Dry polishing machine and dry polishing method

Abstract

The invention provides a dry type polishing machine and a dry type polishing method. The dry type polishing machine comprises a base, a rack, a rotary supporting part, a wafer bearing table, a polishing shaft, a dry polishing wheel and an air drying mechanism. The wafer bearing table is arranged on the rotary supporting part, the wafer bearing table is used for bearing a wafer, and the rotary supporting part is used for driving the bearing table to rotate. The upper end of the polishing shaft is installed on the rack, the dry polishing wheel is connected to the lower end of the polishing shaft and located above the wafer bearing table, and the polishing shaft is used for driving the dry polishing wheel to ascend, descend and rotate, so that the dry polishing wheel is tightly pressed on the wafer on the wafer bearing table and polishing the wafer; the air drying mechanism is arranged on the rack, the air drying mechanism is configured to alternately rotate to a first position and a second position before polishing so as to carry out air drying on the wafer on the wafer bearing table, the first position is located above the wafer and close to the edge of the wafer, and the second position is located above the wafer and close to the center of the wafer. According to the invention, automatic drying of the wafer is realized, the polishing cost is reduced, and the polishing efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of integrated circuit production, and in particular to a dry polishing machine and a dry polishing method. Background Art

[0002] After the wafer is cut and formed, the excess material on the back of the wafer needs to be removed by a thinning machine, thereby reducing the wafer packaging volume, reducing thermal resistance, and improving the heat dissipation performance of the device. At present, the grinding tool of the thinning machine is mainly a diamond grinding wheel. Diamond grinding wheel grinding uses the micro-cutting action of abrasive grains to remove materials, which inevitably produces a damaged layer on the surface and sub-surface of the wafer. In addition, due to the inconsistent height of the abrasive grains on the surface of the diamond grinding wheel, it is easy to leave tiny cracks and unevenly distributed wear marks on the surface of the wafer during the grinding process. Therefore, after the wafer is polished and thinned using a diamond grinding wheel, the wafer needs to be polished to remove damage on the surface and sub-surface of the wafer to eliminate stress and finally obtain a smooth and damage-free surface.

[0003] At present, the main polishing processes include Slurry (chemical polishing liquid) polishing, wet etching, dry polishing, etc. Slurry polishing is to remove materials by chemical and mechanical combined action. During the Slurry polishing process, the chemical polishing liquid is evenly distributed on the polishing pad, so that it contacts and reacts chemically with the surface material of the wafer, so that the damaged layer on the surface of the wafer forms a corrosion layer. At the same time, the polishing head rotates, so that friction occurs between the wafer material and the polishing pad, and the corrosion layer on the surface of the wafer is removed in time. Wet etching is to immerse the wafer in an acidic chemical solution (such as HN03 / HF / HP04) to remove the surface material of the wafer through chemical reaction. Dry polishing uses a polishing wheel (generally made of fiber and metal oxide) to polish the wafer to remove the surface stress of the silicon wafer. Compared with Slurry polishing and wet etching, dry polishing does not require the use of chemical reagents, which not only reduces the polishing cost, but also does not cause environmental pollution problems.

[0004] The dry polishing device is generally composed of a wafer stage and a polishing wheel arranged above the wafer stage. In order to ensure the dry polishing effect of the wafer, the wafer needs to be dried before polishing. The existing dry polishing device cannot dry the wafer. Therefore, before placing the wafer on the wafer stage, the wafer loader needs to transport the wafer to the drying equipment. After the drying equipment completes the drying of the wafer, the wafer is placed on the wafer stage. The existing wafer drying method requires special drying equipment to pre-dry the wafer, which increases the polishing cost and reduces the polishing efficiency. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides a dry polishing machine, which adopts the following technical solutions:

[0006] A dry polishing machine comprises a base, a frame, a rotating support part, a wafer receiving table, a polishing shaft, a dry polishing wheel and an air drying mechanism, wherein:

[0007] The rotating support part is arranged on the base, the wafer stage is arranged on the rotating support part, the wafer stage is used to carry the wafer, and the rotating support part is used to drive the carrying stage to rotate;

