Magnetic clamping type wafer double-side cleaning rotating mechanism

Abstract

The application relates to a magnetic clamping type wafer double-side cleaning rotary mechanism which is used for double-side cleaning of a wafer and comprises an upper cavity, a lower cavity, a chuck, a chuck shaft, a gas-liquid separator and a liquid discharge pump. The top of the chuck shaft is provided with a back spray cover plate, and the center of the back spray cover plate is provided with a spray hole. A magnetic clamping mechanism is arranged on the chuck, and a plurality of waste discharge pipes are arranged at the lower part of the lower cavity. The magnetic clamping type wafer double-side cleaning rotary mechanism clamps the wafer through the magnetic clamping mechanism. The wafer outer circle clamping mode does not cause damage to the wafer (compared with damage to the lower surface of the wafer caused by a vacuum suction cup structure). The clamping effect is good. The clamped wafer can be double-side cleaned at the same time. The cleaning liquids used on the upper and lower surfaces of the wafer can be different and do not affect each other, so that the cleaning range of the wafer is significantly expanded, and the adaptability is high.

Description

Technical Field

[0001] This invention relates to a magnetic clamping type wafer double-sided cleaning rotation mechanism, belonging to the field of wafer cleaning technology. Background Technology

[0002] There are many steps in wafer fabrication, but the positioning of the wafer on the chuck is a problem that must be carefully considered in each step. Some steps rely on vacuum chucks for positioning, while others rely on the outer diameter of the wafer for positioning. Some outer diameter positioning requires clamping, while others do not. Wafer outer diameter positioning and clamping seem like a simple action, but because clamping the chuck requires high-speed rotation, compressed air or electrical connections are difficult, and the dynamic balance of the chuck is very important, the device that drives the clamping cannot be installed on the chuck. This makes outer diameter clamping much more difficult than vacuum chuck clamping.

[0003] With the increasing demands for single-wafer cleaning processes and the need to improve production efficiency, single-sided cleaning using chuck positioning can no longer meet the requirements of both processes and production efficiency. The market requires a process that clamps the outer circumference of the wafer to achieve double-sided cleaning, which avoids damage to the wafer when the chuck is adsorbing it and greatly improves production efficiency. Therefore, improvements have been made to the existing chuck positioning and clamping technology.

[0004] Based on this, the present invention is proposed. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing a magnetic clamping wafer double-sided cleaning and rotating mechanism, the specific technical solution of which is as follows:

[0006] A magnetic clamping wafer double-sided cleaning rotary mechanism is disclosed for double-sided cleaning of wafers. It includes an upper cavity, a lower cavity adapted to the upper cavity, a chuck coaxially arranged with the upper cavity, a chuck mandrel coaxially connected to the chuck, a gas-liquid separator, and a drain pump. The chuck mandrel has a hollow structure, and a back spray cover is provided on the top of the chuck mandrel. A spray hole is provided in the center of the back spray cover. The chuck is equipped with a magnetic clamping mechanism for clamping the wafer. Multiple waste discharge pipes are provided at the lower part of the lower cavity. The inner cavity of each waste discharge pipe is connected to the inner cavity of the lower cavity. Each waste discharge pipe is connected to the input end of the drain pump. The output end of the drain pump is connected to the inlet end of the gas-liquid separator. The gas-liquid separator is equipped with an exhaust pipe and a drain pipe.

[0007] In a further improvement, the chuck spindle is coaxially provided with an inlet pipe, a transition sleeve is connected between the back spray cover plate and the upper part of the chuck spindle, a bearing is connected between the inlet pipe and the chuck spindle, a bearing washer is provided below the bearing, an elastic retaining ring for supporting the bearing is provided below the bearing washer, a connecting sleeve for connecting the upper end of the inlet pipe is installed between the bearing and the transition sleeve, and the inner cavity of the inlet pipe communicates with the spray hole.

[0008] In a further improvement, the magnetic clamping mechanism includes at least one set of support units for supporting the wafer, at least one set of left clamping units for clamping the wafer, and at least one set of right clamping units for clamping the wafer. The support units, left clamping units, and right clamping units are all located on the edge of the chuck. Each support unit includes two sets of support components, which are symmetrically arranged about the axis of the chuck. Both the left and right clamping units include positioning components. The left clamping unit further includes a left clamping component, and the right clamping unit further includes a right clamping component. The positioning component in the left clamping unit is symmetrically arranged with the left clamping component about the axis of the chuck, and the positioning component in the right clamping unit is symmetrically arranged with the right clamping component about the axis of the chuck. A magnetic disk assembly for driving the left and right clamping components to perform clamping actions is located below the chuck, and an movable opening is provided at the upper end of the upper cavity.

[0009] The positioning component includes a cylindrical second bottom post fixedly installed on the edge of the chuck. The upper end of the second bottom post is provided with a first cone portion, and the top of the first cone portion is provided with a cylindrical second protrusion. The axis of the second protrusion is eccentrically arranged with the axis of the second bottom post, and the axis of the first cone portion is coaxial with the axis of the second protrusion.

