Plasma etching equipment, etching machine table, focusing ring and jacking structure of focusing ring

Abstract

The invention relates to plasma etching equipment, an etching machine table, a focusing ring and a jacking structure thereof, the focusing ring comprises a plurality of stacked ring bodies, the ring bodies are mutually independently arranged, the axial size of the ring body located on the uppermost layer is larger than the maximum jacking height allowed by the focusing ring, and the jacking height of the focusing ring is larger than the maximum jacking height allowed by the focusing ring. According to the split type focusing ring provided by the invention, in the use process, each ring body can be jacked, so that a large space below the whole jacked original focusing ring is divided into a plurality of small spaces through each ring body, and the small spaces are connected only through small slits among structures; and the concentration and activity of charged particles of the plasma in the small space are limited, so that the purposes of preventing the arc discharge phenomenon and avoiding the generation of sparking traces or the fragmentation of the focusing ring are achieved.

Description

Technical Field

[0001] 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

[0002] With the development of semiconductor devices, the chip pattern accuracy is getting higher and higher, and a series of dry etching technologies have been gradually developed. Among them, inductively coupled plasma etching (ICP) is a plasma etching technology for processing micro-nano structures. It has the advantages of fast etching, high selectivity, high anisotropy, small etching damage, high controllability of cross-section profile, and high etched surface flatness. It is currently widely used.

[0003] The etching in the ICP equipment 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.

[0004] When the focus ring is in the plasma filled with etching gas for a long time, the upper surface material will be consumed and the height will decrease. The decrease in the height of the focus ring will bring about a series of changes in etching parameters. The more serious impact is the tilt of the etching path at the edge of the wafer, which reduces the etching uniformity. In the mature existing technology, raising the focus ring to compensate for the amount of etching is an effective method.

[0005] When the focus ring is lifted, a certain amount of space will be created at the bottom, such as Figure 1 As the process continues to develop, the height of the focus ring is constantly increasing, and the bottom space is constantly increasing, which brings a new problem: arc discharge is very easy to occur in the overly large space at the bottom of the focus ring, which instantly generates high heat, causing sparks on the surface at the least, and causing the focus ring to break in severe cases. Summary of the invention

[0006] 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.

[0007] The second object of the present invention is to provide a focusing ring lifting structure matching the above-mentioned focusing ring, as well as a plasma etching device and an etching machine having the above-mentioned focusing ring and its lifting structure.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A focusing ring 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.

[0010] Optionally, the axial dimension of the ring body located at the uppermost layer is greater than the axial dimensions of the remaining ring bodies.

[0011] Optionally, the axial dimensions of the ring bodies except the ring body located at the uppermost layer are the same.

[0012] Optionally, the mating surface between two adjacent ring bodies is an annular plane or a concave-convex surface.

[0013] Optionally, the mating surface between two adjacent ring bodies is an annular plane perpendicular to the axis of the ring body.

[0014] 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.

[0015] 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.

[0016] Optionally, the mating surface between two adjacent ring bodies includes a plurality of annular abutment surfaces arranged in an annular 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.

[0017] Optionally, the ring body located at the uppermost layer is made of SiO 2 , Si, SiC and Y 2 O 3 The other ring bodies are made of SiO 2 or Al 2 O 3 Made.

[0018] A focusing ring lifting structure is used for lifting the 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.

[0019] Optionally, the focusing ring lifting structure includes:

[0020] An ejector component, the ejector component comprising a plurality of ejectors correspondingly and drivingly connected to the respective ring bodies of the focusing ring;

[0021] 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;

[0022] 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;

[0023] A driving device is used to drive the pitch-changing plate to move back and forth along a preset direction.

[0024] Optionally, 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 line between the two ends of the variable pitch 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.

[0025] 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 changing notch.

[0026] Optionally, 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.

[0027] Optionally, the focus ring lifting structure further includes a fixed seat, and the pitch variable plate is disposed on the fixed seat so as to be reciprocatingly movable along an axial direction perpendicular to the focus ring.

[0028] Optionally, a slider is provided on one of the fixed seat and the pitch-changing plate, and a guide rail is provided on the other of the fixed seat and the pitch-changing plate, and the slider and the guide rail are slidably matched to make the pitch-changing plate slidably connected to the fixed seat.

[0029] Optionally, the focusing ring lifting structure includes:

[0030] 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;

[0031] 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.

