodiment of the present invention, taken along a plane passing through the axis of the focus ring;

[0056] FIG15 is a cross-sectional view of a focus ring lifting structure provided by another embodiment of the present invention, taken along a section perpendicular to the radial direction of the focus ring;

[0057] 16 to 20 are partial enlarged schematic diagrams of point A in FIG15 at various stages of the lifting process of the focus ring lifting structure provided by another embodiment of the present invention.

[0058] In the figure: 10 is a focus ring; 1 to 5 are ring bodies; 20 is a focus ring lifting structure with evenly distributed lifting; 21, 211, 212, 213, and 214 are ejectors; 22 is a positioning sleeve shaft; 23 is a transmission rod; 231 is a fixed flange; 232 is a bellows; 233 is a rod body; 24 is a positioning sleeve; 241 is a guide hole; 25 is a follower shaft; 26 is a pitch-variable plate; 261, 262, 263, and 264 are pitch-variable notches; 27 is a guide sliding mechanism; 271 is a guide rail; 272 is a slider; 28 is a fixed seat; 29 is a push-rod type stepping motor; 20' is a focusing ring lifting structure for orderly lifting; 21', 211', 212', 213', and 214' are ejectors; 22' is a positioning sleeve; 23' is a lifting seat; 24' is a transmission rod; 241' is a fixed flange; 242' is a bellows; 243' is a rod body; 25' is a stop pin; 26' is a motor mounting seat; 27' is a push-rod type stepper motor; 28' is a motor cover; 30 is a wafer; 40 is an electrostatic chuck; 50 is an intermediate ring; 60 is an edge ring; 70 is an insulating ring; and 80 is a base. DETAILED DESCRIPTION

[0059] One of the core aspects of the present invention is to provide a focusing ring whose structural design enables it to avoid arc discharge caused by excessive space at the bottom of the focusing ring after it is lifted, thereby avoiding the problem of sparks or focus ring breakage.

[0060] Another core of the present invention is to provide a focusing ring lifting structure matched with the above-mentioned focusing ring, as well as a plasma etching device and an etching machine equipped with the above-mentioned focusing ring and its lifting structure.

[0061] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0062] Please refer to FIG. 2 , which is a schematic diagram of a partial structure of a focus ring provided in an embodiment of the present invention.

[0063] A focusing ring 10 is disclosed in an embodiment of the present invention. The focusing ring 10 includes a plurality of stacked ring bodies, that is, the ring bodies of the focusing ring 10 are stacked together in an up-and-down arrangement, and the axial dimensions of the ring bodies may be the same or different. The ring bodies are independently arranged, so that when the ring bodies of the focusing ring 10 are lifted, an isolated small space may be formed under each ring body, that is, the space generated by the lifting of the focusing ring 10 is divided into a plurality of small spaces by the ring bodies of the focusing ring 10, and each small space is connected only by a small narrow gap between the structures. The concentration and activity of the charged particles in the plasma in the small space are limited, thereby achieving the purpose of preventing arc discharge. It should be noted that the focusing ring 10 only allows the top layer to be etched, so the axial dimension of the ring body located at the top layer is greater than the maximum lifting height allowed by the focusing ring 10.

[0064] The focusing ring 10 provided in the embodiment of the present invention adopts a split structure. During use, each ring body of the focusing ring 10 can be lifted. As shown in Figures 5 to 7, the focusing ring 10 includes 5 layers of ring bodies, namely ring body 1, ring body 2, ring body 3, ring body 4 and ring body 5 from top to bottom. The focusing ring 10 includes 5 layers of ring bodies, which is only a specific embodiment proposed in the embodiment of the present invention for the convenience of explanation. In actual situations, it is not limited to 5 layers of ring bodies. The number of ring bodies of the focusing ring 10 can also be other positive integers such as 2, 3, 4, 6, 7... The focusing ring 10 is arranged in the space surrounded by the wafer 30, the electrostatic chuck 40, the intermediate ring 50 and the edge ring 60. The upper surface of the uppermost ring body 1 of the focusing ring 10 is higher than the upper surface of the wafer 30, which serves to change the distribution and morphology of the plasma sheath in the edge area of ​​the wafer 30.

[0065] The bottom ring body 5 of the focus ring 10 can be supported by both the electrostatic chuck 40 and the edge ring 60, or by the focus ring lifting structure 20. As shown in Figure 5, a narrow gap exists between side A (inner surface) of the focus ring 10 and the intermediate ring 50, and between side B (outer surface) of the focus ring 10 and the edge ring 60. This ensures that both sides A and B of the focus ring 10 are not subject to friction during the lifting process, reducing the risk of particle generation. In some configurations, the intermediate ring 50 can be omitted and replaced by the ceramic outer ring of the electrostatic chuck 40.

[0066] After a certain radio frequency time (RFH), the topmost ring body 1 of the focus ring 10 is etched. As shown in Figure 6, the etched amount S is larger on the inside and smaller on the outside, with the maximum etch height H occurring on the inside. When the etched amount S reaches a preset threshold, the focus ring lifting structure 20 raises the focus ring 10 to the maximum etch height H, where H = H1 + H2 + H3 + H4 + H5, to maintain process stability, as shown in Figure 7.

[0067] In summary, compared with the prior art, the focusing ring 10 provided in the embodiment of the present invention adopts a split structure, and can divide the large space below the original focusing ring 10 after it is lifted up as a whole into several small spaces through each ring body. Each small space is only connected by a small narrow gap between the structures. The concentration and activity of the charged particles in the plasma in the small space are limited, thereby achieving the purpose of preventing arc discharge and avoiding the generation of sparks or the problem of the focus ring 10 being broken.