[0010] The left and right clamping assemblies have the same structure. Each assembly includes a support base fixedly mounted on the edge of the chuck, a rotating column rotatably connected to the support base, a magnetic rotating shaft for driving the rotating column to rotate, and a first screw for connecting the magnetic rotating shaft and the rotating column. The support base is sleeved on the outside of the magnetic rotating shaft, and a self-aligning ball bearing is installed between the upper part of the magnetic rotating shaft and the support base. The upper part of the rotating column is provided with a second cone, and a cylindrical third protrusion is coaxially provided on the top of the second cone. The axis of the third protrusion is eccentrically arranged with the axis of the rotating column. A cuboid permanent magnet is provided at the lower end of the magnetic rotating shaft. A second screw is provided on one side of the head end of the permanent magnet, and a third screw is provided on the other side of the tail end of the permanent magnet. A magnet cover is sleeved on the outside of the permanent magnet. The magnet cover is fixedly connected to the magnetic rotating shaft by the second and third screws. The permanent magnet is located below the support base.

[0011] The support assembly includes a first bottom post fixedly installed on the side of the chuck, a cylindrical column connected to the upper end of the first bottom post, and a cylindrical first protrusion coaxially connected to the upper end of the column, the first protrusion being eccentrically positioned with respect to the first bottom post.

[0012] In a further improvement, the lower part of the support base is provided with a limiting groove for limiting the movement trajectory of the upper end of the third screw. The upper end of the third screw extends out of the lower part of the magnetic rotation shaft and the upper end of the third screw is located in the limiting groove. The limiting groove has an arc-shaped structure and the central angle corresponding to the limiting groove is 90°.

[0013] In a further improvement, the magnetic disk assembly includes a circular magnetic disk base with an annular groove along its edge. Multiple drive magnets for driving the permanent magnet to rotate are disposed within the annular groove. A magnetic disk cover plate for covering all the drive magnets is also fixedly installed on the magnetic disk base. A first through hole for the lower part of the chuck spindle to pass through is provided in the center of the magnetic disk base. An annular support groove is provided at the bottom of the lower cavity. The magnetic disk base is fixedly connected to the top of the support groove.

[0014] In a further improvement, the eccentricity between the axis of the third protruding post and the axis of the rotating post is 2.6 mm, the eccentricity between the axis of the second protruding post and the axis of the second bottom post is 1.7 mm, and the eccentricity between the first protruding post and the first bottom post is 2.2 mm.

[0015] A further improvement is that the cone angle of the first cone is not equal to the cone angle of the second cone.

[0016] In a further improvement, the upper surface of the back spray cover is provided with raised textures, the raised textures are located on one side of the spray hole, and a through-hole groove is provided on the other side of the spray hole. The thickness of the raised textures is 1.1 mm, and the shape of the raised textures is the same as the shape of the through-hole groove. The raised textures include arc-shaped protrusions, and each end of the arc-shaped protrusion is provided with a long strip-shaped extension, the included angle between the two extensions is 137°, and a straight section one is provided on the side of the arc-shaped protrusion near the spray hole. The through-hole groove includes an arc-shaped hole, and each end of the arc-shaped hole is provided with a long strip-shaped extension hole, the included angle between the two extension holes is 137°, and a straight section two is provided on the side of the arc-shaped hole near the spray hole. The vertical distance between the surface of the straight section one and the center of the spray hole is m, and the vertical distance between the surface of the straight section two and the center of the spray hole is n, where 1.05 ≤ m / n ≤ 1.2.

[0017] A further improvement is made to the rotation speed of the back spray cover, which is 600–2000 r / min.

[0018] A further improvement is that the rotational speed of the back spray cover is greater than 3000 r / min.

[0019] The beneficial effects of this invention are:

[0020] The magnetic clamping wafer double-sided cleaning rotary mechanism clamps the wafer using a magnetic clamping mechanism. This method of clamping the outer circumference of the wafer does not damage the wafer (compared to the damage to the lower surface of the wafer caused by vacuum suction cup adsorption), and the clamping effect is good. The clamped wafer can be cleaned on both sides at the same time, and the cleaning solutions used on the upper and lower surfaces of the wafer can be different and do not affect each other, thereby significantly expanding the cleaning range of the wafer and making it highly adaptable. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the magnetic clamping wafer double-sided cleaning and rotating mechanism described in this invention.

[0022] Figure 2 This is a schematic diagram of the magnetic clamping wafer double-sided cleaning rotating mechanism of the present invention during cleaning.

[0023] Figure 3 This is a schematic diagram of the magnetic clamping wafer double-sided cleaning rotating mechanism described in this invention after cleaning.

[0024] Figure 4 This is a schematic diagram showing the distribution of the support unit, left clamping unit, and right clamping unit described in this invention;

[0025] Figure 5 This is a schematic diagram of the magnetic disk assembly described in this invention;

[0026] Figure 6 for Figure 5 BB view;

[0027] Figure 7 This is a schematic diagram showing the distribution of the support base, permanent magnet, second screw, and third screw described in this invention;

[0028] Figure 8 This is a schematic diagram of the structure of the left clamping assembly or the right clamping assembly described in this invention;

[0029] Figure 9 This is a schematic diagram of the structure of the support base described in this invention;

[0030] Figure 10 This is a schematic diagram of the positioning component described in this invention;

[0031] Figure 11 This is a schematic diagram of the structure of the support component described in this invention.

