A device for adjusting the etching uniformity of a wafer edge

Abstract

This invention discloses a device for adjusting the etching uniformity of wafer edges, used to raise and lower a focusing ring within a vacuum reaction chamber. A base is positioned within the vacuum reaction chamber, and an electrostatic chuck is mounted on the base. The focusing ring surrounds the outer periphery of the electrostatic chuck. The device includes: a lifting component comprising N sets of scissor arm units stacked vertically; a fixed base with a first guide rail, a first fixed pivot group on a first side of the first guide rail, and a first sliding pivot group that can slide along the first guide rail on a second side; and a lifting platform with a second guide rail extending parallel to the first guide rail, a second fixed pivot group on a first side of the second guide rail, and a second sliding pivot group that can slide along the second guide rail on a second side. When N is greater than or equal to 2, adjacent scissor arm units achieve motion coupling through staggered hinge nodes. This invention ensures long-term uniformity of plasma distribution at the wafer edge while maintaining process continuity.

Description

Technical Field

[0001] This utility model relates to semiconductor wafer equipment, and more particularly to a device for adjusting the uniformity of wafer edge etching. Background Technology

[0002] In plasma etching processes, the focusing ring, a key component surrounding the wafer substrate, plays a crucial role in confining plasma distribution to improve etching uniformity at the wafer edges. However, due to continuous exposure to a high-density plasma environment during the process, the surface material of this ring undergoes progressive loss due to ion bombardment and chemical reactions. This loss causes the height of the focusing ring's upper surface to gradually fall below the wafer's supporting surface, disrupting the original plasma confinement boundary conditions. Consequently, this disrupts the uniformity of plasma distribution in the edge regions, ultimately leading to significant fluctuations in the etching rate. This directly affects the consistency of submicron-level pattern transfer, compromising the precision and long-term stability of the etching process.

[0003] To address the aforementioned issues, existing technologies generally employ a replacement strategy involving shutting down and disassembling the reaction chamber. Specifically, this requires interrupting the etching process, breaking the vacuum, manually removing the chamber cover, removing the worn focusing ring, and installing a new component. While this method can restore the ring height, it has several limitations: First, frequent vacuum disruption and reconstruction processes can lead to the re-release of contaminants adsorbed on the inner wall of the chamber, increasing the risk of particle defects on the wafer surface; second, frequent disassembly and reassembly can degrade the chamber's sealing performance; and third, the related maintenance cycle conflicts with the continuous production requirements of the etching process, significantly reducing the overall utilization rate of the equipment and increasing maintenance time and economic costs.

[0004] Therefore, there is an urgent need to develop a device that can dynamically compensate for the height of the focusing ring in a vacuum environment, so as to ensure the long-term uniformity of plasma distribution at the wafer edge while maintaining process continuity. Utility Model Content

[0005] The purpose of this invention is to provide a device for adjusting the etching uniformity of wafer edges, which solves various problems caused by the need to replace the focusing ring due to wear during existing plasma etching of wafers.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows:

[0007] A device for adjusting the etching uniformity of wafer edges, used to raise and lower a focusing ring within a vacuum reaction chamber, wherein a base is disposed within the vacuum reaction chamber, an electrostatic chuck is disposed on the base, and the focusing ring is arranged around the outer periphery of the electrostatic chuck, comprising:

[0008] The lifting component includes N sets of scissor arm units stacked in a vertical direction, where N is a positive integer ≥1;

[0009] A fixed base is provided with a first guide rail. A first fixed pivot group is provided on a first side of the first guide rail, and a first sliding pivot group that can slide along the first guide rail is provided on a second side.

[0010] The lifting platform is provided with a second guide rail extending parallel to the first guide rail. A second fixed pivot group is provided on the first side of the second guide rail, and a second sliding pivot group is provided on the second side that can slide along the second guide rail.

[0011] Among them, the bottom and top ends of the N groups of scissor arm units are respectively hinged to the first fixed pivot group, the first sliding pivot group, the second fixed pivot group, and the second sliding pivot group; when N is greater than or equal to 2, the adjacent scissor arm units achieve motion coupling through staggered hinge nodes.

[0012] The beneficial effects of the device for adjusting the uniformity of wafer edge etching provided by this utility model are as follows: after the focusing ring is worn out after being etched for a period of time, the driving mechanism acts on the first sliding pivot group, causing it to slide horizontally along the first guide rail, forcing the scissor arm unit to deform and unfold, and finally driving the focusing ring to rise and fall smoothly in the vertical direction, so as to keep the upper surface of the focusing ring not lower than the upper surface of the wafer, thereby ensuring the uniformity of wafer etching.