[0068] As shown in Figure 2, the axial size (thickness) of the ring body 1 located at the top layer is larger than the axial size (thickness) of the remaining ring bodies 2, 3, 4, and 5 to withstand the etching during the production process. The axial sizes of the remaining ring bodies are smaller than the axial size of the ring body located at the top layer, and are only used to divide the lower space after the ring body located at the top layer is lifted. Of course, the axial sizes of the remaining ring bodies except the ring body located at the top layer may be the same or different. In an embodiment of the present invention, the axial sizes of the remaining ring bodies except the ring body located at the top layer are the same to facilitate the subsequent control of the focusing ring lifting structure 20.

[0069] Preferably, the mating surface between the two adjacent ring bodies is an annular plane, a conical surface or a concave-convex surface. The annular plane can be perpendicular to the axis of the ring body or not perpendicular to the axis of the ring body. The tapering direction and cone angle of the conical surfaces between the ring bodies can be the same or different. As shown in Figure 2, in a specific embodiment of the present invention, the mating surface between the two adjacent ring bodies is an annular plane and is perpendicular to the axis of the ring body. The structural design of this planar focusing ring 10 is simple, easy to process, and can be used in most working conditions.

[0070] Of course, in other embodiments, the mating surface between the two adjacent ring bodies may also be a curved surface; or, the mating surface between the two adjacent ring bodies may be a zigzag surface; or, the mating surface between the two adjacent ring bodies may be a combination of at least two of the three: a plane, a curved surface, and a zigzag surface.

[0071] Specifically, as shown in Figure 3, in another embodiment provided by the embodiment of the present invention, one of the mating surfaces between the two adjacent ring bodies includes a first annular boss and a first annular groove alternately arranged along the radial direction of the ring body, and the other mating surface between the two adjacent ring bodies includes a second annular boss and a second annular groove alternately arranged along the radial direction of the ring body, the first annular boss is embedded in the second annular groove, and the second annular boss is embedded in the first annular groove.

[0072] As shown in Figure 4, in another embodiment provided by the embodiment of the present invention, the mating surface between the two adjacent ring bodies includes a plurality of annular abutment surfaces arranged in a ring-like manner along the radial direction of the ring body, and each annular abutment surface is arranged in sequence and spaced apart in a step-like manner along the axial direction of the ring body.

[0073] It should be noted that the above-mentioned plane, conical surface or concave-convex surface structure can be mixed with the matching surface shown in Figure 3 or Figure 4, as long as it can be ensured that two adjacent ring bodies can be stacked on each other.

[0074] The two mating surface solutions shown in Figures 3 and 4 can further divide the small space between the two ring layers into multiple smaller spaces, which is more effective in preventing arc discharge. However, due to the limitations of part design thickness and material brittleness, they are generally only used in conditions with a small number of layers.

[0075] Preferably, in an embodiment of the present invention, the materials of the various ring bodies of the focusing ring 10 may be the same or different, the ring body located on the top layer is made of one of SiO2, Si, SiC and Y2O3, and the remaining ring bodies are made of SiO2 or Al2O3.

[0076] An embodiment of the present invention further provides a focus ring lifting structure for lifting the focus ring 10 as described in the above embodiment. The focus ring lifting structure includes a driving unit and multiple executing units. The driving unit is connected to the executing units in a transmission manner. The executing units are arranged in a one-to-one correspondence with the ring bodies of the focus ring 10. Each executing unit can have multiple executing ends, and the executing ends are arranged at intervals along the circumference of the corresponding ring body of the focus ring 10. It is best to arrange them uniformly along the circumference of the corresponding ring body of the focus ring 10, or a focus ring 10 can be configured with multiple focus ring lifting structures arranged at intervals along the circumference of the focus ring 10, and the corresponding executing units of each focus ring lifting structure operate synchronously. The driving unit of the focus ring lifting structure is used to drive each executing unit to lift each ring body of the focus ring 10 to a preset height according to preset instructions.

[0077] Specifically, in the embodiments shown in FIG. 8 to FIG. 11 , a focus ring lifting structure 20 with evenly distributed lifting is provided. The focus ring lifting structure 20 with evenly distributed lifting includes a pin component, a variable pitch transmission mechanism, a positioning component, and a driving device.

[0078] Among them, the ejector component includes a plurality of ejector pins 21 that are transmission-connected to the respective ring bodies of the focus ring 10. The number of the ejector pins 21 is a positive integer multiple of the number of the ring bodies of the focus ring 10. For example, the number of the ejector pins 21 can be the same as the number of the ring bodies of the focus ring 10, or the number of the ejector pins 21 can be 2 times, 3 times... the number of the ring bodies of the focus ring 10. The ejector pins serve as the executors of the focus ring lifting structure 20 for evenly dividing the lifting. The upper end surfaces of the ejector pins 21 are used to contact and cooperate with the bottom surfaces of the ring bodies corresponding to the focus ring 10. To ensure that the lifting forces on the respective ring bodies are consistent, in an embodiment of the present invention, the ejector pins 21 are arranged circumferentially around the axis of the focus ring 10 at intervals.

[0079] As shown in Figures 8 and 9, the evenly distributed focus ring lifting structure 20 is mounted on the base 80 of the etching tool. It passes through the insulating ring 70, the intermediate ring 50, and the edge ring 60 from bottom to top. Finally, only tiny pins 21 contact the various rings of the focus ring 10, driving each ring of the focus ring 10 to achieve an evenly distributed upward lifting action. The base 80 serves as a partition between the vacuum environment and the atmospheric environment. The portion of the evenly distributed focus ring lifting structure 20 below the base 80 is in the atmospheric environment, while the portion above the base 80 is in the vacuum environment.