[0032] Figure 12 This is a schematic diagram showing the coaxial rotatable connection between the liquid inlet pipe and the chuck spindle of the present invention;

[0033] Figure 13 This is a schematic diagram of the structure of the back spray cover plate described in this invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0035] In the description of this invention, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention 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 invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] Example 1

[0038] like Figures 1-4 As shown, the magnetic clamping wafer double-sided cleaning rotating mechanism is used to perform double-sided cleaning on wafer 1. The magnetic clamping wafer double-sided cleaning rotary mechanism includes an upper cavity 10, a lower cavity 11 adapted to the upper cavity 10, a chuck 13 coaxially arranged with the upper cavity 10, a chuck mandrel 12 coaxially connected with the chuck 13, a gas-liquid separator 2, and a drain pump 4. The chuck mandrel 12 has a hollow structure. The top of the chuck mandrel 13 is provided with a back spray cover plate 40, and the center of the back spray cover plate 40 is provided with a spray hole 41. The chuck 13 is provided with a magnetic clamping mechanism for clamping the wafer 1. The lower part of the lower cavity 11 is provided with multiple waste discharge pipes 15. The inner cavity of the waste discharge pipes 15 is connected to the inner cavity of the lower cavity 11. The waste discharge pipes 15 are all connected to the input end of the drain pump 4. The output end of the drain pump 4 is connected to the liquid inlet end of the gas-liquid separator 2. The gas-liquid separator 2 is provided with an exhaust pipe 3 and a drain pipe 5.

[0039] The magnetic clamping mechanism includes at least one set of support units for supporting wafer 1, at least one set of left clamping units for clamping wafer 1, and at least one set of right clamping units for clamping wafer 1. The support units, left clamping units, and right clamping units are all located on the edge of the chuck 13. Each support unit includes two sets of support components 50, which are symmetrically arranged about the axis of the chuck 13. Both the left and right clamping units include positioning components 30, and the left clamping unit also includes a left clamping component. The clamping assembly 20, the right clamping unit further includes a right clamping assembly 20a, the positioning assembly 30 in the left clamping unit and the left clamping assembly 20 are symmetrically arranged about the axis of the chuck 13, the positioning assembly 30 in the right clamping unit and the right clamping assembly 20a are symmetrically arranged about the axis of the chuck 13; a magnetic disk assembly 60 for driving the left clamping assembly 20 and the right clamping assembly 20a to perform clamping actions is provided below the chuck 13, and an movable port 101 is provided at the upper end of the upper cavity 10.

[0040] The chuck spindle 12 is driven by a motor via gears, enabling the chuck 13 to rotate at high speed. The lower cavity 11 is mounted on a lifting cylinder, which can move the lower cavity 11 and the magnetic disk assembly 60 up and down. The up-and-down movement of the lifting cylinder causes the lower cavity, magnetic disk assembly, and upper cavity to move up and down. The chuck, wafer, and chuck spindle 12, driven by the motor, only rotate and cannot move up and down; simply put, the movable port 101 moves up and down. The magnetic disk assembly and the upper cavity are both mounted on the lower cavity, such as... Figure 3 As shown. During cleaning, the lower cavity 11 and the magnetic disk assembly 60 move upward, thereby causing the upper part of the support unit, the upper part of the left clamping unit, the upper part of the right clamping unit, and the wafer 1 to return to the interior of the upper cavity 10, as shown. Figure 2 As shown, the upper surface of wafer 1 is sprayed and cleaned; simultaneously, liquid can be introduced through the hollow structure of the chuck mandrel 12, and finally sprayed from the spray hole in the center of the back spray cover 40 to clean the lower surface of wafer 1; the chuck mandrel 12 has a liquid channel inside to achieve cleaning of the lower surface of the wafer. The upper cavity 10 is used to prevent liquid from splashing out during cleaning. The lower cavity 11 can discharge gas, liquid, etc. generated during cleaning, and has three waste discharge pipes 15.

[0041] The magnetic clamping wafer double-sided cleaning rotation mechanism can achieve double-sided cleaning of wafers, which greatly improves production efficiency. In addition, when cleaning the upper surface of wafer 1, its lower surface is also cleaned with pure water, nitrogen or other cleaning fluid. Under the pressure of pure water, nitrogen or other cleaning fluid on the lower surface, it can also prevent the cleaning fluid on the upper surface of wafer 1 from contaminating the lower surface.

[0042] Start the drain pump 4 to smoothly discharge the liquid generated during the cleaning of the lower cavity 11 into the gas-liquid separator 2 outside the lower cavity 11. Gas-liquid separation is carried out in the gas-liquid separator 2. The waste liquid is finally discharged from the drain pipe 5 to the designated area for centralized treatment, and the waste gas is discharged from the exhaust pipe 3 to the designated equipment for purification treatment.

[0043] Example 2

[0044] In Example 1, as Figure 12 As shown, the chuck spindle 12 is coaxially provided with an inlet pipe 76. A transition sleeve 71 is connected between the back spray cover plate 40 and the upper part of the chuck spindle 12. A bearing 73 is connected between the inlet pipe 76 and the chuck spindle 12. A bearing washer 74 is provided below the bearing 73. An elastic retaining ring 75 for supporting the bearing 73 is provided below the bearing washer 74. A connecting sleeve 72 for connecting the upper end of the inlet pipe 76 is installed between the bearing 73 and the transition sleeve 71. The inner cavity of the inlet pipe 76 is connected to the spray hole 41.