[0032] 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 both ends of the bellows are respectively sealed and connected to the fixed flange and the base of the rod body.

[0033] Optionally, the ejector pins are arranged at intervals in the circumferential direction around the axis of the focusing ring.

[0034] 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.

[0035] Optionally, the focusing ring lifting structure further includes a positioning sleeve shaft, the positioning sleeve shaft is used to be fixedly connected to the etching machine, and the positioning sleeve shaft is used to guide and position the ejector pin.

[0036] An etching machine comprises a focusing ring as described in any one of the above items and a focusing ring lifting structure as described in any one of the above items.

[0037] A plasma etching device comprises the etching machine as described above.

[0038] It can be seen from the above technical scheme 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 being lifted as a whole is divided into several small spaces by each ring body, and each small space is connected only by a small slit 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

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0040] Figure 1 It is a schematic diagram of the structure after the focusing ring is lifted in the prior art;

[0041] Figure 2 A schematic diagram of a partial structure of a focusing ring provided in an embodiment of the present invention;

[0042] Figure 3 A schematic diagram of a partial structure of a focusing ring provided in another embodiment of the present invention;

[0043] Figure 4 A schematic diagram of a partial structure of a focusing ring provided in yet another embodiment of the present invention;

[0044] Figure 5 A partial cross-sectional view of an etching machine equipped with a focus ring provided by an embodiment of the present invention;

[0045] Figure 6 A partial cross-sectional view of an etching machine equipped with a focus ring provided by an embodiment of the present invention before the focus ring is consumed and lifted up;

[0046] Figure 7 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;

[0047] Figure 8 A cross-sectional view of a focus ring lifting structure provided by an embodiment of the present invention after being cut through a cross section passing through the axis of the focus ring;

[0048] Fig. 9 A cross-sectional view of a focus ring lifting structure provided by an embodiment of the present invention cut along a cross-section perpendicular to the radial direction of the focus ring;

[0049] Fig.10 A top view of a focus ring lifting structure provided by an embodiment of the present invention;

[0050] Fig.11 A partial cross-sectional view of a focus ring lifting structure provided in an embodiment of the present invention at a variable pitch transmission mechanism;

[0051] Fig.12 A schematic structural diagram of a focus ring lifting structure provided by an embodiment of the present invention when a pitch-changing plate of a pitch-changing transmission mechanism is in an initial state;

[0052] Fig.13 A schematic structural diagram of a focus ring lifting structure provided by an embodiment of the present invention during the movement of a pitch-changing plate of a pitch-changing transmission mechanism;

[0053] Fig.14 A cross-sectional view of a focus ring lifting structure provided by another embodiment of the present invention after being cut through a cross section passing through the axis of the focus ring;

[0054] Fig.15 A cross-sectional view of a focus ring lifting structure provided by another embodiment of the present invention after being cut along a cross-section perpendicular to the radial direction of the focus ring;

[0055] Figures 16 to 20 In each stage of the lifting process of the focusing ring lifting structure provided by another embodiment of the present invention, Fig.15 A local enlarged schematic diagram of point A in the figure.

[0056] In the figure:

[0057] 10 is the focusing ring; 1 to 5 are the ring bodies;

[0058] 20 is a focus ring lifting structure with equal lifting; 21, 211, 212, 213, 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 plate; 261, 262, 263, 264 are pitch 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;

[0059] 20' is a focusing ring lifting structure for orderly lifting; 21', 211', 212', 213', 214' are ejectors; 22' is a positioning sleeve shaft; 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 stepping motor; 28' is a motor cover;

[0060] 30 is a wafer;

[0061] 40 is an electrostatic chuck;

[0062] 50 is the middle ring;

[0063] 60 is the edge ring;

[0064] 70 is an insulating ring;

[0065] 80 is the base. DETAILED DESCRIPTION

[0066] One of the cores of the present invention is to provide a focusing ring whose structural design 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.

[0067] Another core of the present invention is to provide a focusing ring lifting structure matching 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.

[0068] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0069] See also Figure 2 , Figure 2 A schematic diagram of the partial structure of a focusing ring provided in one embodiment of the present invention.

[0070] A focusing ring 10 is disclosed in an embodiment of the present invention. The focusing ring 10 includes a plurality of ring bodies arranged in a stacked manner, 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 arranged independently of each other, 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 slit 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. 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.

