Silicon wafer gripper

Abstract

The application provides a silicon wafer holder, and relates to the technical field of semiconductor preparation, which comprises a back plate, the front surface of the back plate is provided with a lower clamping piece, an upper clamping piece opposite to the lower clamping piece is slidably connected to the back plate, and the upper clamping piece can move towards or away from the lower clamping piece; the upper clamping piece comprises a base and an arc-shaped elastic sheet, both ends of the arc-shaped elastic sheet are connected with the base respectively, the arc surface of the arc-shaped elastic sheet is curved towards the side where the lower clamping piece is located; the arc-shaped elastic sheet comprises an abutting portion located in the middle portion and connecting portions located at the left and right ends, a transition portion is connected between the connecting portions and the abutting portion, and the transition portion is provided with continuous bending wrinkles.

Description

Technical Field

[0001] This invention relates to the field of semiconductor fabrication technology, and in particular to a silicon wafer holder. Background Technology

[0002] During the formation of thin films on silicon wafers, thicker and heavier silicon wafers are prone to falling off the planetary carrier and breaking due to insufficient clamping force; while thinner silicon wafers are prone to breaking not only during loading and unloading, but also during the formation of thin films due to excessive clamping force. Summary of the Invention

[0003] The purpose of this invention is to provide a silicon wafer holder to alleviate the technical problems of unstable silicon wafer clamping or silicon wafer breakage caused by using the same holder for silicon wafers of different thicknesses in the prior art.

[0004] An embodiment of the present invention provides a silicon wafer holder, comprising: a back plate, the front side of the back plate having a lower clamping member, and an upper clamping member slidably connected to the back plate opposite to the lower clamping member, the upper clamping member being able to move toward or away from the lower clamping member;

[0005] The upper clamping member includes a base and an arc-shaped spring piece, with both ends of the arc-shaped spring piece connected to the base respectively; the arc surface of the arc-shaped spring piece is bent downwards on the side where the clamping member is located; the arc-shaped spring piece includes an abutting part located in the middle part and connecting parts located at the left and right ends, with a transition part connecting the connecting part and the abutting part, and the transition part having continuously bent folds.

[0006] The silicon wafer holder further includes a screw, a nut, and a spring. The screw extends along a first direction, and a guide connecting ring is provided on the back of the back plate. The screw is slidably connected in the guide connecting ring along the first direction. The first direction is parallel to the moving direction of the upper clamping member, and the screw is connected to the upper clamping member.

[0007] A nut is threaded onto the screw; an annular limiting groove is provided on the circumferential outer wall of the nut;

[0008] The first end of the spring has two "L"-shaped connecting structures. Each connecting structure includes a first rod extending along a first direction and a second rod perpendicularly connected to the first rod. The second rods on the two connecting structures extend toward each other in their respective directions. A limiting ring coaxial with the nut is provided between the two second rods. The limiting ring is located in the annular limiting groove. The back of the back plate is also provided with stop bars located on both sides of the connecting structure. The stop bars are used to prevent the connecting structure from rotating with the nut.

[0009] The second end of the spring is fixed to the back plate, and the distance between the upper clamp and the second end of the spring is changed by rotating the nut.

[0010] Furthermore, a connecting post for connecting to the planetary carrier is provided on the back side of the back plate, and the second end of the spring is fixedly connected to the connecting post.

[0011] Furthermore, the spring is a ring spring.

[0012] Furthermore, the back plate has a groove, and the upper clamping member is slidably connected in the groove so that the upper clamping member moves only in the first direction.