[0045] The inlet pipe 76 is coaxially rotatably connected to the chuck spindle 12 via a bearing 73. Thus, when the chuck spindle 12 rotates, the inlet pipe 76 remains stationary. In addition, the cleaning fluid or gas can be sprayed upward through the nozzle 41 via the inlet pipe 76.

[0046] Example 3

[0047] In Example 1, as Figure 2 , 3 As shown in Figure 10, the positioning component 30 includes a cylindrical second bottom post 31 fixedly installed on the side of the chuck 13. The upper end of the second bottom post 31 is provided with a first cone portion 32. The top of the first cone portion 32 is provided with a cylindrical second protrusion 33. The axis of the second protrusion 33 is eccentrically arranged with the axis of the second bottom post 31. The axis of the first cone portion 32 is coaxial with the axis of the second protrusion 33. The diameter of the second protrusion 33 is smaller than the diameter of the second bottom post 31.

[0048] The two positioning components 30 are placed close together on the same side of the axis connecting the two support components 50. This allows for a more stable clamping of the wafer 1. The conical surface of the first cone 32 serves two purposes: first, to avoid damage caused by excessive contact with the lower surface of the wafer; and second, to prevent the cleaning fluid from cleaning the edges of the lower surface of the wafer. The second protrusion 33 positions the outer circle of the wafer. After the outer circle of the wafer is pressed against the cylindrical surfaces of the two second protrusions 33, the axis of the wafer is coaxial with the axis of the chuck 13.

[0049] like Figure 2 , 3As shown in Figures 7 and 8, the left clamping assembly 20 and the right clamping assembly 20a have the same structure. Both the left clamping assembly 20 and the right clamping assembly 20a include a support base 25 fixedly installed on the side of the chuck 13, a rotating column 21 rotatably connected to the support base 25, a magnetic rotating shaft 27 for driving the rotating column 21 to rotate, and a first screw 26 for connecting the magnetic rotating shaft 27 and the rotating column 21. The support base 25 is sleeved on the outside of the magnetic rotating shaft 27, and a self-aligning ball bearing 24 is installed between the upper part of the magnetic rotating shaft 27 and the support base 25. The upper part of the rotating column 21 is provided with a second cone 23. A cylindrical third protrusion 22 is coaxially arranged on the top of the second cone 23, and the axis of the third protrusion 22 is eccentrically arranged with respect to the axis of the rotating column 21; a cuboid permanent magnet 28 is arranged at the lower end of the magnetic rotating shaft 27, a second screw 211 is arranged on one side of the head end of the permanent magnet 28, and a third screw 210 is arranged on the other side of the tail end of the permanent magnet 28; a magnet cover 29 is fitted over the permanent magnet 28, and the magnet cover 29 is fixedly connected to the magnetic rotating shaft 27 by the second screw 211 and the third screw 210; the permanent magnet 28 is arranged below the support base 25.

[0050] The pushing force that brings the wafer close to the two positioning components 30 is achieved by the left clamping component 20 and the right clamping component 20a, which are directly opposite the two positioning components 30. The left clamping component 20 and the right clamping component 20a are collectively referred to as the two clamping components. The rotating column 21 can rotate around its own axis by a certain angle (such as 90°). The third protrusion 22 is eccentric relative to the rotating column 21. Therefore, when the rotating column 21 rotates, the third protrusion 22 can push the wafer to move towards the axis of the chuck 13. During clamping, the rotating columns 21 of the two clamping components rotate simultaneously. The rotating column 21 of the left clamping component 20 rotates clockwise, and the rotating column 21 of the right clamping component 20a rotates counterclockwise. This pushes the wafer towards the center of the chuck 13. When the outer circle of the wafer is close to the cylindrical surface of the second protrusion 33 on the positioning component 30, the rotation stops, but there is always a pushing force acting on the wafer, thereby achieving the positioning and clamping of the wafer.

[0051] When the magnetic rotating shaft 27 rotates synchronously under the rotation of the permanent magnet 28, the rotating column 21 will also rotate accordingly due to the fixation of the first screw 26.

[0052] It should be noted that a conical surface cannot be set for the support component 50, otherwise the initial horizontal state of the wafer during placement cannot be guaranteed.

[0053] like Figure 2 , 3As shown in Figure 11, the support assembly 50 includes a first bottom post 51 fixedly installed on the side of the chuck 13. The upper end of the first bottom post 51 is connected to a cylindrical column 53. The upper end of the column 53 is coaxially connected to a cylindrical first protruding post 52. The first protruding post 52 and the first bottom post 51 are eccentrically arranged.

[0054] Since the positioning component 30, the left clamping component 20, and the right clamping component 20a all adopt an eccentric design, if the first protrusion 52 and the first bottom post 51 are coaxially arranged, it will lead to a defect such as the inability to place the wafer.

[0055] The two pillars 53 only serve to support the lower surface of the wafer, while the wafer is supported by the upper surface of the pillars 53. The diameter of the first protrusion 52 is smaller than the diameter of the pillar 53, and the first protrusion 52 serves to restrict the outward movement of the outer circle of the wafer. The two support components 50 are distributed at 180 degrees relative to the axis of the chuck 13.