[0071] 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 up. Figures 5 to 7As shown, the focusing ring 10 includes 5 layers of ring bodies, which are 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 2, 3, 4, 6, 7... and other positive integers. The focusing ring 10 is arranged in a space surrounded by the wafer 30, the electrostatic chuck 40, the middle 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, so as to change the distribution and morphology of the plasma sheath in the edge area of ​​the wafer 30.

[0072] The bottom ring body 5 of the focus ring 10 can be supported by the electrostatic chuck 40 and the edge ring 60, or can be supported by the focus ring lifting structure 20. Figure 5 As shown, there is a slit between the side A (inner side) of the focus ring 10 and the middle ring 50, and there is a slit between the side B (outer side) of the focus ring 10 and the edge ring 60, to ensure that during the lifting process, both sides A / B of the focus ring 10 will not be rubbed, reducing the risk of generating particles. In some structures, the middle ring 50 may not be provided, but may be replaced by the ceramic outer ring of the electrostatic chuck 40.

[0073] After a certain radio frequency time (RFH), the uppermost ring body 1 of the focusing ring 10 is etched, such as Figure 6 As shown in FIG. 1 , the etched amount S is larger on the inside and smaller on the outside, and the maximum etched height H appears on the inside. When the etched amount S is detected to reach a preset threshold, in order to maintain process stability, the focus ring lifting structure 20 drives the focus ring 10 to rise, and the rising height is the maximum etched height H, H = H1 + H2 + H3 + H4 + H5, as shown in FIG. Figure 7 shown.

[0074] To sum up, 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 being 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 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 breakage of the focusing ring 10.

[0075] like Figure 2As shown, the axial size (thickness) of the ring body 1 located at the top layer is larger than the axial size (thickness) of the other ring bodies 2, 3, 4, 5 so as to withstand the etching during the production process. The axial sizes of the other ring bodies are smaller than the axial size of the ring body located at the top layer, and are only used to divide the space below the ring body located at the top layer after being lifted. Of course, the axial sizes of the other ring bodies except the ring body located at the top layer may be the same or different. In the embodiment of the present invention, the axial sizes of the other 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.

[0076] 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 may be perpendicular to the axis of the ring body or may not be perpendicular to the axis of the ring body. The tapering direction and cone angle of the conical surface between the ring bodies may be the same or different. Figure 2 As shown, in a specific embodiment of the present invention, the mating surface between 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.

[0077] 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 a plane, a curved surface, and a zigzag surface.

[0078] Specifically, Figure 3 As shown, in another embodiment provided by the embodiment of the present invention, one of the mating surfaces between the above-mentioned 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.

[0079] like Figure 4 As shown, 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 an annular manner along the radial direction of the ring body, and each annular abutment surface is arranged in sequence and spaced apart in a step shape along the axial direction of the ring body.

[0080] It should be noted that the above-mentioned plane, conical surface or concave-convex surface structure can be Figure 3 or Figure 4 The mating surfaces shown can be mixed as long as it can be ensured that two adjacent ring bodies can be stacked on each other.

[0081] Figure 3 and Figure 4The two matching surface solutions shown can further divide the small space between the two layers of ring bodies into multiple smaller spaces, which has a better effect on preventing arc discharge. However, due to the limitations of part design thickness and material brittleness, it is generally only used in working conditions with a small number of layers.

[0082] Preferably, in the embodiment of the present invention, the materials of the various ring bodies of the focusing ring 10 can be the same or different. The ring body at the top layer is made of SiO 2 , Si, SiC and Y 2 O 3 The other rings are made of SiO 2 or Al 2 O 3 Made.

[0083] An embodiment of the present invention further provides a focusing ring lifting structure, which is used for lifting the focusing ring 10 as described in the above embodiment. The focusing ring lifting structure includes a driving unit and a plurality of executing units. The driving unit is transmission-connected to the executing units. The executing units are arranged one-to-one with the respective ring bodies of the focusing ring 10. Each executing unit may have a plurality of executing ends, and the executing ends are arranged at intervals along the circumference of the corresponding ring body of the focusing ring 10. Preferably, the executing ends are evenly arranged along the circumference of the corresponding ring body of the focusing ring 10. Alternatively, a focusing ring 10 may be configured with a plurality of focusing ring lifting structures arranged at intervals along the circumference of the focusing ring 10. The corresponding executing units of the respective focusing ring lifting structures act synchronously. The driving unit of the focusing ring lifting structure is used to drive the executing units to lift the respective ring bodies of the focusing ring 10 to a preset height according to preset instructions.