[0013] In one or more embodiments of this utility model, each group of scissor arm units includes two intersecting links of the same length, and a central hinge shaft is provided at the intersection of the two links.

[0014] In one or more embodiments of this utility model, each of the connecting rods corresponds one-to-one with and is hinged to the connecting rods on the adjacent scissor arm unit.

[0015] In one or more embodiments of this utility model, the first fixed pivot group and the second fixed pivot group both include a fixed rotating shaft, the first sliding pivot group includes a first fixed shaft and a first pulley, the second sliding pivot group includes a second fixed shaft and a second pulley, the first fixed shaft and the first pulley are coaxially and fixedly connected, and the second fixed shaft and the second pulley are coaxially and fixedly connected.

[0016] In one or more embodiments of this utility model, the first guide rail and the second guide rail are closed guide rail structures. The cross-section of the first guide rail and the second guide rail is U-shaped and has a guide groove. The fixed pivot of the first fixed pivot group and the fixed pivot group are respectively in rolling cooperation with the guide groove of the first guide rail and the second guide rail. A limiting structure is provided between the outer edge of the fixed pivot and the inner wall of the guide groove.

[0017] In one or more embodiments of this utility model, the pulleys of the first sliding pivot group and the second sliding pivot group respectively form a compound kinematic pair with the guide grooves of the first guide rail and the second guide rail. The rotation axis of the pulley is perpendicular to the extension direction of the first guide rail and the second guide rail, and the outer edge of the pulley forms a rolling contact with the bottom surface of the guide groove, and the side wall of the pulley forms a sliding contact with the side wall of the guide groove.

[0018] In one or more embodiments of the present invention, a position translation detector is provided on the first fixed pivot group, and the position translation detector is used to detect the translation distance of the first sliding pivot group.

[0019] In one or more embodiments of this utility model, a support member is further included, the support member comprising:

[0020] An aluminum ring is disposed at the bottom of the focusing ring and is fixedly connected to the lifting platform;

[0021] An isolation ring is disposed on the circumferential outside of the base, and the isolation ring is located on the base.

[0022] In one or more embodiments of this utility model, the guide groove has a first position and a second position, the first fixed pivot group is located at the first position, the first sliding pivot group can slide to the second position, and the distance between the first extreme position and the second extreme position is adjustable.

[0023] In one or more embodiments of this utility model, an isolation sleeve is further included, which penetrates the base and is sleeved on the outside of the N sets of scissor arm units. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the device for adjusting the etching uniformity of the wafer edge according to this utility model;

[0025] Figure 2 This is a schematic diagram of the lifting component when N=1 in an embodiment of this utility model;

[0026] Figure 3 This is a schematic diagram of the lifting component when N=2 in an embodiment of this utility model;

[0027] Figure 4 This is a schematic diagram showing the lifting height of the focusing ring in an embodiment of the present invention.

[0028] Reference numerals: 1. Vacuum reaction chamber; 2. Focusing ring; 3. Base; 4. Electrostatic chuck; 5. Scissor arm unit; 51. Connecting rod; 52. Central hinge point; 53. Isolation sleeve; 6. Fixed base; 61. First guide rail; 611. First fixed pivot group; 612. First sliding pivot group; 7. Lifting platform; 71. Second guide rail; 711. Second fixed pivot group; 712. Second sliding pivot group; 8. Support component; 81. Aluminum ring; 82. Isolation ring; 9. Detector; 91. Wafer. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this utility model pertains. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but does not exclude other elements or objects.

[0030] The following is in conjunction with the appendix Figure 1 - Appendix Figure 4 The specific embodiments of this utility model will be further described in detail below.

[0031] Reference Figures 1-2 This invention discloses a device for adjusting the etching uniformity of wafer edges, used to raise and lower a focusing ring 2 within a vacuum reaction chamber 1. A base 3 is disposed within the vacuum reaction chamber 1, and an electrostatic chuck 4 is mounted on the base 3. The focusing ring 2 is arranged around the outer periphery of the electrostatic chuck 4. The vacuum reaction chamber 1 can be the reaction chamber of a capacitively coupled plasma etching (CAPE) device or an inductively coupled plasma etching (ICP) device, etc. An electrostatic electrode is disposed inside the electrostatic chuck 4 to generate electrostatic attraction, thereby supporting and fixing the wafer 91 during the process.