[0013] Furthermore, the base includes a vertically connected upper mounting plate and a rear mounting plate, the upper mounting plate being connected to a spring, and the arc-shaped spring piece being connected to the rear mounting plate;

[0014] The rear mounting plate has two receiving groove walls perpendicular to the lower clamping member on one side facing the rear mounting plate, with the two receiving groove walls spaced apart. Each of the two receiving groove walls has a receiving groove opening baffle extending in the direction of the other on the surfaces facing each other, forming a notch between the two receiving groove opening baffles. There is a gap between the receiving groove opening baffles and the rear mounting plate. The connecting part of the arc-shaped spring is fixed in the gap between the receiving groove opening baffles and the rear mounting plate. The top of the arc-shaped spring protrudes from the notch and is higher than the receiving groove opening baffles.

[0015] Furthermore, a cover plate is connected to the base, the cover plate is connected to the rear mounting plate, and the cover plate and the upper mounting plate are respectively located on the front and rear sides of the rear mounting plate;

[0016] The projection of the cover plate onto the upper mounting plate at least covers the projection of the arc-shaped spring sheet onto the upper mounting plate.

[0017] Furthermore, the area of ​​all the wrinkles on the transition section accounts for 50%-90% of the arc surface area of ​​the arc-shaped spring sheet.

[0018] Furthermore, the trajectory of the folds near the edge of the silicon wafer is on the arc surface, and the trajectory of the edges away from the silicon wafer is on a straight line AA' parallel to the tangent at the highest point of the arc surface. The surface of the folds intersects the normal surface BB' at the highest point of the arc surface in the convex direction of the arc surface.

[0019] Furthermore, at least one section of the screw has a rectangular cross-section, which is slidably connected to the guide ring. The inner hole of the guide ring is also rectangular, which is used to prevent the screw from rotating together with the nut.

[0020] Furthermore, the lower clamping member has the same structure as the upper clamping member.

[0021] When using the silicon wafer holder provided in this embodiment of the invention to clamp and fix a silicon wafer, the distance between the upper clamping member and the second end of the spring can be adjusted in advance according to the thickness of the silicon wafer, thereby adjusting the clamping force of the spring. Specifically, when the user rotates the nut clockwise or counterclockwise, the nut moves towards the upper clamping member, reducing the distance between the upper clamping member and the second end of the spring. When clamping the silicon wafer, the spring needs to be stretched for a longer length, resulting in a larger spring force, which is suitable for thicker and heavier silicon wafers. Conversely, when the nut moves away from the upper clamping member, the distance between the upper clamping member and the second end of the spring increases. When clamping silicon wafers of the same radius, the spring needs to be stretched for a shorter length, resulting in a smaller spring force, which is suitable for thinner and lighter silicon wafers. Furthermore, the arc-shaped spring on the upper clamping member can make uniform contact with the sidewall of the silicon wafer. Because, under the action of the spring, the top of the arc-shaped spring abuts against the side wall of the silicon wafer. Continuous folds are set between the abutting part and the connecting part of the arc-shaped spring. The folds in the transition part can reduce the elasticity of the transition part, making it easier for the abutting part to deform towards the connecting part. In other words, after the abutting part abuts against the side wall of the silicon wafer, the abutting part protruding to one side of the silicon wafer can more easily deform outward and become an arc surface protruding away from the silicon wafer. This allows the abutting part to form a surface contact with the side wall of the silicon wafer, reducing the pressure on the side of the silicon wafer from the moving chuck, which helps to prevent the thinner silicon wafer from breaking. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a rear view of a silicon wafer holder provided in an embodiment of the present invention;

[0024] Figure 2 for Figure 1 A magnified view of a portion of position A in the middle;

[0025] Figure 3 This is a side view of a silicon wafer holder provided in an embodiment of the present invention;

[0026] Figure 4 A cross-sectional view of the nut position of the silicon wafer holder provided in an embodiment of the present invention;

[0027] Figure 5A schematic diagram of the upper clamping member of the silicon wafer holder provided in an embodiment of the present invention;

[0028] Figure 6 A schematic diagram of the arc-shaped spring of the silicon wafer holder provided in an embodiment of the present invention;

[0029] Figure 7 A cross-sectional view of the arc surface of the arc-shaped spring of the silicon wafer holder provided in an embodiment of the present invention.