[0080] Preferably, in order to ensure the movement stability of the ejector pin 21, as shown in Figure 9, in this embodiment, a positioning sleeve shaft 22 is further provided on the insulating ring 70 and / or the edge ring 60, and the ejector pin 21 passes through the positioning sleeve shaft 22. The positioning sleeve shaft 22 constrains and guides the ejector pin 21 to ensure that the ejector pin 21 slides back and forth along a preset direction.

[0081] The pitch-variable transmission mechanism includes a pitch-variable plate 26 and a transmission rod 23. A transmission structure is provided on the pitch-variable plate 26, which corresponds to and cooperates with each transmission rod 23. The transmission rod 23 is transmission-connected to the ejector pin 21, and the end of the transmission rod 23 away from the ejector pin 21 contacts and cooperates with the transmission structure. The transmission ratio of each transmission structure decreases proportionally according to the arrangement order of the corresponding ring bodies from top to bottom in the focus ring 10. That is, when the pitch-variable plate 26 moves along the axial direction perpendicular to the focus ring 10, the movement distance of each ejector pin 21 decreases proportionally according to the arrangement order of the corresponding ring bodies from top to bottom in the focus ring 10. The transmission ratio of the transmission structure connected to the ejector pin corresponding to the uppermost ring body is the highest, and the transmission ratio of the transmission structure connected to the ejector pin corresponding to the lower ring body decreases from top to bottom. That is, as the pitch-variable plate 26 moves, each ejector pin 21 also moves accordingly, but the movement distance of each ejector pin 21 is different.

[0082] The above-mentioned moving direction of the pitch variable plate 26 is described based on the rectangular pitch variable plate 26 shown in Figures 8 to 11. The actual moving direction of the pitch variable plate 26 is not limited to reciprocating movement perpendicular to the axial direction of the focus ring 10. For example, the pitch variable plate 26 can be an arc-shaped plate or an annular plate, and the driving of the ejector pins 21 is achieved by driving the pitch variable plate 26 to rotate around the axial direction of the focus ring 10. In this case, the pitch variable plate 26 can be provided with multiple groups of transmission structures to simultaneously drive multiple groups of ejector pins 21 through the transmission rod 23. Each group of transmission structures can drive the same number of ejector pins 21 as the ring body of the focus ring 10 and in a one-to-one correspondence. That is, the structural design of the pitch variable plate 26 can be used to simultaneously drive multiple groups of ejector pins.

[0083] In the above embodiment, the transmission rod 23 includes a rod body 233, a fixed flange 231 and a bellows 232. The fixed flange 231 is used to be sealed and fixedly connected to the base 80 of the etching machine. A sealing ring groove is provided on the flange surface where the fixed flange 231 and the base 80 cooperate. A sealing ring is provided in the sealing ring groove to achieve static sealing between the fixed flange 231 and the base 80. The rod body 233 passes through the fixed flange 231 and is transmission-connected to the ejector component. The two ends of the bellows 232 are respectively sealed with the fixed flange 231 and the base of the rod body 233. The bellows 232 is used to achieve dynamic sealing between the fixed flange 231 and the rod body 233. When in action, the bellows 232 is pushed to compress to maintain stable vertical movement, which also meets the requirement that the part above the base 80 is in a vacuum environment.

[0084] The positioning member is used to guide and position each ejector pin 21 and / or transmission rod 23 so that each ejector pin can reciprocate along the axial direction of the focusing ring 10. Because each ejector pin 21 needs to move a different distance, the moving direction of the pitch plate 26 is different from the moving direction of the ejector pin 21. In order to ensure that the ejector pin 21 or the transmission rod 23 moves in a preset direction, a positioning member is required to guide the ejector pin 21 and / or the transmission rod 23.

[0085] The drive device is used to drive the pitch plate 26 to move back and forth in a preset direction. The movement path of the pitch plate 26 can be straight or curved. The drive device is a piston cylinder, or the drive device is a linear motor, or the drive device includes a rotary motor and a transmission mechanism, and the transmission mechanism is used to convert the rotation of the rotary motor into reciprocating movement. The piston cylinder can be a pneumatic cylinder or a hydraulic cylinder, and the transmission mechanism can be a screw slider mechanism, a gear rack mechanism, a cam connecting rod mechanism, etc. In a specific embodiment of the present invention, the drive device uses a push rod type stepper motor 29. The push rod type stepper motor 29 integrates a stepper motor and a high-precision screw structure, directly converting the rotational motion of the stepper motor into high-precision linear motion, and has a compact structure. The output shaft of the push rod type stepper motor 29 is fixed to the pitch plate 26, pushing the pitch plate 26 to achieve controllable, high-precision, horizontal movement.

[0086] Preferably, in an embodiment of the present invention, as shown in FIG11 , the transmission structure is a pitch-varying slot 261 to 264, a follower shaft 25 is provided at the bottom of the transmission rod 23, the axis of the follower shaft 25 intersects with the axis of the transmission rod 23, the follower shaft 25 and the pitch-varying slot 261 to 264 are slidably matched, the follower shaft 25 is connected to the base of the rod body 233 of the transmission rod 23, and the angle between the connecting line between the two ends of the pitch-varying slot 261 to 264 and the horizontal plane is equal to the angle of the corresponding ring body in the order of arrangement from top to bottom in the focusing ring 10. The ratio is reduced. As can be seen from Figure 11, for the focusing ring 10 with four-layer ring bodies, the pitch plate is provided with four pitch slots 261~264, and the four pitch slots 261~264 are arranged in sequence from right to left. The leftmost pitch slot 264 is transmission-connected to the uppermost ring body of the focusing ring 10, and the angle between the line connecting the two ends of the leftmost pitch slot 264 and the horizontal plane is also the largest among the four pitch slots 261~264. The angles between the lines connecting the two ends of the remaining pitch slots 263, 262, and 261 and the horizontal plane decrease in sequence.