[0008] The frame is arranged on the base, the upper end of the polishing shaft is installed on the frame, the dry polishing wheel is connected to the lower end of the polishing shaft and is located above the wafer stage, and the polishing shaft is used to drive the dry polishing wheel to rise and fall and rotate, so that the dry polishing wheel is pressed against the wafer on the carrier, and the wafer is polished;

[0009] The air-drying mechanism is disposed on the frame, and is configured to rotate alternately to a first position and a second position before polishing to air-dry the wafer on the wafer stage, wherein the first position is located above the wafer and close to the edge of the wafer, and the second position is located above the wafer and close to the center of the wafer.

[0010] The use process of the dry polishing machine provided in this application is as follows:

[0011] First, place the wafer to be polished on the wafer stage and fix the wafer. Then, the rotating support part drives the stage and the wafer thereon to rotate. At the same time, the air-drying mechanism rotates alternately to the first position and the second position, so that the air-drying mechanism can alternately dry the peripheral area and the middle area of ​​the wafer. After the drying of the wafer is completed, the polishing shaft immediately performs the polishing operation on the wafer, thereby achieving seamless connection between drying and polishing. The dry polishing machine of the present application realizes automatic drying of the wafer, reduces the polishing cost, and improves the polishing efficiency.

[0012] In some embodiments, the air-drying mechanism includes a driving part, a connecting block and a blowing rod, wherein: the driving part is arranged on the frame; the connecting block is connected to the movable part of the driving part, an air cavity is arranged in the connecting block, and the air cavity is connected to an external compressed air source through an air connecting head; the blowing rod is horizontally connected to the connecting block and connected to the air cavity, and a plurality of blowing holes communicating with the air cavity are arranged at the end of the blowing rod, and the plurality of blowing holes are used for blowing air at a downward angle to implement air drying of the wafer; the driving part is used to drive the connecting block and the blowing rod to rotate synchronously, so as to drive the end of the blowing rod to rotate alternately to the first position and the second position.

[0013] The distance between the dry polishing wheel and the wafer stage is small, and a horizontally arranged blowing rod is used as the blowing component, which can ensure that the blowing rod can smoothly rotate to the first position and the second position between the dry polishing wheel and the wafer stage, and enable the blowing rod to sweep across the entire upper surface of the wafer as the wafer rotates, thereby improving the drying efficiency.

[0014] In some embodiments, the blowing rod includes a connecting section, a transition section and a blowing section, wherein: the connecting section is linear, and the first end of the connecting section is connected to the connecting block; the transition section is arc-shaped, and the first end of the transition section is connected to the second end of the connecting section; the blowing section is linear, and the first end of the blowing section is connected to the second end of the transition section, and the second end of the blowing section is closed, the blowing section constitutes the end of the blowing rod, and a plurality of blowing holes are arranged on the blowing section at intervals along the length direction of the blowing section; the driving part is used to drive the connecting block and the blowing rod to rotate synchronously, so as to drive the blowing section of the blowing rod to rotate alternately to a first position and a second position; the blowing section rotates to the first position, and the plurality of blowing holes blow downwardly at an angle to form a first air curtain intersecting with the upper surface of the wafer, and the rotating support part drives the carrier to rotate so that the first air curtain sweeps over the annular area on the circumferential side of the wafer; the blowing section rotates to the second position, and the plurality of blowing holes blow downwardly at an angle to form a second air curtain intersecting with the upper surface of the wafer, and the rotating support part drives the carrier to rotate so that the second air curtain sweeps over the circular area in the middle of the wafer.

[0015] By configuring the blowing rod to be composed of a connecting section, a transition section and a blowing section, and arranging the blowing holes on the blowing section at intervals along the length direction of the blowing section, an air curtain intersecting the upper surface of the wafer can be formed when a number of blowing holes are tilted downward to blow air, thereby implementing all-round drying of the upper surface of the wafer without dead angles, further improving the drying effect of the wafer.

[0016] In some embodiments, an angle of 30° to 60° is formed between the first air curtain, the second air curtain and the upper surface of the wafer.