[0030] Icons: 100 - Back plate; 110 - Lower clamping component; 120 - Nut; 121 - Annular limiting groove; 140 - Slide groove;

[0031] 200 - Upper clamping component; 211 - Upper mounting plate; 212 - Rear mounting plate; 213 - Receiving groove wall; 214 - Receiving groove baffle; 230 - Screw;

[0032] 220 – Curved spring; 221 – Abutting part; 222 – Connecting part; 2231 – Wrinkle;

[0033] 300 – Spring; 310 – Connecting structure; 320 – Limiting ring; 330 – Stop bar;

[0034] 400 – Guide connecting ring; 500 – Connecting post. Detailed Implementation

[0035] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] like Figure 1 - Figure 7 As shown, the silicon wafer holder provided in this embodiment of the invention includes: a back plate 100, the front of the back plate 100 having a lower clamping member 110, and an upper clamping member 200 slidably connected to the back plate 100 opposite to the lower clamping member 110. The upper clamping member 200 can move toward or away from the lower clamping member 110. The lower clamping member 110 and the upper clamping member 200 are used to clamp the silicon wafer on opposite sides of the circumferential sidewall, thereby fixing the silicon wafer. In addition to the lower clamping member 110 located below the upper clamping member 200, anti-lateral displacement grippers with the same structure as the lower clamping member 110 can also be provided on the left and right sides of the back plate 100.

[0037] The upper clamping member 200 includes a base and an arc-shaped spring piece 220. The two ends of the arc-shaped spring piece 220 are respectively connected to the base. The arc surface of the arc-shaped spring piece 220 is bent towards the side where the lower clamping member 110 is located, and the middle position of the arc surface is aligned with the middle position of the lower clamping member 110. The material of the arc-shaped spring piece 220 can be metal.

[0038] The arc-shaped spring 220 includes an abutment portion 221 located in the middle and connecting portions 222 located at the left and right ends. A transition portion is connected between the connecting portion 222 and the abutment portion 221. The transition portion has continuous bending folds 2231. The folds 2231 can reduce the elasticity of the transition portion. The abutment portion 221, which is directly connected to the transition portion, is more likely to deform when subjected to the pressure of the silicon wafer, thus making it easier to change from line contact to surface contact.

[0039] The silicon wafer holder also includes a screw 230, a nut 120, and a spring 300. The screw 230 extends along a first direction. A guide connecting ring 400 is provided on the back of the back plate 100. The screw 230 is slidably connected in the guide connecting ring 400 along the first direction. The first direction is parallel to the moving direction of the upper clamping member 200. The screw 230 is connected to the upper clamping member 200. The guide connecting ring 400 plays a limiting and guiding role to prevent the screw 230 from swinging when moving along the first direction.

[0040] A nut 120 is threaded onto the screw 230; an annular limiting groove 121 is provided on the circumferential outer wall of the nut 120; the first end of the spring 300 has two "L"-shaped connecting structures 310, each connecting structure 310 including a first rod extending along a first direction and a second rod perpendicularly connected to the first rod, the second rods on the two connecting structures 310 extending towards each other in their respective directions, a limiting ring 320 coaxial with the nut 120 is provided between the two second rods, the diameter of the limiting ring 320 is smaller than the outer diameter of the nut 120, and the limiting ring 320 is located within the annular limiting groove 121; the back of the back plate 100 is also provided with stop bars 330 located on both sides of the connecting structure 310, the plane formed by the two stop bars 330 is perpendicular to the plane formed by the two first rods, and the stop bars 330 are used to prevent the connecting structure 310 from rotating with the nut 120; the second end of the spring 300 is fixed to the back plate 100. When the nut 120 rotates, the limiting ring 320 does not rotate with the nut 120 to prevent the spring 300 from being torsional deformed. However, when the nut 120 moves relative to the screw 230 in the first direction, the limiting ring 320 can push the nut 120 and the screw 230 to move together relative to the second end of the spring 300.