[0087] The "equal distribution" of the focus ring lifting structure 20 for equal lift in the embodiment of the present invention is achieved by utilizing the center curve function of the pitch-variable slots 261-264 of the pitch-variable plate 26, as shown in Figure 11. A motor drives the pitch-variable plate 26 to move in the X-direction in the figure, while the follower shaft 25, embedded within the pitch-variable slots 261-264, is constrained to move only in the Z-direction in the figure. The relationship between the two movements is controlled by the center curve function of the pitch-variable slots 261-264. By setting the center curve function to be proportional, the "equal distribution" of the focus ring lifting structure 20 for equal lift is achieved, ensuring that the gaps below each ring remain the same during the lifting process.

[0088] Through the design of the above-described pitch-changing slots 261-264, when the drive device drives the pitch-changing plate 26 to move left or right, the pitch-changing slots 261-264, because they are inclined and have a proportional central curve function, can, through sliding engagement with the follower shaft 25, convert the left and right movement of the pitch-changing plate 26 into the up and down reciprocating movement of the ejector pin 21 and the transmission rod 23. Specifically, when the drive device drives the pitch-changing plate 26 to the right, the ejector pin 21 and the transmission rod 23 move upward; when the drive device drives the pitch-changing plate 26 to the left, the ejector pin 21 and the transmission rod 23 move downward. Furthermore, because the angles between the pitch-changing slots 261-264 and the horizontal plane decrease proportionally from left to right, the distances traveled by the ring bodies 1-4 of the focus ring 10 also decrease from top to bottom during the movement of the pitch-changing plate 26, ensuring that a gap is created below each ring body and that each gap is always equal.

[0089] The above-mentioned up, down, left, right, X, and Z are only for the convenience of explaining the movement directions of the pitch change plate 26, the ejector pin 21, and the transmission rod 23, and are only for the directions in Figure 11. In actual application, the movement directions of the pitch change plate 26, the ejector pin 21, and the transmission rod 23 are determined according to the actual layout.

[0090] In the above embodiment, when the transmission structure is a pitch-varying slot 261~264, the above-mentioned positioning component includes a positioning sleeve 24, a guide hole 241 is provided in the positioning sleeve 24, and a guide groove connected to the guide hole 241 is provided on the side wall corresponding to the positioning sleeve 24 and the guide hole 241, and the transmission rod 23 slides with the guide hole 241. In the embodiment of the present invention, the base of the rod body 233 of the transmission rod 23 slides with the guide hole 241, and the transmission rod 23 moves back and forth up and down under the guiding limit action of the guide hole 241. The length direction of the guide groove is parallel to the axial direction of the guide hole 241, and the follower shaft 25 extends from the guide groove and contacts and cooperates with the pitch-varying slots 261~264.

[0091] It should be noted that the transmission structure is not limited to the above embodiment. In another embodiment, the above transmission structure can also be a variable pitch inclined plane, and the angle between the variable pitch inclined plane and the horizontal plane decreases proportionally according to the arrangement order of the corresponding ring bodies from top to bottom in the focusing ring 10.

[0092] Preferably, as shown in Figures 10 and 11, the equally-lifted focusing ring lifting structure also includes a fixed seat 28, and the pitch variable plate 26 can be reciprocated on the fixed seat 28 along the axial direction perpendicular to the focusing ring 10. The fixed seat 28 provides an installation position and support for the pitch variable plate 26 to ensure the stability of the movement of the pitch variable plate 26.

[0093] Specifically, as shown in Figure 11, in an embodiment of the present invention, the above-mentioned fixed seat 28 and the pitch change plate 26 are coordinated through a guide sliding mechanism 27. The guide sliding mechanism 27 includes a slider 272 provided on one of the fixed seat 28 and the pitch change plate 26 and a guide rail 271 provided on the other of the fixed seat 28 and the pitch change plate 26. The slider 272 and the guide rail 271 are slidably coordinated to enable the pitch change plate 26 to be slidably connected to the fixed seat 28. The guide rail 271 and the slider 272 cooperate to constrain the slider, thereby ensuring that the pitch change plate 26 can move relative to the fixed seat 28 along a preset direction (left and right direction in Figure 11).

[0094] Specifically, in the embodiments shown in FIGS. 8 and 9, the focusing ring 10 is composed of four parts: ring body 1, ring body 2, ring body 3, and ring body 4. Correspondingly, 4 thimbles are also designed: thimble 211, thimble 212, thimble 213, and thimble 214. The above 4 ring bodies correspond to the 4 thimbles one by one and are in contact with each other. The bottoms of the above four thimbles are respectively connected to the transmission rods 23. The transmission rods 23 are respectively controlled by the variable pitch slots 261, variable pitch slots 262, variable pitch slots 263, and variable pitch slots 264 through the follower shafts 25, as shown in FIG. 11. The central curve function of the 4 variable pitch slots adopts the simplest linear function Z = n×X.