[0017] The angle between the air curtain and the upper surface of the wafer is set to 30° to 60°, which can further improve the drying efficiency.

[0018] In some embodiments, the driving unit includes a mounting bracket, a motor and a rotating shaft, wherein: the mounting bracket is fixedly mounted on the frame, and the motor is arranged on the mounting bracket; the rotating shaft is rotatably mounted on the bracket and connected to the driving end of the motor through a coupling, and the connecting block is fixedly connected to the rotating shaft; the motor is used to drive the rotating shaft to rotate to drive the connecting block to rotate.

[0019] A driving part with a simple structure is provided, which can implement stable driving of the blowing rod and ensure that the end of the blowing rod can accurately stay at the first position and the second position.

[0020] In some embodiments, the driving unit further includes a trigger plate and a sensing element, wherein the trigger plate is disposed on the coupling, and the sensing element is disposed on the mounting bracket, and when the trigger plate rotates with the coupling and passes through the sensing element, the sensing element is triggered to generate a sensing signal.

[0021] Through the cooperation of the trigger sheet and the induction element, the driving unit realizes automatic counting of the number of alternating rotations of the blowing rod, ensuring that the driving unit stops driving the blowing rod to rotate after driving the blowing rod to rotate a predetermined number of times, thereby ensuring the drying effect.

[0022] In some embodiments, the sensing element is a proximity sensor, and when the trigger sheet approaches the proximity sensor, the proximity sensor is triggered to generate a sensing signal; alternatively, the sensing element includes a light emitter and a light receiver arranged upper and lower, and when the trigger sheet passes between the light emitter and the light receiver, the light path between the light emitter and the light receiver is blocked, and the light receiver generates a sensing signal.

[0023] Two sensing components with simple structures are provided, both of which can implement accurate sensing of the trigger sheet.

[0024] In some embodiments, the number of the blowing holes is 3 to 5, and the diameter of the blowing holes is 1 mm to 3 mm.

[0025] According to the size of the wafer, the number of the blowing holes and the aperture of the blowing holes are specifically set to ensure that the blowing holes can form a first air curtain and a second air curtain at the first position and the second position respectively, and ensure that the annular area swept by the first air curtain and the circular area swept by the second air curtain can cover the entire upper surface of the wafer.

[0026] In some embodiments, the wafer stage is provided with adsorption holes for adsorbing and fixing the wafer.

[0027] The wafer is adsorbed and fixed to prevent it from shifting during drying or polishing.

[0028] The present application also provides a dry polishing method, which is implemented by the dry polishing machine described in any one of the above items, and the dry polishing method comprises:

[0029] Place the wafer on the wafer stage;

[0030] Determining a first position and a second position adapted to the wafer;

[0031] Control the rotating support part to drive the bearing platform to rotate, and control the blowing hole at the end of the blowing rod to blow air;

[0032] The control driving unit drives the blowing rod to rotate, so that the end of the blowing rod rotates alternately to a first position and a second position, wherein the end of the blowing rod stays at the first position and the second position for a predetermined time each time when the end rotates to the first position and the second position;

[0033] When the number of times the end of the blowing rod alternately rotates reaches a predetermined number, the control driving unit drives the blowing rod to rotate, so that the end of the blowing rod rotates to the avoidance position located on the side of the wafer holding table;

[0034] The polishing shaft is controlled to drive the polishing wheel to descend and rotate, so as to drive the polishing shaft to polish the dried wafer.

[0035] The dry polishing method provided in the present application completes automatic drying of the wafer before polishing, achieving seamless connection between drying and polishing, thereby reducing polishing costs and improving polishing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural schematic diagram of some components of the dry polishing machine in an embodiment of the present application;

[0037] Figure 2 It is a schematic diagram of the structure of the air-drying mechanism in the embodiment of the present application at one viewing angle;

[0038] Figure 3 It is a schematic diagram of the structure of the air-drying mechanism in the embodiment of the present application from another perspective;

[0039] Figure 4 It is a schematic diagram of the drying process in which the end portion (blowing section) of the blowing rod in the embodiment of the present application rotates to the first position;

[0040] Figure 5 It is a schematic diagram of the drying process in which the end portion (blowing section) of the blowing rod rotates to the second position in the embodiment of the present application.