[0032] A device for adjusting the etching uniformity of wafer edges includes a lifting component, a fixed base 6, and a lifting platform 7. The lifting component includes N sets of scissor arm units 5 stacked vertically, where N is a positive integer ≥ 1. The fixed base 6 is provided with a first guide rail 61, a first fixed pivot group 611 on a first side of the first guide rail 61, and a first sliding pivot group 612 that can slide along the first guide rail 61 on a second side. The lifting platform 7 is provided with a second guide rail 71 extending parallel to the first guide rail 61, a second fixed pivot group 711 on a first side of the second guide rail 71, and a second sliding pivot group 712 that can slide along the second guide rail 71 on a second side; wherein the bottommost and topmost endpoints of the N sets of scissor arm units 5 are respectively hinged to the first fixed pivot group 611, the first sliding pivot group 612, the second fixed pivot group 711, and the second sliding pivot group 712.

[0033] Reference Figure 3 When N is greater than or equal to 2, adjacent scissor arm units 5 achieve motion coupling through staggered hinge nodes.

[0034] In one or more embodiments of this utility model, a support member 8 is further included. The support member 8 includes an aluminum ring 81 and an isolation ring 82. The aluminum ring 81 is disposed at the bottom of the focusing ring 2 and is fixedly connected to the lifting platform 7. The focusing ring 2 is usually fixed to the aluminum ring 81 by adhesive. The isolation ring 82 is disposed on the circumferential outside of the base 3 and is located on the base 3.

[0035] In one or more embodiments of this utility model, an isolation sleeve 53 is further included, which penetrates the base 3 and is sleeved on the outside of the N sets of scissor arm units 5. In some other embodiments, a sealing sleeve (not shown in the figure) is provided between the isolation sleeve 53 and the base 3. By providing the sealing sleeve, the sealing performance between the isolation sleeve 53 and the base 3 can be guaranteed. The material of the sealing sleeve is, for example, rubber, and this application does not limit it.

[0036] In one or more embodiments of this utility model, each scissor arm unit 5 is composed of a first connecting rod 51 and a second connecting rod 51, which are arranged in an X-shape and have the same geometric length. A central hinge shaft is provided at the intersection of the first connecting rod 51 and the second connecting rod 51, which includes an axial limiting boss and a self-lubricating bearing. The two ends of the first connecting rod 51 respectively form a first hinge hole and a second hinge hole, and the two ends of the second connecting rod 51 respectively form a third hinge hole and a fourth hinge hole. The axes of all the hinge holes are parallel to the horizontal plane.

[0037] In one or more embodiments of this utility model, each connecting rod 51 corresponds one-to-one with and is hinged to the connecting rod 51 on the adjacent scissor arm unit 5. When N≥2, adjacent scissor arm units 5 achieve motion coupling through staggered hinge nodes. Specifically, the fourth hinge hole of the first connecting rod 51 of the upper scissor arm unit 5 and the third hinge hole of the second connecting rod 51 of the lower scissor arm unit 5 are connected by a transition hinge shaft. Anti-loosening springs are provided at both ends of the axial direction of the transition hinge shaft. The distribution position of each hinge node satisfies the following condition: during the deployment of the scissor arm unit 5, the hinge axes of adjacent units are always parallel to each other, avoiding motion interference.

[0038] In one or more embodiments of this utility model, the first fixed pivot group 611 and the second fixed pivot group 711 each include a fixed rotating shaft. The first sliding pivot group 612 includes a first fixed shaft and a first pulley. The second sliding pivot group 712 includes a second fixed shaft and a second pulley. The first fixed shaft and the first pulley are coaxially and fixedly connected, and the second fixed shaft and the second pulley are coaxially and fixedly connected. One end of the fixed rotating shaft is pivotally connected to the connecting rod 51, and the other end is rotatably disposed within the first guide rail 61 and the second guide rail 71. One end of the first fixed shaft and the second fixed shaft are pivotally connected to the connecting rod 51, and the other end is connected to the pulley. The pulley is in rolling connection with the first guide rail 61 and the second guide rail 71.

[0039] In one or more embodiments of this utility model, the first guide rail 61 and the second guide rail 71 are closed guide rail structures. The cross-sections of the first guide rail 61 and the second guide rail 71 are U-shaped and have guide grooves. The fixed rotating shafts of the first fixed pivot assembly 611 and the second fixed pivot assembly 711 are respectively in rolling engagement with the guide grooves of the first guide rail 61 and the second guide rail 71. A limiting structure is provided between the outer edge of the fixed rotating shaft and the inner wall of the guide groove. The limiting structure can be a limiting flange or a limiting flange, used to prevent the fixed rotating shaft from moving off-center within the first guide rail 61 or the second guide rail 71.