[0041] When using the silicon wafer holder provided in this embodiment of the invention to clamp and fix a silicon wafer, the distance between the upper clamping member 200 and the second end of the spring 300 can be adjusted in advance according to the thickness of the silicon wafer, thereby adjusting the clamping force of the spring 300. Specifically, when the user rotates the nut 120 clockwise or counterclockwise, the nut 120 moves towards the upper clamping member 200, reducing the distance between the upper clamping member 200 and the second end of the spring 300. When clamping the silicon wafer, the spring 300 needs to be stretched for a longer length, and the spring force of the spring 300 is greater, which is suitable for thicker and heavier silicon wafers. Conversely, when the nut 120 moves away from the upper clamping member 200, the distance between the upper clamping member 200 and the second end of the spring 300 increases. When clamping silicon wafers of the same radius, the spring 300 needs to be stretched for a shorter length, and the spring force of the spring 300 is smaller, which is suitable for thinner and lighter silicon wafers. Furthermore, the arc-shaped spring piece 220 on the upper clamping member 200 can make uniform contact with the sidewall of the silicon wafer. Because, under the action of the spring 300, the top of the arc-shaped spring 220 abuts against the side wall of the silicon wafer. A continuous pleat 2231 is provided between the abutting part 221 and the connecting part 222 of the arc-shaped spring 220. The pleat 2231 in the transition part can reduce the elasticity of the transition part, so that the abutting part 221 can deform more easily in the direction of the connecting part 222. That is to say, after the abutting part 221 abuts against the side wall of the silicon wafer, the abutting part 221 protruding to one side of the silicon wafer can deform more easily to the outside, becoming an arc surface protruding away from the silicon wafer. This makes the abutting part 221 form a surface contact with the side wall of the silicon wafer, reducing the pressure of the moving chuck on the side of the silicon wafer, which helps to prevent the thinner silicon wafer from breaking.

[0042] The back plate 100 has a connecting post 500 on its back side that connects to the planetary carrier. Multiple wafer holders are fixed on one planetary carrier. The second end of the spring 300 is fixedly connected to the connecting post 500. The spring 300 can be a ring spring 300.

[0043] The back plate 100 has a groove 140, and the upper clamping member 200 is slidably connected in the groove 140 so that the upper clamping member 200 moves only in the first direction, avoiding deviation of the upper clamping member 200 in the left and right directions when it moves in the first direction, which would affect the force applied by the arc-shaped spring 220 to the sidewall of the silicon wafer.

[0044] Furthermore, the base includes an upper mounting plate 211 and a rear mounting plate 212 that are vertically connected. The upper mounting plate 211 is connected to the spring 300, and the arc-shaped spring piece 220 is connected to the rear mounting plate 212.

[0045] The base includes an upper mounting plate 211 and a rear mounting plate 212 connected vertically. The upper mounting plate 211 is located on the rear side of the back plate 100. The upper mounting plate 211 is fixedly connected to the spring 300. The arc-shaped spring piece 220 is connected to the rear mounting plate 212, and the arc surface of the arc-shaped spring piece 220 faces downward. The rear mounting plate 212 has a receiving groove wall 213 perpendicular to the lower clamping member 110 on one side. There are two receiving groove walls 213, which are spaced apart. Each of the two receiving groove walls 213 has a receiving groove baffle 214 extending in the direction of each other on the surfaces facing each other. A notch is formed between the two receiving groove baffles 214. There is a gap between the receiving groove baffles 214 and the rear mounting plate 212. The connecting part 222 of the arc-shaped spring piece 220 is fixed in the gap between the receiving groove baffles 214 and the rear mounting plate 212. The top of the arc-shaped spring piece 220 protrudes from the notch and is higher than the receiving groove baffles 214, so that the top of the arc-shaped spring piece 220 can abut against the sidewall of the silicon wafer.