[0041] Figures 1 to 5 Included:

[0042] Film table 1;

[0043] Polishing shaft 2;

[0044] Dry throwing wheel 3;

[0045] Air-drying mechanism 4: driving part 41, mounting bracket 411, motor 412, rotating shaft 413, coupling 414, connecting block 42, blowing rod 43, connecting section 431, transition section 432, blowing section 433, blowing hole 434;

[0046] Wafer 100. DETAILED DESCRIPTION

[0047] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0048] like Figure 1 As shown, the dry polishing machine in the embodiment of the present application includes a base, a frame, a rotating support part, a wafer carrier 1, a polishing shaft 2, a dry polishing wheel 3 and an air drying mechanism 4, wherein:

[0049] The rotating support part is arranged on the base, the wafer stage 1 is arranged on the rotating support part, the wafer stage 1 is used to carry and fix the wafer, and the rotating support part is used to drive the wafer stage 1 to rotate. The rotating support part can be, for example, a rotating table driven by a rotating motor, the wafer stage 1 is installed on the rotating table, and the rotating motor drives the rotating table to rotate, which drives the wafer stage 1 to rotate synchronously.

[0050] The frame is arranged on the base, the upper end of the polishing shaft 2 is installed on the frame, the dry polishing wheel 3 is connected to the lower end of the polishing shaft 2 and is located above the wafer support table 1, and the polishing shaft 2 is used to drive the dry polishing wheel 3 to rise and fall and rotate, so that the dry polishing wheel 3 is pressed against the wafer on the support table 1 and polishes the wafer.

[0051] The air drying mechanism 4 is arranged on the frame, and is configured to rotate alternately to a first position and a second position before polishing to air dry the wafer on the wafer stage 1, wherein the first position is located above the wafer and close to the edge of the wafer, and the second position is located above the wafer and close to the center of the wafer.

[0052] The use process of the dry polishing machine provided in this application is as follows:

[0053] First, place the wafer to be polished on the wafer stage 1 and fix the wafer.

[0054] Subsequently, the rotating support drives the carrier 1 and the wafer thereon to rotate, and at the same time, the air-drying mechanism 4 rotates alternately to the first position and the second position, so that the air-drying mechanism 4 can alternately dry the peripheral area and the middle area of ​​the wafer.

[0055] After the wafer is dried, the polishing shaft 2 drives the dry polishing wheel 3 to descend, so that the dry polishing wheel 3 contacts the wafer, and then the polishing shaft 2 drives the dry polishing wheel 3 to rotate to perform the polishing operation on the wafer. In order to further improve the polishing effect of the dry polishing wheel 3, the rotation direction of the dry polishing wheel 3 is opposite to the rotation direction of the wafer.

[0056] The dry polisher of the present application realizes automatic drying of the wafer, and realizes seamless connection between drying operation and polishing operation, reduces polishing cost and improves polishing efficiency. In particular, the air-drying mechanism 4 rotates alternately to the first position and the second position during the air-drying process to implement alternating drying of the peripheral area and the middle area. Compared with keeping the air-drying mechanism 4 in the same position to implement air-drying, the swing-type alternating air-drying can implement disturbance of the surrounding air, so that the agitated air forms an airflow and then flows rapidly along the surface of the wafer, thereby further improving the drying efficiency of the wafer surface.

[0057] The polishing shaft 2 can adopt a spindle commonly used in the art for driving the dry polishing wheel 3 to rise and fall and rotate, such as an air-floating spindle.