[0040] In one or more embodiments of this utility model, the pulleys of the first sliding pivot group 612 and the second sliding pivot group 712 form a compound kinematic pair with the guide grooves of the first guide rail 61 and the second guide rail 71, respectively. The rotation axis of the pulley is perpendicular to the extension direction of the first guide rail 61 and the second guide rail 71, and the outer edge of the pulley forms a rolling contact with the bottom surface of the guide groove, and the side wall of the pulley forms a sliding contact with the side wall of the guide groove.

[0041] In one or more embodiments of the present invention, the guide groove has a first position and a second position, the first fixed pivot group 611 is located at the first position, the first sliding pivot group 612 can slide to the second position, and the distance between the first extreme position and the second extreme position is adjustable.

[0042] In one or more embodiments of this utility model, a position translation detector 9 is provided on the first fixed pivot assembly 611, which is used to detect the translation distance of the first sliding pivot assembly 612. Specifically, the position translation detector 9 is integrated at the fixed shaft end of the first fixed pivot assembly 611, which includes a detection scale, a sensing element, and a signal processing unit. The detection scale is rigidly fixed to the upper surface of the fixed base 6 along the extension direction of the first guide rail 61, and the surface is provided with periodically distributed detection marks, the spacing of which matches the unfolding resolution of the scissor arm unit 5. The sensing element is fixed to the side of the first sliding pivot assembly 612 by a mounting bracket, and includes at least two non-contact displacement sensors symmetrically arranged, respectively aligned with the axial and radial reference planes of the detection scale. The signal processing unit is located in a control box outside the vacuum reaction chamber 1 and is electrically connected to the sensing component through a cavity-penetrating wire.

[0043] In one or more embodiments of this utility model, the driving structure for driving the first sliding pivot assembly 612 to move in the horizontal direction is not limited, such as an electric cylinder.

[0044] Reference Figure 4 The specific detection principle is as follows: by directly detecting the horizontal translation of the first sliding pivot group 612, the real-time height compensation of the focusing ring 2 can be indirectly calculated.

[0045] Taking N=1 as an example, let D be the height of the focusing ring 2, L be the length of the connecting rod 51, l be the distance between the first and second extreme positions, and d be the bottom movement distance of adjacent connecting rods 51. Based on the Pythagorean theorem, we can deduce:

[0046]

[0047] As d approaches l, the maximum height is reached:

[0048]

[0049] To increase the maximum lifting height without changing the number of scissor arm groups, the bottom distance l of the initial link 51 can be increased.

[0050] The specific working principle of this utility model is as follows: After the focusing ring 2 is worn down after being etched for a period of time, the driving mechanism (not shown in the figure) acts on the first sliding pivot group 612, causing it to slide horizontally along the first guide rail 61, forcing the scissor arm unit 5 to deform and unfold. Since the upper and lower ends of the scissor arm unit 5 are respectively hinged to the pivot group of the fixed base 6 and the lifting platform 7, the horizontal sliding component is converted into the vertical displacement of the lifting platform 7 through the X-shaped hinge structure of the scissor arm. The guide rail system ensures no lateral deviation during the unfolding of the scissor arm by constraining the motion trajectory of the sliding pivot group, maintaining the linear accuracy of the lifting motion. Multiple sets of scissor arm units 5 form motion coupling through staggered hinge nodes, so that each layer of the arm body unfolds or folds synchronously, thereby uniformly transmitting the unilateral horizontal driving force to the lifting platform 7, ultimately driving the focusing ring 2 to smoothly rise and fall in the vertical direction, so as to keep the upper surface of the focusing ring 2 not lower than the upper surface of the wafer, thereby ensuring the uniformity of wafer etching. By adopting the solution in the above embodiments, the focusing ring 2 can be raised without opening the chamber or changing the equipment. The height of the focusing ring 2 can be adjusted in a timely manner according to the degree of etching damage to improve the uneven edge etching of the etched wafer.

[0051] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0052] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and connections within two components or interactions between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0053] Unless otherwise expressly specified and limited, "above" or "below" a second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of a second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of a second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0054] Although the embodiments of this utility model have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of this utility model as described in the claims. Moreover, the utility model described herein may have other embodiments and can be implemented or realized in various ways.