[0084] Specifically, Figures 8 to 11 In the illustrated embodiment, 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.

[0085] Among them, the ejector pin component includes a plurality of ejector pins 21 which are transmission-connected to the respective ring bodies of the focus ring 10, and 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 may be the same as the number of the ring bodies of the focus ring 10, or the number of the ejector pins 21 may be 2 times, 3 times, etc., of 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, and the upper end surfaces of the ejector pins 21 are used for contacting and cooperating 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 at intervals along the circumferential direction around the axis of the focus ring 10.

[0086] like Figure 8 and Fig. 9As shown, the focus ring lifting structure 20 with even lifting is installed on the base 80 of the etching machine, passes through the insulating ring 70, the middle ring 50 and the edge ring 60 from bottom to top, and finally contacts each ring body of the focus ring 10 only through the tiny ejector pins 21, driving each ring body of the focus ring 10 to realize even lifting upward. Among them, the base 80 is a partition between the vacuum environment and the atmospheric environment, and the part of the focus ring lifting structure 20 with even lifting below the base 80 is in the atmospheric environment, and the part above the base 80 is in the vacuum environment.

[0087] Preferably, in order to ensure the movement stability of the ejector pin 21, Fig. 9 As shown, 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.

[0088] The pitch-changing transmission mechanism includes a pitch-changing plate 26 and a transmission rod 23. A transmission structure corresponding to each transmission rod 23 is arranged on the pitch-changing plate 26. The transmission rod 23 is connected to the ejector pin 21. One 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 in proportion according to the arrangement sequence of the corresponding ring bodies from top to bottom in the focus ring 10. That is, when the pitch-changing plate 26 moves along an axial direction perpendicular to the focus ring 10, the movement distance of each ejector pin 21 decreases in proportion according to the arrangement sequence 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-changing plate 26 moves, each ejector pin 21 also moves accordingly, but the movement distances of each ejector pin 21 are different.

[0089] The moving direction of the pitch change plate 26 is as follows: Figures 8 to 11 The pitch variable plate 26 shown in the figure is described as being in a rectangular shape. The actual moving direction of the pitch variable plate 26 is not limited to the 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 one-to-one corresponding to each other, that is, the structure of the pitch variable plate 26 can be designed to enable it to simultaneously drive multiple groups of ejector pin components.

[0090] 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 of the fixed flange 231 and the base 80. 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 member. The two ends of the bellows 232 are respectively sealed and connected to 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 be compressed to maintain stable vertical movement, which also meets the requirement that the part above the base 80 is in a vacuum environment.

[0091] 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 needs to be provided to guide the ejector pin 21 and / or the transmission rod 23.

[0092] The driving device is used to drive the pitch plate 26 to move back and forth along a preset direction. The moving path of the pitch plate 26 can be a straight line or a curve. 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 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 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 driving device adopts a push rod type stepper motor 29, and the push rod type stepper motor 29 integrates a stepper motor and a high-precision screw structure, directly converts the rotational motion of the stepper motor into a high-precision linear motion, and has a compact structure. The output shaft of the push rod type stepper motor 29 is fixed on the pitch plate 26, and pushes the pitch plate 26 to achieve controllable, high-precision, horizontal movement.

[0093] Preferably, in an embodiment of the present invention, Fig.11 As shown, the transmission structure is a pitch-changing slot 261-264, a follower shaft 25 is arranged 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-changing slot 261-264 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-changing slot 261-264 and the horizontal plane is proportionally reduced in sequence according to the arrangement order of the corresponding ring bodies from top to bottom in the focusing ring 10, from Fig.11It can be seen that for the focusing ring 10 with four-layer ring bodies, the pitch-changing plate is provided with four pitch-changing slots 261-264, and the four pitch-changing slots 261-264 are arranged in sequence from right to left, and the leftmost pitch-changing slot 264 is transmission-connected to the uppermost ring body of the focusing ring 10, and the angle between the connecting line of the two ends of the leftmost pitch-changing slot 264 and the horizontal plane is also the largest among the four pitch-changing slots 261-264, and the angles between the connecting lines of the two ends of the remaining pitch-changing slots 263, 262, 261 and the horizontal plane decrease in sequence.