[0095] As shown in FIGS. 11 and 12, in the initial state, the follower shafts 25 are on a horizontal line and are evenly distributed between them. The distance between two adjacent follower shafts 25 is S. At the variable pitch slot 261 (the rightmost variable pitch slot), the central curve function is defined as: Z = X, where α1 = 45°, which corresponds to the ring body 4 at the bottom layer of the focusing ring 10. At the variable pitch slot 262, the central curve function is defined as: Z = 2×X, where α2 = 26.565°, which corresponds to the ring body 3 of the focusing ring 10. At the variable pitch slot 263, the central curve function is defined as: Z = 3×X, where α3 = 18.435°, which corresponds to the ring body 2 of the focusing ring 10. At the variable pitch slot 264, the central curve function is defined as: Z = 4×X, where α4 = 14.036°, which corresponds to the ring body 1 at the top layer of the focusing ring 10.

[0096] As shown in FIG. 13, in the moving state, the variable pitch plate 26 moves an arbitrary distance H in the X direction, 0 < H ≤ H total, where H total is the maximum moving distance of the variable pitch plate 26 in the X direction. At this time, the follower shafts 25 at the variable pitch slots 261 to 264 move heights of H, 2H, 3H, and 4H from right to left in sequence. The respective ring bodies of the corresponding focusing ring 10 rise by H, 2H, 3H, and 4H from bottom to top in sequence. The height of the small space divided by each two ring bodies and the bottom of the bottom layer ring body is H, effectively achieving the purpose of evenly dividing and lifting.

[0097] In another embodiment, as shown in the embodiments of FIGS. 14 and 15, a focusing ring lifting structure 20' for sequential lifting is provided. Different from the above-mentioned focusing ring lifting structure 20 for evenly dividing and lifting, the driving method of the focusing ring lifting structure 20' for sequential lifting is not to make each ring body act simultaneously, but to make each ring body start to move in sequence one by one.

[0098] As shown in Figures 14 to 16, the above-mentioned orderly lifting focus ring lifting structure 20' includes a pin component and a driving device, wherein the pin component includes a lifting seat 23' and a plurality of pins 21' arranged on the lifting seat 23' and corresponding to each ring body of the focus ring 10. The number of the pins 21' can be the same as the number of ring bodies of the focus ring 10, or can be a positive integer multiple of the number of ring bodies of the focus ring 10. The gaps between the pins 21' and the corresponding ring bodies increase arithmetic progression according to the arrangement order of the corresponding ring bodies from top to bottom in the focus ring 10. The pins 21' serve as the executors of the orderly lifting focus ring lifting structure 20', that is, the pins 211' corresponding to the uppermost ring body 1 can contact the uppermost ring body 1, or the pins 211' corresponding to the uppermost ring body 1 can not contact the uppermost ring body 1, and the pins corresponding to the remaining ring bodies do not contact the corresponding ring bodies, and the gaps between the pins and the ring bodies increase arithmetic progression according to the order of the ring bodies from top to bottom.

[0099] As shown in Figures 14 and 15 , in this embodiment, the orderly-lifting focus ring lifting structure 20' is mounted on the base 80 of the etching tool. It passes from bottom to top through the insulating ring 70, the intermediate ring 50, and the edge ring 60. Finally, through the ejector pins 21', it contacts the various rings of the focus ring 10, driving the various rings of the focus ring 10 to achieve an orderly upward lifting action. The base 80 is a partition between the vacuum environment and the atmospheric environment. The portion of the orderly-lifting focus ring lifting structure 20' below the base 80 is in the atmospheric environment, while the portion above the base 80 is in the vacuum environment.

[0100] Preferably, in order to ensure the movement stability of the ejector pin 21', as shown in Figures 14 and 15, in this embodiment, a positioning sleeve shaft 22' is further provided on the insulating ring 70 and / or the edge ring 60, and the ejector pin 21' passes through the positioning sleeve shaft 22'. The positioning sleeve shaft 22' constrains and guides the ejector pin 21' to ensure that the ejector pin 21' slides back and forth along a preset direction.

[0101] The driving device is connected to the lifting seat 23' through the transmission rod 24' to drive the lifting seat 23' to move back and forth along the axial direction of the focusing ring 10. The driving device can be a piston cylinder, or the driving device can be a linear motor, or the driving device can include a rotary motor and a transmission mechanism, and the transmission mechanism is used to convert the rotation of the rotary motor into reciprocating movement. The above-mentioned piston cylinder can be a pneumatic cylinder or a hydraulic cylinder, and the transmission mechanism can be a screw slider mechanism, a gear rack mechanism, a cam connecting rod mechanism, etc.

[0102] In this embodiment of the present invention, the drive device utilizes a push-rod stepper motor 27'. This compact, integrated stepper motor and high-precision lead screw directly converts the stepper motor's rotational motion into high-precision linear motion. The output shaft of the push-rod stepper motor 27' is fixed to the lifting base 23', pushing the base 23' to achieve controlled, high-precision, vertical movement.

[0103] The above-mentioned push rod type stepper motor 27' is fixedly mounted on the base 80 by the motor mounting base 26' and is wrapped by the motor cover 28' mounted on the base 80. The motor cover 28' and the base 80 are sealed to form a relatively closed and stable working space, isolating the air and forming a vacuum environment, thereby placing the push rod type stepper motor 27' in a vacuum environment, preventing the push rod type stepper motor 27' from being affected by dust and impurities, ensuring the normal operation of the push rod type stepper motor 27', extending the service life of the push rod type stepper motor 27', reducing the number of maintenance times, and improving the reliability of the etching machine.