[0056] Example 4

[0057] In Example 3, as Figure 2 , 3 As shown in Figures 5 and 6, the magnetic disk assembly 60 includes a circular magnetic disk base 61. The edge of the magnetic disk base 61 is provided with an annular groove. Multiple drive magnets 62 for driving the permanent magnet 28 to rotate are arranged in the annular groove. A magnetic disk cover plate 63 for covering all the drive magnets 62 is also fixedly installed on the magnetic disk base 61. A first through hole 611 for the lower part of the chuck spindle 12 to pass through is provided in the center of the magnetic disk base 61. An annular support groove 102 is provided at the bottom of the lower cavity 11. The magnetic disk base 61 is fixedly connected to the top of the support groove 102.

[0058] The core challenge of this invention lies in achieving the air-to-air rotation of the rotating column 21. At the bottom of the left clamping assembly 20 and the right clamping assembly 20a is a magnetic rotating shaft 27, coaxially connected to the rotating column 21. A magnet receiving groove is located at the bottom of the magnetic rotating shaft 27, containing a permanent magnet 28 composed of three square magnets. The permanent magnet 28 has N and S poles. Applying a driving magnetic force to these two poles causes the permanent magnet 28 to rotate around the axis of the magnetic rotating shaft 27, thereby rotating the rotating column 21. Switching the magnetic poles of the driving magnet 62 causes the rotating column 21 to rotate in the opposite direction, thus achieving the clamping and releasing of the wafer.

[0059] The working principle of the magnetic clamping chuck is as follows:

[0060] The chuck 13 is mounted on the chuck spindle 12, which is mounted on a motor. The motor drives the chuck spindle 12 and the chuck 13 to rotate at high speed. The motor is fixed in place on the equipment frame. The lower cavity 11 is mounted on a lifting cylinder and can move up and down along the axis of the chuck 13. The lower cavity 11 is equipped with a magnetic disk assembly 60, which is equipped with a drive magnet 62. The outer side of the drive magnet 62 (when mounted on the magnetic disk base 61, the direction away from the axis of the magnetic disk base 61 is the outer side, and the direction closer to the axis is the inner side) is a magnetic pole, and the inner side is a magnetic pole.

[0061] The driving magnet 62 is a permanent magnet. As the magnetic disk assembly 60 moves up and down, the N and S poles of the driving magnet 62 and the center line of the permanent magnet 28 are automatically adjusted and switched, thereby automatically applying the corresponding magnetic force (repulsion or attraction) to the permanent magnet 28. Therefore, when the magnetic disk assembly 60 moves up and down, by applying repulsive or attractive magnetic forces to the permanent magnet 28, the permanent magnet 28 is made to rotate clockwise or counterclockwise around the magnetic rotation axis 27, thereby realizing the clamping and releasing action of the wafer.

[0062] The magnetic disk assembly 60 is located inside the permanent magnets 28 of the left clamping assembly 20 and the right clamping assembly 20a. The outer magnetic poles of the driving magnet 62 can generate an attractive force or a pushing force on the magnetic poles of the permanent magnet 28, causing the rotating column 21 to rotate.

[0063] Since the drive magnets 62 are arranged in a ring, the drive magnets 62 and permanent magnets 28 will generate magnetic force when the chuck 13 is rotated to any position. Through magnetic drive, the chuck 13 can perform clamping and releasing actions on the wafer without installing a drive device.

[0064] Because the driving magnet 62 has a strong magnetic force (neodymium iron boron magnets can be used) and a small moving distance, even when the lower cavity 11 moves up and down, and the magnetic disk assembly 60 moves up and down as well, the driving magnet 62 will not lose its magnetic force on the permanent magnet 28. Moreover, when clamping, the driving magnet 62 is exactly at the position closest to the permanent magnet 28, ensuring that the clamping force on the high-speed rotating wafer reaches the maximum and ensuring the clamping effect.

[0065] This structure that clamps the outer circumference of the wafer also avoids damage to the lower surface of the wafer during vacuum suction, enabling higher precision cleaning processes for wafers with high requirements on both sides.

[0066] Example 5

[0067] like Figure 8 , 9As shown, the lower part of the support base 25 is also provided with a limiting groove 251 for limiting the movement trajectory of the upper end of the third screw 210. The upper end of the third screw 210 extends out of the lower part of the magnetic rotation shaft 27 and the upper end of the third screw 210 is located in the limiting groove 251. The limiting groove 251 has an arc-shaped structure and the central angle corresponding to the limiting groove 251 is 90°.

[0068] The eccentricity between the axis of the third protruding post and the axis of the rotating post is x, x = 2.6 mm; the eccentricity between the axis of the second protruding post and the axis of the second bottom post is y, y = 1.7 mm; and the eccentricity between the first protruding post 52 and the first bottom post 51 is z, z = 2.2 mm.

[0069] If x = y = z = 2.6 mm, then no matter how the magnetic rotation shaft 27 is rotated, the wafer cannot be completely clamped; similarly, if x = y = z = 1.7 mm, then no matter how the magnetic rotation shaft 27 is rotated, the wafer cannot be completely clamped; if x = y = z = 2.2 mm, then no matter how the magnetic rotation shaft 27 is rotated, the wafer cannot be completely clamped.

[0070] When (zy) > (xz), especially when (zy) - (xz) = 0.1, two clamping angles will appear, namely:

[0071] When the third screw 210 rotates 13° with the magnetic rotating shaft 27, it clamps the wafer. Even though the chuck 13 rotates at 5000 r / min, no wafer is found to fly off.