[0094] The "equal distribution" of the focus ring lifting structure 20 of the embodiment of the present invention is achieved by relying on the center curve function of the variable pitch notches 261-264 of the variable pitch plate 26, such as Fig.11 As shown. The motor drives the pitch plate 26 to move along the X direction in the figure, and the follower shaft 25 embedded in the pitch slots 261-264 is restricted to move only in the Z direction in the figure. The relationship between the movement amounts of the two is controlled by the center curve function of the pitch slots 261-264. By setting the center curve function of equal proportion, the "equal distribution" of the focus ring lifting structure 20 of equal lifting can be achieved, that is, the size of the gap below each ring body is always equal during the lifting process.

[0095] Through the design of the above-mentioned pitch-changing slots 261-264, when the driving device drives the pitch-changing plate 26 to move left and right, since the pitch-changing slots 261-264 are inclined and have a central curve function of equal proportion, they can 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 through the sliding cooperation with the follower shaft 25, that is, when the driving device drives the pitch-changing plate 26 to move right, the ejector pin 21 and the transmission rod 23 move upward, and when the driving device drives the pitch-changing plate 26 to move left, the ejector pin 21 and the transmission rod 23 move downward. In addition, since the angles between the pitch-changing slots 261-264 and the horizontal plane decrease in equal proportion from left to right, during the movement of the pitch-changing plate 26, the moving distances of the ring bodies 1-4 of the focus ring 10 also decrease from top to bottom, so as to ensure that a gap can be generated below each ring body and each gap is always equal.

[0096] The above-mentioned up, down, left, right, X, and Z are only for the convenience of explaining the movement direction of the pitch change plate 26, the ejector pin 21, and the transmission rod 23. Fig.11 In the actual application process, the movement direction of the pitch plate 26, the ejector pin 21 and the transmission rod 23 is determined according to the actual arrangement.

[0097] In the above embodiment, when the transmission structure is a pitch-changing slot 261~264, the above-mentioned positioning component includes a positioning sleeve 24, a guide hole 241 is arranged in the positioning sleeve 24, and a guide groove connected to the guide hole 241 is arranged on the side wall corresponding to the positioning sleeve 24 and the guide hole 241, and the transmission rod 23 is slidably matched with the guide hole 241. In the embodiment of the present invention, the base of the rod body 233 of the transmission rod 23 is slidably matched 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-changing slots 261~264.

[0098] 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 is reduced in proportion according to the arrangement order of the corresponding ring bodies from top to bottom in the focusing ring 10.

[0099] As preferably, Fig.10 and Fig.11 As shown, the equally-lifted focus ring lifting structure also includes a fixed seat 28, and the variable pitch plate 26 can be reciprocated on the fixed seat 28 along an axial direction perpendicular to the focus ring 10. The fixed seat 28 provides an installation position and support for the variable pitch plate 26 to ensure the stability of the movement of the variable pitch plate 26.

[0100] Specifically, Fig.11 As shown, in the embodiment of the present invention, the fixed seat 28 and the pitch-changing plate 26 cooperate with each other 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-changing plate 26 and a guide rail 271 provided on the other of the fixed seat 28 and the pitch-changing plate 26. The slider 272 slidably cooperates with the guide rail 271 to make the pitch-changing plate 26 slidably connected with the fixed seat 28. The guide rail 271 cooperates with the slider 272 to constrain the slider, thereby ensuring that the pitch-changing plate 26 can move relative to the fixed seat 28 along a preset direction ( Fig.11 left and right directions in the image.

[0101] Specifically, in Figure 8 and Fig. 9 In the embodiment shown, 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. Correspondingly, four ejector pins are also designed: ejector pin 211, ejector pin 212, ejector pin 213, and ejector pin 214. The four ring bodies correspond to the four ejector pins one by one and contact each other. The bottoms of the four ejector pins are respectively connected to the transmission rod 23, and the transmission rod 23 is respectively controlled by the pitch-changing slot 261, the pitch-changing slot 262, the pitch-changing slot 263, and the pitch-changing slot 264 through the follower shaft 25. Fig.11As shown, the central curve function of the four variable pitch notches adopts the simplest linear function Z = n×X.