[0046] A cover plate is connected to the base, and the cover plate is connected to the rear mounting plate 212. The cover plate and the upper mounting plate 211 are located on the front and rear sides of the rear mounting plate 212, respectively. The projection of the cover plate on the upper mounting plate 211 at least covers the projection of the arc-shaped spring piece 220 on the upper mounting plate 211. In addition to confining the arc-shaped spring piece 220 between the receiving groove wall 213 and the receiving groove baffle 214, the cover plate also serves to restrict the silicon wafer. The lower edge of the cover plate extends downward to below the top of the arc-shaped spring piece 220. After the silicon wafer abuts against the arc-shaped spring piece 220, the cover plate can prevent the silicon wafer from tilting forward, thereby protecting the silicon wafer.

[0047] The area of ​​all the wrinkles 2231 on the transition portion accounts for 50%-90% of the arc surface area of ​​the arc-shaped spring piece 220. The proportion of wrinkles 2231 affects the ease with which the abutment portion 221 deforms. Setting the proportion of the area of ​​wrinkles 2231 between 50% and 90% ensures that the abutment portion 221 can deform upwards relatively easily, while also ensuring that the abutment portion 221 does not fail to return to its original shape after the silicon wafer is removed.

[0048] The trajectory of the fold 2231 near the edge of the silicon wafer is on the arc surface, and the trajectory of the edge away from the silicon wafer is on a straight line AA' parallel to the tangent at the highest point of the arc surface. The surface of the fold 2231 intersects the normal surface BB' at the highest point of the arc surface in the convex direction of the arc surface.

[0049] When the silicon wafer comes into contact with the contact portion 221, it is subjected to pressure from the outside in. The folds 2231 on both sides of the contact portion 221 will gradually contract. The surface of the folds 2231 intersects the normal surface BB' of the highest point of the arc surface in the convex direction of the arc surface, thereby facilitating the inward concavity of the contact portion 221. The arc surface convex towards the silicon wafer becomes an arc surface convex away from the silicon wafer, thereby forming a surface contact between the contact portion 221 and the sidewall of the silicon wafer, reducing the pressure exerted by the upper clamping member 200 on the side of the silicon wafer, which helps to prevent the thinner silicon wafer from breaking. Furthermore, by setting the position of the two sets of opposite edges of the folds 2231, the folds 2231 can be compressed from the contact portion 221 towards the connecting portion 222 along the arc direction of the arc surface itself, thereby better restoring the folds 2231 to their original shape and avoiding the problem of not being able to recover after compression.

[0050] At least one section of the screw 230 has a rectangular cross-section, which is slidably connected to the guide ring 400. The inner hole of the guide ring 400 is also rectangular, preventing the screw 230 from rotating with the nut 120 when the nut 120 is manually rotated.

[0051] Furthermore, the structure of the lower clamping member 110 can be the same as that of the upper clamping member 200, so that the arc-shaped spring piece 220 on the lower clamping member 110 can make surface contact with the silicon wafer and reduce pressure.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A silicon wafer holder, characterized in that, include: A back plate (100) has a lower clamping member (110) on its front side. An upper clamping member (200) is slidably connected to the back plate (100) opposite to the lower clamping member (110). The upper clamping member (200) can move toward or away from the lower clamping member (110). The upper clamping member (200) includes a base and an arc-shaped spring piece (220), with both ends of the arc-shaped spring piece (220) connected to the base respectively; the arc surface of the arc-shaped spring piece (220) is bent towards the side where the lower clamping member (110) is located; the arc-shaped spring piece (220) includes an abutment part (221) located in the middle part and a connecting part (222) located at the left and right ends, and a transition part is connected between the connecting part (222) and the abutment part (221), and the transition part has continuously bent folds (2231); The silicon wafer holder further includes a screw (230), a nut (120), and a spring (300). The screw (230) extends along a first direction. A guide connecting ring (400) is provided on the back side of the back plate (100). The screw (230) is slidably connected in the guide connecting ring (400) along the first direction. The first direction is parallel to the moving direction of the upper clamping member (200). The screw (230) is connected to the upper clamping member (200). A nut (120) is threaded onto the screw (230); an annular limiting groove (121) is provided on the circumferential outer wall of the nut (120); The first end of the spring (300) has two "L"-shaped connecting structures (310). Each connecting structure (310) includes a first rod extending along a first direction and a second rod perpendicularly connected to the first rod. The second rods on the two connecting structures (310) extend toward each other in their respective directions. A limiting ring (320) coaxial with the nut (120) is provided between the two second rods. The limiting ring (320) is located in the annular limiting groove (121). The back of the back plate (100) is also provided with stop bars (330) located on both sides of the connecting structure (310). The stop bars (330) are used to prevent the connecting structure (310) from rotating with the nut (120). The second end of the spring (300) is fixed to the back plate (100), and the distance between the upper clamp (200) and the second end of the spring (300) is changed by rotating the nut (120).