[0058] like Figures 2 to 3 As shown, optionally, the air-drying mechanism 4 includes a driving part 41, a connecting block 42 and a blowing rod 43, wherein: the driving part 41 is arranged on the frame. The connecting block 42 is connected to the movable part of the driving part 41, and an air cavity is arranged in the connecting block 42, and the air cavity is connected to an external compressed air source through an air connector. The blowing rod 43 is horizontally connected to the connecting block 42 and is connected to the air cavity, and a plurality of blowing holes communicating with the air cavity are arranged at the end of the blowing rod 43, and the plurality of blowing holes are used for blowing air at a downward angle to implement air drying of the wafer. The driving part 41 is used to drive the connecting block 42 and the blowing rod 43 to rotate synchronously, so as to drive the end of the blowing rod 43 to rotate alternately to the first position and the second position.

[0059] Since the distance between the dry polishing wheel 3 and the wafer stage 1 is small, a horizontally arranged blowing rod 43 is used as a blowing component to ensure that the blowing rod 43 can smoothly rotate to the first position and the second position between the dry polishing wheel 3 and the wafer stage 1, and enable the blowing rod 43 to sweep across the entire upper surface of the wafer as the wafer rotates, thereby improving the drying efficiency.

[0060] In addition, the blowing holes are concentrated only at the end of the blowing rod 43, so the number of blowing holes required is small, so that the compressed air can be blown out from the end of the blowing rod 43 at a higher speed. In addition, when the end of the blowing rod 43 rotates and switches between the first position and the second position, the surrounding air can be disturbed to a greater extent, further improving the drying effect.

[0061] Optionally, the blowing rod 43 includes a connecting section 431, a transition section 432 and a blowing section 433, wherein: the connecting section 431 is linear, and the first end of the connecting section 431 is connected to the connecting block 42. The transition section 432 is arc-shaped, and the first end of the transition section 432 is connected to the second end of the connecting section 431. The blowing section 433 is linear, and the first end of the blowing section 433 is connected to the second end of the transition section 432, and the second end of the blowing section 433 is closed, and the blowing section 433 constitutes the end of the blowing rod 43, and a plurality of blowing holes 434 are arranged at intervals at the bottom of the blowing section 433 along the length direction of the blowing section 433. The driving part 41 is used to drive the connecting block 42 and the blowing rod 43 to rotate synchronously, so as to drive the blowing section 433 of the blowing rod 43 to rotate alternately to the first position and the second position.

[0062] like Figure 4 As shown, when the blowing section 433 rotates to the first position, the plurality of blowing holes 434 blow downwardly at an angle to form a first air curtain intersecting the upper surface of the wafer 100. The carrier 1 drives the wafer 100 to rotate (counterclockwise in the figure) under the drive of the rotating support portion, so that the first air curtain sweeps the annular area A around the wafer 100.

[0063] like Figure 5As shown, when the blowing section 433 rotates to the second position, the plurality of blowing holes 434 blow downwardly at an angle to form a second air curtain intersecting the upper surface of the wafer 100. The carrier 1 drives the wafer 100 to rotate (counterclockwise in the figure) under the drive of the rotating support portion, so that the second air curtain sweeps across the circular area B in the middle of the wafer 100.

[0064] By setting the length and angle of the blowing section 433 , the annular area A and the circular area B can cover the entire upper surface of the wafer 100 , thereby achieving all-round drying of the upper surface of the wafer 100 without dead corners, further improving the drying effect of the wafer 100 .

[0065] Optionally, by setting the blowing direction of the plurality of blowing holes 434 , an angle of 30° to 60° is formed between the first air curtain, the second air curtain and the upper surface of the wafer, thereby further improving the blowing effect of the blowing section 433 on the wafer 100 .

[0066] like Figures 2 to 3 As shown, optionally, the driving part 41 includes a mounting bracket 411, a motor 412 and a rotating shaft 413, wherein: the mounting bracket 411 is fixedly mounted on the frame, and the motor 412 is arranged on the mounting bracket 411. The rotating shaft 413 is rotatably mounted on the bracket and connected to the driving end of the motor 412 through a coupling 414, and the connecting block 42 is fixedly connected to the rotating shaft 413. The motor 412 drives the rotating shaft to rotate stably through the coupling 414, thereby driving the connecting block 42 and the blowing rod 43 to rotate synchronously, ensuring that the end of the blowing rod 43 can accurately stay at the first position and the second position.