[0072] When the third screw 210 rotates 90° with the magnetic rotating shaft 27, it will also clamp the wafer. Even if the chuck 13 rotates at 5000 r / min, no wafer is found to be thrown off.

[0073] At other rotation angles, once the rotation speed of chuck 13 exceeds 3000 r / min, a large number of concentric ripples will be found on the wafer surface during cleaning, and the wafer will be clearly shaking, with a risk of being thrown away.

[0074] Furthermore, by applying a fluorescent mark to the upper part of the pillar 53, the contact area remains constant when the edge of the wafer is supported by the upper part of the pillar 53. However, due to the eccentric setting, when the magnetic rotation shaft 27 rotates 13° and 90°, the wafer will change from the first clamping position to the second clamping position. Correspondingly, there will be two contact areas between the edge of the wafer and the upper part of the pillar 53, with a gap of 3-5mm between the two areas. In this way, the area in contact between the wafer and the upper part of the pillar 53 can be cleaned alternately, thereby ensuring that the edge of the wafer is thoroughly cleaned. Due to the setting of the first cone 32 and the second cone 23, there is no defect in the corresponding area of ​​the wafer edge that cannot be cleaned.

[0075] It should be noted that if (zy) = (xz) or (zy) - (xz) = 0.3, there will be no two clamping angles.

[0076] With the eccentricity being a constant value, after numerous experiments, the central angle corresponding to the limiting groove 251 was set to 90°. Thus, when the third screw 210 rotates synchronously with the magnetic rotating shaft 27, its maximum rotation angle is limited to 90° under the constraint of the limiting groove 251. When the rotation angle is 90°, the two rotating columns 21 can stop rotating after the outer circle of the wafer is close to the positioning component 30.

[0077] If the angle is too large, the wafer will not be clamped tightly; if the eccentricity is too large (such as 3mm), the wafer edge is easily damaged during rotation.

[0078] Optimally, the cone angle of the second cone 23 is 10° and the cone angle of the first cone 32 is 20°. The cone angle of the first cone 32 is not equal to the cone angle of the second cone 23. This is to allow the cleaning fluid to flow more smoothly downwards to clean the edge of the wafer.

[0079] If the cone angle of the first cone 32 is equal to that of the second cone 23, the cleaning solution may not flow smoothly at the edge of the wafer, which is detrimental to cleaning. According to the "Cleaning Effect Test," under these conditions, after 30 minutes of cleaning, there were still more than 110 particles on the lower surface of the wafer edge. However, in this invention, when the cone angle of the second cone 23 is 10° and the cone angle of the first cone 32 is 20°, the number of particles on the lower surface of the wafer edge drops to less than 30 after only 8 minutes of cleaning.

[0080] Cleaning Effectiveness Test

[0081] 100nm polystyrene latex particles are coated onto an 8-inch wafer to form a wafer to be cleaned. After pre-cleaning (cleaning processes can include acid washing, SPM cleaning, HQDR cleaning, SC1 cleaning, QDR cleaning, etc.), the number of particles on the wafer surface is controlled to be 5000±200. Then, it is placed into the magnetic clamping wafer double-sided cleaning rotary mechanism described in this invention for cleaning. The cleaning solution used on both the upper and lower surfaces of the wafer is water. During cleaning, the wafer rotation speed is maintained at 5000r / min, and the cleaning temperature is room temperature. The cleaning time required for the number of particles on the wafer surface to decrease to a specified number (e.g., 200, 100, etc.) is tested.

[0082] Example 6

[0083] like Figure 13 As shown, the upper surface of the back spray cover plate 40 is provided with raised textures. The raised textures are located on one side of the spray hole 41, and a through-hole groove is provided on the other side of the spray hole 41. The thickness of the raised textures is 1.1 mm, and the shape of the raised textures is the same as the shape of the through-hole groove. The raised textures include arc-shaped protrusions 421, and each end of the arc-shaped protrusions 421 is provided with a long strip-shaped extension 422. The included angle between the two extensions 422 is 137°. The side of the arc-shaped protrusions 421 closest to the spray hole 41 is provided with a straight... Part 1 423; The through-hole groove includes an arc-shaped hole 431, and elongated extension holes 432 are respectively provided at both ends of the arc-shaped hole 431. The included angle between the two extension holes 432 is 137°. A straight part 2 433 is provided on the side of the arc-shaped hole 431 near the spray hole 41. The vertical distance between the surface of the straight part 1 423 and the center of the spray hole 41 is m, and the vertical distance between the surface of the straight part 2 433 and the center of the spray hole 41 is n, where 1.05≤m / n≤1.2.

[0084] Firstly, this invention has little impact on the cleaning effect on the back side of the wafer when the back spray cover 40 is at a high rotation speed (e.g., greater than 3000 r / min). However, for some special cleaning processes, when the rotation speed for cleaning the front side of the wafer is generally less than 2000 r / min, the cleaning effect on the back side of the wafer is limited due to the limited number of nozzles 41 and the limited impact force of the spray (if the impact force is too large, the wafer may be thrown away). If the rotation speed of the wafer itself is not high enough, the cleaning effect near the edge of the wafer will be very limited.

[0085] In this embodiment, by setting up the embossed pattern and through-hole grooves, even when the wafer rotates at 600 r / min and is tested according to the "Cleaning Effect Test", the number of particles on the back of the wafer will decrease to less than 100 after a cleaning time of 10 minutes, especially the number of particles at the edge of the back of the wafer will decrease to less than 30.