2. The silicon wafer holder according to claim 1, characterized in that, The back plate (100) is provided with a connecting post (500) that is connected to the planetary carrier, and the second end of the spring (300) is fixedly connected to the connecting post (500).

3. The silicon wafer holder according to claim 1, characterized in that, The spring (300) is a ring spring (300).

4. The silicon wafer holder according to claim 1, characterized in that, The back plate (100) has a groove (140), and the upper clamping member (200) is slidably connected in the groove (140) so that the upper clamping member (200) moves only in a first direction.

5. The silicon wafer holder according to claim 1, characterized in that, The base includes a vertically connected upper mounting plate (211) and a rear mounting plate (212), the upper mounting plate (211) is connected to a spring (300), and the arc-shaped spring piece (220) is connected to the rear mounting plate (212); The rear mounting plate (212) has a receiving groove wall (213) perpendicular to the lower clamping member (110) on one side. There are two receiving groove walls (213), which are spaced apart. Each of the two receiving groove walls (213) has a receiving groove baffle (214) extending in the direction of each other on the surfaces facing each other. A notch is formed between the two receiving groove baffles (214). There is a gap between the receiving groove baffles (214) and the rear mounting plate (212). The connecting part (222) of the arc-shaped spring piece (220) is fixed in the gap between the receiving groove baffle (214) and the rear mounting plate (212). The top of the arc-shaped spring piece (220) protrudes from the notch and is higher than the receiving groove baffle (214).

6. The silicon wafer holder according to claim 5, characterized in that, A cover plate is connected to the base, the cover plate is connected to the rear mounting plate (212), and the cover plate and the upper mounting plate (211) are located on the front and rear sides of the rear mounting plate (212), respectively. The projection of the cover plate onto the upper mounting plate (211) at least covers the projection of the arc-shaped spring sheet (220) onto the upper mounting plate (211).

7. The silicon wafer holder according to claim 1, characterized in that, The area of ​​all the folds (2231) on the transition section accounts for 50%-90% of the arc surface area of ​​the arc-shaped spring (220).

8. The silicon wafer holder according to claim 1, characterized in that, The trajectory of the fold (2231) near the edge of the silicon wafer is on the arc surface, and the trajectory of the edge away from the silicon wafer is on a straight line AA' parallel to the tangent at the highest point of the arc surface. The surface of the fold (2231) intersects the normal surface BB' at the highest point of the arc surface in the convex direction of the arc surface.

9. The silicon wafer holder according to claim 1, characterized in that, At least one section of the screw (230) has a rectangular cross-section, which is slidably connected to the guide connecting ring (400). The inner hole of the guide connecting ring (400) is also rectangular, which is used to prevent the screw (230) from rotating together with the nut (120).

10. The silicon wafer holder according to claim 1, characterized in that, The lower clamping member (110) has the same structure as the upper clamping member (200).

Images