[0104] Under certain operating conditions, a partial vacuum environment exists at the bottom of the base 80. To facilitate the design of the motor's fixed position, a motor cover 28' is added to isolate the atmospheric environment, creating a partial vacuum environment to accommodate the push-rod type stepper motor 27'. Of course, the motor cover 28' is not required and can be omitted under certain operating conditions.

[0105] The driving device is connected to the lifting seat 23' through a transmission rod 24', and the transmission rod 24' includes a rod body 243', a fixed flange 241' and a bellows 242'. The fixed flange 241' is used to be sealed and fixedly connected to the base 80 of the etching machine. A sealing ring groove is provided on the flange surface where the fixed flange 241' and the base 80 match. A sealing ring is provided in the sealing ring groove to achieve a static seal between the fixed flange 241' and the base 80. The rod body 243' passes through the fixed flange 241' and is transmission-connected to the lifting seat 23'. The two ends of the bellows 242' are respectively connected to the fixed flange 241' and the rod body 24 3' is sealed and connected to the base, and the bellows 242' is used to achieve dynamic sealing between the fixed flange 241' and the rod body 243'. When in action, the bellows 242' is pushed to be compressed to maintain stable vertical movement, and also meet the requirement that the part above the base 80 is in a vacuum environment. The base of the rod body 243' slides with the inner wall of the above-mentioned motor mounting seat 26' to achieve constraint and guidance of the transmission rod 24', and the side wall of the motor mounting seat 26' is provided with a limiting slide groove, and the base of the rod body 243' is provided with a stop pin 25', and the stop pin 25' cooperates with the limiting slide groove to prevent the transmission rod 24' from rotating.

[0106] The "orderly" in the above-mentioned orderly lifting focus ring lifting structure 20' refers to the gradual transition of the division of the lifting space from large at the top and small at the bottom to the same top and bottom and finally stability. During the lifting process, the various ring bodies of the focus ring 10 are lifted from top to bottom in sequence until all the ring bodies are lifted to the set position. At this time, the height of the topmost ring body is the total lifting height Htotal. The condition for the lifting of the next layer of focus ring 10 is: the height of the small space divided above the focus ring 10 reaches the designed maximum height Hmax. For a structure with N layers of focus rings 10, Hmax = Htotal / N. Moreover, after any layer of focus ring 10 is lifted, it and all the focus rings 10 above it will move together, and the height of the small space that has been formed will no longer change and will always be Hmax.

[0107] The process of orderly lifting is described below with reference to specific embodiments.

[0108] As shown in FIG16 , in the illustrated embodiment, the focus ring 10 is in an unlifted state. The focus ring 10 is composed of four parts, namely, the ring body 1, the ring body 2, the ring body 3, and the ring body 4, which are stacked in sequence from top to bottom. Therefore, four ejector pins 211 ′, 212 ′, 213 ′, and 214 ′ are provided accordingly. The top of each ejector pin has a different height, from high to low, namely, the ejector pin 211 ′ corresponding to the ring body 1, the ejector pin 212 ′ corresponding to the ring body 2, the ejector pin 213 ′ corresponding to the ring body 3, and the ejector pin 214 ′ corresponding to the ring body 4.

[0109] As shown in Figure 16, in the free state, the clearances between the four rings and the four ejector pins are designed to be J1, J2, J3, and J4, respectively, where J1 < J2 < J3 < J4. Defining the maximum height of the small space formed by the segmentation as Hmax, then J1 ≥ 0, J2 = J1 + Hmax, J3 = J2 + Hmax, and J4 = J3 + Hmax. J1, J2, J3, and J4 increase in an arithmetic progression, achieving "orderly" jacking.

[0110] At the same time, for ease of understanding, the heights of the small spaces formed by the divisions are defined from top to bottom as H1, H2, H3, and H4. As shown in Figure 16, in the initial state, when the focus ring 10 is not lifted, H1 = H2 = H3 = H4 = 0. As shown in Figure 20, in the final state, when each ring body of the focus ring 10 is lifted to the preset position, H14 = H24 = H34 = H44 = Hmax. After reaching the final state, the orderly lifting focus ring lifting structure will no longer be allowed to move.

[0111] As shown in Figure 17, at the moment shown in the figure, the total lifting height Htotal1 satisfies Htotal1≤Hmax. At this time, only the ring body 1 is lifted. At this time, the lifted height of the ring body 1 is H11=Htotal1, H21=H31=H41=0, and the gap J11 between the ejector pin 211' and the ring body 1 is 0. At the same time, the ejector pins 212', 213' and 214' also move upward synchronously. The gap J21 between the ejector pin 212' and the ring body 2 is J21=(Hmax-Htotal1)≥0, the gap between the ejector pin 213' and the ring body 3 is J31=J21+Hmax, and the gap between the ejector pin 214' and the ring body 4 is J41=J31+Hmax.

[0112] As shown in Figure 18, at the moment shown in the figure, the total lifting height Htotal2 satisfies Hmax<Htotal2≤2×Hmax. At this time, only the ring body 1 and the ring body 2 are lifted, that is, the gap H12 between the ring body 1 and the ring body 2 satisfies H12=Hmax. In the subsequent lifting process, the gap H12 between the ring body 1 and the ring body 2 no longer changes, the gap H22 between the ring body 2 and the ring body 3 satisfies H22=Htotal2-Hmax, the gap H32 between the ring body 3 and the ring body 4 and the gap H42 below the ring body 4 satisfy H32=H42=0, the gap J12 between the ejector pin 211' and the ring body 1 and the gap J22 between the ejector pin 212' and the ring body 2 satisfy J12=J22=0, the gap J32 between the ejector pin 213' and the ring body 3 satisfies J32=(2×Hmax-Htotal2)≥0, and the gap J42 between the ejector pin 214' and the ring body 4 satisfies J42=J32+Hmax.