[0067] Optionally, the number of the blowing holes 434 is 3 to 5, and the aperture of the blowing holes 434 is 1 mm to 3 mm. In a specific embodiment, the number and aperture of the blowing holes 434 can be specifically set according to the specific size of the wafer to ensure that the blowing holes 434 can cooperate with each other to form a first air curtain and a second air curtain at the first position and the second position respectively, and ensure that the annular area swept by the first air curtain and the circular area swept by the second air curtain can cover the entire upper surface of the wafer 100.

[0068] like Figures 2 to 3 As shown, optionally, the driving part 41 further includes a trigger sheet 415 and a sensing element 416, wherein the trigger sheet 415 is disposed on the coupling 414, and the sensing element 416 is disposed on the mounting bracket, and when the trigger sheet 415 rotates with the coupling 414 and passes through the sensing element 416, the sensing element 416 is triggered to generate a sensing signal.

[0069] Through the cooperation of the trigger sheet 415 and the induction element 416, the driving unit 41 can realize automatic counting of the number of alternate rotations of the blowing rod 43, ensuring that the driving unit 41 stops driving the blowing rod 43 to rotate for a predetermined number of times, thereby ending the drying process. While ensuring the drying effect, it prevents the drying time from being too long to reduce the polishing efficiency.

[0070] Optionally, the sensing element 416 is a proximity sensor, and when the trigger sheet 415 approaches the proximity sensor, the proximity sensor is triggered to generate a sensing signal. Alternatively, the sensing element 416 includes a light emitter and a light receiver arranged up and down, and when the trigger sheet 415 passes between the light emitter and the light receiver, the light path between the light emitter and the light receiver is blocked, thereby triggering the light receiver to generate a sensing signal.

[0071] Based on the same inventive concept, the present application also provides a dry polishing method, which is implemented by the dry polishing machine in any of the above embodiments, and the dry polishing method includes:

[0072] S1. Place the wafer on the wafer stage.

[0073] S2. Determine a first position and a second position that match the wafer.

[0074] Different sizes of wafers have different first and second positions that match them. The first and second positions corresponding to wafers of different sizes can be obtained through preliminary tests and stored for later use. Therefore, before drying the current wafer, the first and second positions corresponding to it can be directly obtained.

[0075] S3, controlling the rotating support part to drive the bearing platform to rotate, and controlling the blowing hole at the end of the blowing rod to blow air.

[0076] S4. Control the driving unit to drive the blowing rod to rotate, so that the end of the blowing rod rotates to the first position and the second position alternately, wherein the end of the blowing rod stays at the first position and the second position for a predetermined time each time it rotates to the first position and the second position.

[0077] The specific time that the end of the blowing rod stays at the first position and the second position is related to the rotation speed of the carrier, and it is necessary to ensure that the airflow blown by the end of the blowing rod can at least sweep the wafer once during the stay time. For example, in some embodiments, the time for the wafer to rotate once is 1.5 seconds, and the end of the blowing rod stays for 3 seconds each time it rotates to the first position and the second position.

[0078] S4. When the number of times the end of the blowing rod alternately rotates reaches a predetermined number, the driving unit drives the blowing rod to rotate, so that the end of the blowing rod rotates to the avoidance position located on the side of the wafer holding table.

[0079] The number of times the end of the blowing rod rotates alternately can be adaptively set according to the length of time the end of the blowing rod stays at the first position and the second position each time and the rotation speed of the carrier. The specific value is based on the drying standard that can meet the wafer.

[0080] S5. Control the polishing shaft to drive the polishing wheel to descend and rotate, so as to drive the polishing shaft to polish the dried wafer.

[0081] During the polishing process, the rotating support portion of the polishing shaft keeps driving the carrier to rotate. In order to improve the polishing efficiency, the rotation direction of the polishing wheel can be opposite to the rotation direction of the carrier.

[0082] In addition, for wafers of different sizes, parameters such as the rotation speed of the carrier, the rotation speed of the blowing rod, and the air flow blowing speed of the blowing rod can be adaptively set according to the specific size of the wafer to ensure the drying effect of the wafer.