[0086] Comparative Example 1

[0087] The back spray cover 40 does not have through holes or grooves, and is a flat plane. So, when the wafer is rotated at 600 r / min and tested according to the "Cleaning Effect Test", the cleaning time reaches 60 minutes, and the number of particles on the back of the wafer will exceed 2800.

[0088] Comparative Example 2

[0089] If the through-hole grooves are replaced with raised patterns, that is, there are two eccentrically set raised patterns, then when the wafer is rotated at 600 r / min and tested according to the "Cleaning Effect Test", the cleaning time reaches 60 minutes, and the number of particles on the back of the wafer is 2300±100.

[0090] Comparative Example 3

[0091] If the raised texture is replaced with through-hole grooves, that is, there are two eccentrically set through-hole grooves, then when the wafer is rotated at 600 r / min and tested according to the "Cleaning Effect Test", the cleaning time reaches 60 minutes, and the number of particles on the back of the wafer is 3500±100.

[0092] Comparative Example 4

[0093] If the thickness of the raised texture is too thick, reaching 5mm, then the wafer is tested at a rotation speed of 600r / min according to the "Cleaning Effect Test". The cleaning time reaches 60min, and the number of particles on the back of the wafer is 3900±100.

[0094] Comparative Example 5

[0095] The thickness of the raised texture is too thin, only 0.1 mm. Therefore, when the wafer is rotated at 600 r / min and tested according to the "Cleaning Effect Test", the cleaning time reaches 60 min, and the number of particles on the back of the wafer is 2700±100.

[0096] Comparative Example 6

[0097] If m = n, then when the wafer is rotated at 600 r / min and tested according to the "Cleaning Effect Test", the cleaning time reaches 60 min, and the number of particles on the back of the wafer is 2200 ± 100.

[0098] Comparative Example 7

[0099] If neither the flat section 2 (433) nor the flat section 1 (423) is set, the corresponding area will still be an arc-shaped structure. Then, when the wafer is rotated at 600 r / min and tested according to the "Cleaning Effect Test", the cleaning time reaches 60 min, and the number of particles on the back of the wafer is 1700±100.

[0100] In this embodiment, the use of raised textures and through-hole grooves ensures that even at a rotation speed of 600 r / min, the water jet sprayed from the center of the back spray cover 40 is radial, with a portion of it being evenly dispersed by the raised textures on one side. The alternating appearance of through-hole grooves and raised textures allows the water jet sprayed below the wafer to be diffused, increasing the impact range and enabling the wafer to be cleaned quickly even at lower rotation speeds (such as 600 r / min).

[0101] However, once the wafer is at a higher rotation speed (such as greater than 3000 r / min), the absence of ridges and through-hole grooves will not have a significant impact on wafer cleaning.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A magnetic clamping wafer double-sided cleaning rotary mechanism for performing double-sided cleaning on a wafer (1), characterized in that: It includes an upper cavity (10), a lower cavity (11) adapted to the upper cavity (10), a chuck (13) coaxially arranged with the upper cavity (10), a chuck mandrel (12) coaxially connected with the chuck (13), a gas-liquid separator (2), and a drain pump (4). The chuck mandrel (12) is a hollow structure, and a back spray cover plate (40) is provided on the top of the chuck mandrel (12). A spray hole (41) is provided in the center of the back spray cover plate (40); the chuck ( 13) A magnetic clamping mechanism for clamping the wafer (1) is provided on the upper part. Multiple waste discharge pipes (15) are provided at the lower part of the lower cavity (11). The inner cavity of the waste discharge pipe (15) is connected to the inner cavity of the lower cavity (11). All waste discharge pipes (15) are connected to the input end of the liquid discharge pump (4). The output end of the liquid discharge pump (4) is connected to the liquid inlet end of the gas-liquid separator (2). The gas-liquid separator (2) is provided with an exhaust pipe (3) and a liquid discharge pipe (5). The magnetic clamping mechanism includes at least one set of support units for supporting the wafer (1), at least one set of left clamping units for clamping the wafer (1), and at least one set of right clamping units for clamping the wafer (1). The support units, left clamping units, and right clamping units are all located on the edge of the chuck (13). The support unit includes two sets of support components (50), which are symmetrically arranged about the axis of the chuck (13). The left clamping unit and the right clamping unit both include positioning components (30), and the left clamping unit also includes a left clamping component (20). The right clamping unit also includes a right clamping component (20a). The positioning component (30) in the left clamping unit and the left clamping component (20) are symmetrically arranged about the axis of the chuck (13). The positioning component (30) in the right clamping unit and the right clamping component (20a) are symmetrically arranged about the axis of the chuck (13). A magnetic disk assembly (60) for driving the left clamping component (20) and the right clamping component (20a) to perform clamping actions is provided below the chuck (13). An movable port (101) is provided at the upper end of the upper cavity (10). The positioning component (30) includes a cylindrical second bottom post (31) fixedly installed on the side of the chuck (13). The upper end of the second bottom post (31) is provided with a first cone (32). The top of the first cone (32) is provided with a cylindrical second protrusion (33). The axis of the second protrusion (33) is eccentrically set with the axis of the second bottom post (31). The axis of the first cone (32) and the axis of the second protrusion (33) are coaxially set. The left clamping assembly (20) and the right clamping assembly (20a) have the same structure. Both the left clamping assembly (20) and the right clamping assembly (20a) include a support base (25) fixedly installed on the side of the chuck (13), a rotating column (21) rotatably connected to the support base (25), a magnetic rotating shaft (27) for driving the rotating column (21) to rotate, and a first screw (26) for connecting the magnetic rotating shaft (27) and the rotating column (21). The support base (25) is sleeved on the outside of the magnetic rotating shaft (27), and a self-aligning ball bearing (24) is installed between the upper part of the magnetic rotating shaft (27) and the support base (25). The upper part of the rotating column (21) is provided with a second cone (23). A cylindrical third protrusion (22) is coaxially arranged at the top of the two conical parts (23). The axis of the third protrusion (22) is eccentrically arranged with the axis of the rotating column (21). A cuboid permanent magnet (28) is arranged at the lower end of the magnetic rotating shaft (27). A second screw (211) is arranged on one side of the head end of the permanent magnet (28), and a third screw (210) is arranged on the other side of the tail end of the permanent magnet (28). A magnet cover (29) is fitted on the outside of the permanent magnet (28). The magnet cover (29) and the magnetic rotating shaft (27) are fixedly connected by the second screw (211) and the third screw (210). The permanent magnet (28) is arranged below the support base (25). The support assembly (50) includes a first bottom post (51) fixedly installed on the side of the chuck (13). The upper end of the first bottom post (51) is connected to a cylindrical column (53). The upper end of the column (53) is coaxially connected to a cylindrical first protrusion (52). The first protrusion (52) and the first bottom post (51) are eccentrically arranged. The magnetic disk assembly (60) includes a circular magnetic disk base (61), the edge of which is provided with an annular groove, and a plurality of driving magnets (62) for driving the permanent magnet (28) to rotate are provided in the annular groove. A magnetic disk cover plate (63) for covering all the driving magnets (62) is also fixedly installed on the magnetic disk base (61). A first through hole (611) for the lower part of the cassette spindle (12) to pass through is provided in the center of the magnetic disk base (61). An annular support groove (102) is provided at the bottom of the lower cavity (11). The magnetic disk base (61) is fixedly connected to the top of the support groove (102). The eccentricity between the axis of the third protruding post (22) and the axis of the rotating post (21) is 2.6 mm, the eccentricity between the axis of the second protruding post (33) and the axis of the second bottom post (31) is 1.7 mm, and the eccentricity between the first protruding post (52) and the first bottom post (51) is 2.2 mm.