[0102] As Fig.11 and Fig.12 shown, in the initial state, each follower shaft 25 is on a horizontal line, evenly distributed among them, and the distance between every two follower shafts 25 is S. At the variable pitch notch 261 (the rightmost variable pitch notch), the central curve function is defined as: Z = X, where α1 = 45°, corresponding to the ring body 4 of the lowermost layer of the focusing ring 10. At the variable pitch notch 262, the central curve function is defined as: Z = 2×X, where α2 = 26.565°, corresponding to the ring body 3 of the focusing ring 10. At the variable pitch notch 263, the central curve function is defined as: Z = 3×X, where α3 = 18.435°, corresponding to the ring body 2 of the focusing ring 10. At the variable pitch notch 264, the central curve function is defined as: Z = 4×X, where α4 = 14.036°, corresponding to the ring body 1 of the uppermost layer of the focusing ring 10.

[0103] As Fig.13 shown, in the moving state, the variable pitch plate 26 moves an arbitrary distance H in the X direction, 0 < H ≤ Htotal, where Htotal is the maximum moving distance of the variable pitch plate 26 in the X direction. At this time, the follower shafts 25 at each of the variable pitch notches 261 - 264 will move heights of H, 2H, 3H, and 4H from right to left in sequence, and the respective layers of the ring body of the corresponding focusing ring 10 will rise by H, 2H, 3H, and 4H from bottom to top in sequence. The height of the small space divided by the bottom of each two layers of the ring body and the bottom of the lowermost layer of the ring body is H, effectively achieving the purpose of equalizing the lifting.

[0104] In another embodiment, as Fig.14 and 15 shown in the embodiment, a focusing ring lifting structure 20' for sequential lifting is provided. Different from the above-mentioned focusing ring lifting structure 20 for equalizing lifting, the driving mode of the focusing ring lifting structure 20' for sequential lifting is not to make each ring body move simultaneously, but to make each ring body start to move in sequence one after another.

[0105] As Figures 14 to 16As shown, 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 the ring bodies of the focus ring 10, or can be a positive integer multiple of the number of the ring bodies of the focus ring 10, the gap between the pins 21' and the corresponding ring body increases arithmetic progression according to the arrangement sequence of the corresponding ring bodies from top to bottom in the focus ring 10, the pins 21' serve as the executor 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 do not contact the uppermost ring body 1, 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 sequence of the ring bodies from top to bottom.

[0106] like Fig.14 and Fig.15 As shown, in this embodiment, the orderly lifting focus ring lifting structure 20' is installed on the base 80 of the etching machine, passes through the insulating ring 70, the middle ring 50 and the edge ring 60 from bottom to top, and finally contacts the various ring bodies of the focus ring 10 through the ejector pin 21', driving the various ring bodies of the focus ring 10 to achieve orderly upward lifting action. Among them, the base 80 is a partition between the vacuum environment and the atmospheric environment, and the part of the orderly lifting focus ring lifting structure 20' below the base 80 is in the atmospheric environment, and the part above is in the vacuum environment.

[0107] As a preferred embodiment, in order to ensure the movement stability of the ejector pin 21 ', as Fig.14 and Fig.15 As shown, 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' reciprocates along a preset direction.

[0108] The driving device is connected to the lifting seat 23' through the transmission rod 24' to drive the lifting seat 23' to reciprocate 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 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.

[0109] In a specific embodiment of the present invention, the driving device adopts a push rod type stepper motor 27', which integrates a stepper motor and a high-precision screw structure, directly converts the rotational motion of the stepper motor into a high-precision linear motion, and has a compact structure. The output shaft of the push rod type stepper motor 27' is fixed on the lifting seat 23', pushing the lifting seat 23' to achieve controllable, high-precision, vertical movement.

[0110] 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' installed 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 to form a vacuum environment, thereby placing the push rod type stepper motor 27' in a vacuum environment to prevent the push rod type stepper motor 27' from being affected by dust and impurities, thereby 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.

[0111] Under certain working conditions, there is also a partial vacuum environment at the bottom of the base 80. In order to facilitate the design of the motor fixing position, a motor cover 28' is added to isolate the atmospheric environment and form a partial vacuum environment to accommodate the push rod type stepper motor 27'. Of course, the motor cover 28' is not necessary. Under certain working conditions, the motor cover 28' may not be designed.

[0112] 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 of the fixed flange 241' and the base 80. 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, which also meets 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 groove, and the base of the rod body 243' is provided with a stop pin 25', which cooperates with the limiting groove to prevent the transmission rod 24' from rotating.