[0113] As shown in Figure 19, at the moment shown in the figure, when the total lifting height Htotal3 satisfies 2×Hmax<Htotal3≤3×Hmax, only the ring body 1, the ring body 2 and the ring body 3 are lifted. At this time, the gap H13 between the ring body 1 and the ring body 2 and the gap H23 between the ring body 2 and the ring body 3 satisfy H13=H23=Hmax, and in the subsequent lifting process, the gap H13 between the ring body 1 and the ring body 2 and the gap H23 between the ring body 2 and the ring body 3 no longer change, and the gap H33 between the ring body 3 and the ring body 4 satisfies H33=Htotal3-2×Hm ax, the ring body 4 is not lifted up, so the gap H43 below the ring body 4 satisfies H43=0. At this time, the ejector pin 211' contacts the ring body 1, the ejector pin 212' contacts the ring body 2, and the ejector pin 213' contacts the ring body 3. That is, the gap J13 between the ejector pin 211' and the ring body 1, the gap J23 between the ejector pin 212' and the ring body 2, and the gap J33 between the ejector pin 213' and the ring body 3 satisfy J13=J23=J33=0, and the gap J43 between the ejector pin 214' and the ring body 4 satisfies J43=(3×Hmax-Htotal3)≥0.

[0114] As shown in Figure 20, at the moment shown in the figure, when the total lifting height Htotal4 satisfies 3×Hmax<Htotal4≤4×Hmax, the ring bodies 1, 2, 3 and 4 are all lifted up. At this time, the gap H14 between the ring bodies 1 and 2, the gap H24 between the ring bodies 2 and 3, and the gap H34 between the ring bodies 3 and 4 satisfy H14=H24=H34=Hmax, and the gap H44 below the ring body 4 satisfies H44=Htotal4-3×Hmax, and each ejector pin is in contact with each ring body, that is, the gap J14 between the ejector pin 211' and the ring body 1, the gap J24 between the ejector pin 212' and the ring body 2, the gap J34 between the ejector pin 213' and the ring body 3, and the gap J44 between the ejector pin 214' and the ring body 4 satisfy J14=J24=J34=J44=0.

[0115] Preferably, in the above embodiment of the present invention, in order to ensure that the lifting force on each ring body is consistent, the ejector pins are arranged at intervals along the circumferential direction around the axis of the focusing ring 10 .

[0116] The present invention also provides an etching machine, as shown in Figure 5, the etching machine includes the focus ring 10 as described in the above embodiment and the focus ring lifting structure as described in the above embodiment. The focus ring lifting structure can be an evenly lifted focus ring lifting structure 20 or an orderly lifted focus ring lifting structure 20'. Since the etching machine adopts the focus ring 10 and the focus ring lifting structure in the above embodiment, please refer to the above embodiment for the technical effects of the etching machine.

[0117] As shown in FIG5 , in the above-mentioned etching machine, the focus ring 10 is arranged in the space enclosed by the wafer 30, the electrostatic chuck 40, the intermediate ring 50 and the edge ring 60. The upper surface of the uppermost ring body of the focus ring 10 is higher than the upper surface of the wafer 30, which serves to change the distribution and morphology of the plasma sheath in the edge area of ​​the wafer 30. The lowermost ring body can be supported by the electrostatic chuck 40 and the edge ring 60, or it can be supported by the focus ring lifting structure. There is a gap between the side A of the focus ring 10 and the intermediate ring 50, and a gap between the side B and the edge ring 60, to ensure that there is no friction on both sides A / B of the focus ring 10 during the lifting process, thereby reducing the risk of particle generation. In some structures, the intermediate ring 50 can be omitted and replaced by the ceramic outer ring of the electrostatic chuck 40.

[0118] An embodiment of the present invention further provides a plasma etching device, which includes the etching machine described in the above embodiment. Since the plasma etching device adopts the etching machine in the above embodiment, the technical effects of the plasma etching device please refer to the above embodiment.

[0119] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0120] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A focusing ring, characterized in that: It comprises a plurality of stacked ring bodies, each of which is independently arranged, and the axial dimension of the ring body located at the uppermost layer is greater than the maximum lifting height allowed by the focusing ring.

2. The focusing ring according to claim 1, characterized in that: The axial dimension of the ring body located at the uppermost layer is greater than the axial dimensions of the remaining ring bodies.

3. The focusing ring according to claim 2, characterized in that: The axial dimensions of the remaining ring bodies except the ring body located at the uppermost layer are the same.

4. The focusing ring according to any one of claims 1 to 3, characterized in that: The matching surface between two adjacent ring bodies is an annular plane or a concave-convex surface.

5. The focusing ring according to claim 4, characterized in that: The matching surface between two adjacent ring bodies is an annular plane perpendicular to the axis of the ring body.

6. The focusing ring according to any one of claims 1 to 3, characterized in that: The mating surface between two adjacent ring bodies is a curved surface; or, the mating surface between two adjacent ring bodies is a zigzag surface; or, the mating surface between two adjacent ring bodies is a combination of at least two of a plane, a curved surface and a zigzag surface.