2. The magnetic clamping wafer double-sided cleaning rotation mechanism according to claim 1, characterized in that: The chuck spindle (12) is coaxially provided with an inlet pipe (76). A transition sleeve (71) is connected between the back spray cover plate (40) and the upper part of the chuck spindle (12). A bearing (73) is connected between the inlet pipe (76) and the chuck spindle (12). A bearing gasket (74) is provided below the bearing (73). An elastic retaining ring (75) for supporting the bearing (73) is provided below the bearing gasket (74). A connecting sleeve (72) for connecting the upper end of the inlet pipe (76) is installed between the bearing (73) and the transition sleeve (71). The inner cavity of the inlet pipe (76) is connected to the spray hole (41).

3. The magnetic clamping wafer double-sided cleaning rotation mechanism according to claim 1, characterized in that: The lower part of the support base (25) is also provided with a limiting groove (251) for limiting the movement trajectory of the upper end of the third screw (210). The upper end of the third screw (210) extends out of the lower part of the magnetic rotation shaft (27) and the upper end of the third screw (210) is located in the limiting groove (251). The limiting groove (251) is an arc-shaped structure, and the central angle corresponding to the limiting groove (251) is 90°.

4. The magnetic clamping wafer double-sided cleaning rotation mechanism according to claim 1, characterized in that: The cone angle of the first cone (32) is not equal to the cone angle of the second cone (23).

5. The magnetic clamping wafer double-sided cleaning rotation mechanism according to claim 1, characterized in that: The upper surface of the back spray cover (40) is provided with raised textures, which are located on one side of the spray hole (41). A through-hole groove is provided on the other side of the spray hole (41). The thickness of the raised texture is 1.1 mm, and the shape of the raised texture is the same as that of the through-hole groove. The raised texture includes an arc-shaped protrusion (421), and long strip-shaped extensions (422) are provided at both ends of the arc-shaped protrusion (421). The included angle between the two extensions (422) is 137°. A straight section (422) is provided on the side of the arc-shaped protrusion (421) closest to the spray hole (41). 23); The through-hole groove includes an arc-shaped hole (431), and long strip-shaped extension holes (432) are respectively provided at both ends of the arc-shaped hole (431). The included angle between the two extension holes (432) is 137°. A straight part two (433) is provided on the side of the arc-shaped hole (431) near the nozzle (41). The vertical distance between the surface of the straight part one (423) and the center of the nozzle (41) is m, and the vertical distance between the surface of the straight part two (433) and the center of the nozzle (41) is n. 1.05≤m / n≤1.

2.

6. The magnetic clamping wafer double-sided cleaning rotation mechanism according to claim 5, characterized in that: The rotation speed of the back spray cover is 600~2000 r / min.

7. A magnetic clamping wafer double-sided cleaning rotating mechanism according to any one of claims 1-6, characterized in that: The rotational speed of the back spray cover is greater than 3000 r / min.

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