[0113] The "orderly" in the above-mentioned orderly lifted focusing ring lifting structure 20' refers to the gradual transition of the division form of the lifting space from large at the top and small at the bottom to being consistent at the top and bottom and finally stable. During the lifting process, the various ring bodies of the focusing 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 focusing ring 10 is: the height of the small space divided above the focusing ring 10 reaches the designed maximum height Hmax. For a structure with N layers of focusing rings 10, Hmax = Htotal / N. Moreover, after any layer of focusing ring 10 is lifted, it and all the focusing 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.

[0114] The process of orderly lifting is described below in conjunction with specific embodiments.

[0115] like Fig.16 As shown, in the illustrated embodiment, the focus ring 10 is in a non-lifted state, and the focus ring 10 is composed of four parts, namely, a ring body 1, a ring body 2, a ring body 3, and a ring body 4, which are stacked in sequence from top to bottom. Therefore, correspondingly, four ejector pins 211', 212', 213', and 214' are provided, and the top of each ejector pin has a different height, from high to low, they are respectively 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.

[0116] like Fig.16 As shown in the figure, in the free state, the clearance values ​​designed between the four rings and the four ejector pins are J1, J2, J3 and J4, respectively, where J1<J2<J3<J4. The maximum height of the small space formed by the division is defined as Hmax, then the above J1≥0, J2=J1+Hmax, J3=J2+Hmax, J4=J3+Hmax, J1, J2, J3 and J4 increase in an arithmetic progression, realizing "orderly" jacking.

[0117] At the same time, for ease of understanding, the heights of the small spaces formed by the division are defined as H1, H2, H3, and H4 from top to bottom. Fig.16 As shown, in the initial state, when the focus ring 10 is not lifted, H1 = H2 = H3 = H4 = 0. Fig. 20 As shown, in the final state, when all the ring bodies of the focus ring 10 are 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.

[0118] like Fig.17As shown, 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 up, at this time the lifted height of the ring body 1 is H11=Htotal1, H21=H31=H41=0, the gap J11 between the ejector pin 211' and the ring body 1 is 0, at the same time, the ejector pin 212', the ejector pin 213' and the ejector pin 214' also move upward synchronously, the gap J21 between the ejector pin 212' and the ring body 2 is (Hmax-Htotal1)≥0, the gap J31 between the ejector pin 213' and the ring body 3 is J21+Hmax, and the gap J41 between the ejector pin 214' and the ring body 4 is J31+Hmax.

[0119] like Fig.18 As shown, 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.

[0120] like Fig.19 As shown, 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 up, and 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×Hmax , 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.

[0121] like Fig. 20As shown, at the moment shown in the figure, when the total lifting height Htotal4 satisfies 3×Hmax<Htotal4≤4×Hmax, the ring body 1, the ring body 2, the ring body 3 and the ring body 4 are all lifted up, and at this time, the gap H14 between the ring body 1 and the ring body 2, the gap H24 between the ring body 2 and the ring body 3, and the gap H34 between the ring body 3 and the ring body 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.

[0122] 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 .

[0123] The present invention also provides an etching machine, such as Figure 5 The etching machine includes the focusing ring 10 and the focusing ring lifting structure as described in the above embodiment. The focusing ring lifting structure can be an evenly lifted focusing ring lifting structure 20 or an orderly lifted focusing ring lifting structure 20'. Since the etching machine adopts the focusing ring 10 and the focusing ring lifting structure in the above embodiment, please refer to the above embodiment for the technical effect of the etching machine.

[0124] like Figure 5 As shown, in the above-mentioned etching machine, the focus 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 of the focus ring 10 is higher than the upper surface of the wafer 30, which serves the purpose of changing 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 there is a gap between the side B and the edge ring 60, which ensures that there is no friction on both sides A / B of the focus ring 10 during the lifting process, reducing the risk of particle generation. In some structures, the intermediate ring 50 may not be provided, but instead replaced by the ceramic outer ring of the electrostatic chuck 40.

[0125] An embodiment of the present invention further provides a plasma etching device, which includes an etching machine as described in the above embodiment. Since the plasma etching device adopts the etching machine in the above embodiment, the technical effect of the plasma etching device please refer to the above embodiment.

[0126] 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 or similar parts between the various embodiments can be referenced to each other.

[0127] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified, and these 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 focus ring lifting structure, used for lifting the focus ring according to any one of claims 1 to 9, characterized in that: The focusing ring lifting structure includes a driving unit and a plurality of executing units, wherein the driving unit is transmission-connected to each of the executing units, and each of the executing units is arranged in a one-to-one correspondence with each ring body of the focusing ring. 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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