7. The focusing ring according to claim 6, characterized in that: One of the mating surfaces between two adjacent ring bodies includes a first annular boss and a first annular groove alternately arranged along the radial direction of the ring body, and the other mating surface between the two adjacent ring bodies includes a second annular boss and a second annular groove alternately arranged along the radial direction of the ring body, the first annular boss is embedded in the second annular groove, and the second annular boss is embedded in the first annular groove.

8. The focusing ring according to claim 6, characterized in that: The mating surface between two adjacent ring bodies comprises a plurality of annular abutment surfaces which are arranged in a ring-shaped manner along the radial direction of the ring body, and each of the annular abutment surfaces is arranged in a step-like manner in sequence and at intervals along the axial direction of the ring body.

9. The focusing ring according to any one of claims 1 to 3, 5, 7 and 8, characterized in that: The ring body located at the uppermost layer is made of one of SiO2, Si, SiC and Y2O3, and the remaining ring bodies are made of SiO2 or Al2O3.

10. A focusing ring lifting structure, used for lifting the focusing ring as described in any one of claims 1 to 9, characterized in that the focusing ring lifting structure comprises a driving unit and a plurality of executing units, the driving unit is transmission-connected to each of the executing units, each of the executing units is arranged in a one-to-one correspondence with each ring body of the focusing ring, and the driving unit of the focusing ring lifting structure is used for driving each of the executing units to lift each of the ring bodies of the focusing ring to a preset height according to preset instructions.

11. The focus ring lifting structure according to claim 10, characterized in that: The focusing ring lifting structure comprises: An ejector component, the ejector component comprising a plurality of ejectors correspondingly and drivingly connected to the respective ring bodies of the focusing ring; A variable pitch transmission mechanism, the variable pitch transmission mechanism comprising a variable pitch plate and a transmission rod, the variable pitch plate is provided with a transmission structure corresponding to each of the transmission rods, the transmission rod is in transmission connection with the ejector pin, one end of the transmission rod away from the ejector pin is in contact with the transmission structure, and the transmission ratio of each transmission structure is proportionally reduced in sequence according to the arrangement order of the corresponding ring bodies from top to bottom in the focusing ring; A positioning member, the positioning member is used to guide and position each of the ejector pins and / or the transmission rod, so that each of the ejector pins reciprocates along the axial direction of the focusing ring; A driving device is used to drive the pitch-changing plate to move back and forth along a preset direction.

12. The focus ring lifting structure according to claim 11, characterized in that: The transmission structure is a variable pitch slot, a follower shaft is arranged at the bottom of the transmission rod, the axis of the follower shaft intersects with the axis of the transmission rod, the follower shaft and the variable pitch slot are slidably matched, and the angle between the connecting line between the two ends of the variable pitch slot and the horizontal plane is reduced in proportion in sequence according to the arrangement order of the corresponding ring bodies from top to bottom in the focusing ring.

13. The focus ring lifting structure according to claim 12, characterized in that: The positioning component is provided with a guide hole and a guide groove communicated with the guide hole, the transmission rod is slidably matched with the guide hole, and the follower shaft extends from the guide groove and contacts and cooperates with the pitch-changing notch.

14. The focus ring lifting structure according to claim 11, characterized in that: The transmission structure is a pitch-changing inclined plane, and the angle between the pitch-changing inclined plane and the horizontal plane decreases in equal proportion according to the arrangement order of the corresponding ring bodies from top to bottom in the focusing ring.

15. The focus ring lifting structure according to claim 11, characterized in that: The focus ring lifting structure also includes a fixing seat, and the pitch-variable plate is arranged on the fixing seat so as to be reciprocatingly movable along an axial direction perpendicular to the focus ring.

16. The focus ring lifting structure according to claim 15, characterized in that: One of the fixed seat and the pitch-changing plate is provided with a slider, and the other of the fixed seat and the pitch-changing plate is provided with a guide rail. The slider and the guide rail are slidably matched to make the pitch-changing plate slidably connected to the fixed seat.

17. The focus ring lifting structure according to claim 10, characterized in that: The focusing ring lifting structure comprises: An ejector component, the ejector component comprising an ejector seat and a plurality of ejectors disposed on the ejector seat and corresponding to each ring body of the focus ring, wherein the gaps between the ejectors and the corresponding ring bodies are increased in equal steps in accordance with the arrangement order of the corresponding ring bodies from top to bottom in the focus ring; A driving device is connected to the lifting seat through a driving rod to drive the lifting seat to reciprocate along the axial direction of the focusing ring.

18. The focus ring lifting structure according to any one of claims 11 to 17, characterized in that: The transmission rod includes a rod body, a fixed flange and a bellows. The fixed flange is used for sealing and fixed connection with the etching machine. The rod body passes through the fixed flange and is transmission-connected to the ejector component. The two ends of the bellows are respectively sealed and connected to the fixed flange and the base of the rod body.

19. The focus ring lifting structure according to any one of claims 11 to 17, characterized in that: The ejector pins are arranged at intervals in the circumferential direction around the axis of the focusing ring.

20. The focus ring lifting structure according to any one of claims 11 to 17, characterized in that: The driving device is a piston cylinder; or, the driving device is a linear motor; or, the driving device includes a rotary motor and a transmission structure.

21. The focus ring lifting structure according to any one of claims 11 to 17, characterized in that: The focusing ring lifting structure also includes a positioning sleeve shaft, which is used to be fixedly connected to the etching machine, and the positioning sleeve shaft is used to guide and position the ejector pin.

22. An etching machine, characterized in that: It comprises the focusing ring as described in any one of claims 1-9 and the focusing ring lifting structure as described in any one of claims 10-21.

23. A plasma etching device, characterized in that: Comprising the etching machine as described in claim 22.

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