Claims

1. A device for adjusting the etching uniformity of a wafer edge, used to raise and lower a focusing ring (2) within a vacuum reaction chamber (1), wherein a base (3) is disposed within the vacuum reaction chamber (1), and an electrostatic chuck (4) is disposed on the base (3), and the focusing ring (2) is disposed around the outer periphery of the electrostatic chuck (4), characterized in that, include: The lifting component includes N sets of scissor arm units (5) stacked in the vertical direction, where N is a positive integer ≥1; The fixed base (6) is provided with a first guide rail (61), a first fixed pivot group (611) is provided on the first side of the first guide rail (61), and a first sliding pivot group (612) that can slide along the first guide rail (61) is provided on the second side. The lifting platform (7) is provided with a second guide rail (71) extending parallel to the first guide rail (61). A second fixed pivot group (711) is provided on the first side of the second guide rail (71), and a second sliding pivot group (712) that can slide along the second guide rail (71) is provided on the second side. Among them, the bottom and top ends of the N groups of scissor arm units (5) are respectively hinged to the first fixed pivot group (611), the first sliding pivot group (612), the second fixed pivot group (711), and the second sliding pivot group (712); when N is greater than or equal to 2, the adjacent scissor arm units (5) achieve motion coupling through staggered hinge nodes.

2. The device for adjusting the etching uniformity of wafer edges according to claim 1, characterized in that, Each scissor arm unit (5) includes two intersecting links (51) of the same length, with a central hinge shaft at the intersection of the two links (51).

3. The device for adjusting the etching uniformity of wafer edges according to claim 2, characterized in that, Each of the links (51) corresponds one-to-one with and is hinged to the link (51) on the adjacent scissor arm unit (5).

4. The device for adjusting the etching uniformity of wafer edges according to claim 2, characterized in that, Both the first fixed pivot group (611) and the second fixed pivot group (711) include a fixed rotating shaft. The first sliding pivot group (612) includes a first fixed shaft and a first pulley. The second sliding pivot group (712) includes a second fixed shaft and a second pulley. The first fixed shaft and the first pulley are coaxially and fixedly connected. The second fixed shaft and the second pulley are coaxially and fixedly connected.

5. The apparatus for adjusting the etching uniformity of wafer edges according to claim 4, characterized in that, The first guide rail (61) and the second guide rail (71) are closed guide rail structures. The cross-section of the first guide rail (61) and the second guide rail (71) is U-shaped and has a guide groove. The fixed pivot shafts of the first fixed pivot group (611) and the second fixed pivot group (711) are respectively in rolling cooperation with the guide grooves of the first guide rail (61) and the second guide rail (71). A limiting structure is provided between the outer edge of the fixed pivot shaft and the inner wall of the guide groove.

6. The apparatus for adjusting the etching uniformity of wafer edges according to claim 4, characterized in that, The pulleys of the first sliding pivot group (612) and the second sliding pivot group (712) form a compound kinematic pair with the guide grooves of the first guide rail (61) and the second guide rail (71), respectively. The rotation axis of the pulley is perpendicular to the extension direction of the first guide rail (61) and the second guide rail (71), and the outer edge of the pulley forms a rolling contact with the bottom surface of the guide groove, and the side wall of the pulley forms a sliding contact with the side wall of the guide groove.

7. The apparatus for adjusting the etching uniformity of wafer edges according to claim 1, characterized in that, A position translation detector (9) is provided on the first fixed pivot group (611), and the position translation detector (9) is used to detect the translation distance of the first sliding pivot group (612).

8. The apparatus for adjusting the etching uniformity of wafer edges according to claim 1, characterized in that, It also includes a support member (8), which includes: an aluminum ring (81) disposed at the bottom of the focusing ring (2) and fixedly connected to the lifting platform (7); and an isolation ring (82) disposed on the circumferential outside of the base (3), the isolation ring (82) being located on the base (3).

9. The apparatus for adjusting the etching uniformity of wafer edges according to claim 5, characterized in that, The guide groove has a first limit position and a second limit position. The first fixed pivot group (611) is located at the first limit position, and the first sliding pivot group (612) can slide to the second limit position. The distance between the first limit position and the second limit position is adjustable.

10. The apparatus for adjusting the etching uniformity of wafer edges according to claim 1, characterized in that, It also includes an isolation sleeve (53), which penetrates the base (3) and is fitted over the outside of the N sets of scissor arm units (5).

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