[0083] The dry polishing method provided in the embodiment of the present application completes automatic drying of the wafer before polishing, achieving seamless connection between drying and polishing, which reduces polishing costs and improves polishing efficiency.

[0084] The present application is described in sufficient detail above with certain particularity. It should be understood by those skilled in the art that the description in the embodiments is merely exemplary, and all changes made without departing from the true spirit and scope of the present application should fall within the scope of protection of the present application. The scope of protection claimed in the present application is defined by the claims, rather than by the above description in the embodiments.

Claims

1. A dry polishing machine, characterized in that: The dry polishing machine comprises a base, a frame, a rotating support, a wafer receiving table, a polishing shaft, a dry polishing wheel and an air drying mechanism, wherein: The rotating support part is arranged on the base, the wafer stage is arranged on the rotating support part, the wafer stage is used to carry the wafer, and the rotating support part is used to drive the wafer stage to rotate; The frame is arranged on the base, the upper end of the polishing shaft is mounted on the frame, the dry polishing wheel is connected to the lower end of the polishing shaft and is located above the wafer stage, and the polishing shaft is used to drive the dry polishing wheel to rise and fall and rotate, so that the dry polishing wheel is pressed against the wafer on the carrier and polishes the wafer; The air-drying mechanism is disposed on the frame, and is configured to rotate alternately to a first position and a second position before polishing to air-dry the wafer on the wafer stage, wherein the first position is located above the wafer and close to the edge of the wafer, and the second position is located above the wafer and close to the center of the wafer.

2. The dry polishing machine according to claim 1, characterized in that: The air-drying mechanism comprises a driving part, a connecting block and a blowing rod, wherein: The driving unit is arranged on the frame; The connecting block is connected to the movable part of the driving part, and an air cavity is arranged in the connecting block, and the air cavity is connected to an external compressed air source through an air connector; The blowing rod is horizontally connected to the connecting block and communicates with the air cavity. The end of the blowing rod is provided with a plurality of blowing holes communicated with the air cavity. The plurality of blowing holes are used for blowing air in a downward direction to implement air drying of the wafer. The driving part is used to drive the connecting block and the blowing rod to rotate synchronously, so as to drive the end of the blowing rod to rotate alternately to the first position and the second position.

3. The dry polishing machine according to claim 2, characterized in that, The blowing rod comprises a connecting section, a transition section and a blowing section, wherein: The connecting section is linear, and a first end of the connecting section is connected to the connecting block; The transition section is arc-shaped, and the first end of the transition section is connected to the second end of the connecting section; The blowing section is linear, the first end of the blowing section is connected to the second end of the transition section, the second end of the blowing section is closed, the blowing section constitutes the end of the blowing rod, and a plurality of blowing holes are arranged on the blowing section at intervals along the length direction of the blowing section; The driving part is used to drive the connecting block and the blowing rod to rotate synchronously, so as to drive the blowing section of the blowing rod to rotate alternately to the first position and the second position; The blowing section rotates to the first position, and the plurality of blowing holes blow air downwardly at an angle to form a first air curtain intersecting with the upper surface of the wafer, and the rotating support portion drives the carrier to rotate so that the first air curtain sweeps over the annular area on the circumference of the wafer; The blowing section rotates to the second position, and the plurality of blowing holes blow air downward at an angle to form a second air curtain intersecting with the upper surface of the wafer. The rotating support portion drives the carrier platform to rotate, so that the second air curtain sweeps across a circular area in the middle of the wafer.

4. The dry polishing machine according to claim 3, characterized in that: An included angle of 30° to 60° is formed between the first air curtain, the second air curtain and the upper surface of the wafer.

5. The dry polishing machine according to claim 2, characterized in that: The driving unit includes a mounting bracket, a motor and a rotating shaft, wherein: The mounting bracket is fixedly mounted on the frame, and the motor is arranged on the mounting bracket; The rotating shaft is rotatably mounted on the bracket and connected to the driving end of the motor through a coupling, and the connecting block is fixedly connected to the rotating shaft; The motor is used to drive the rotating shaft to rotate so as to drive the connecting block to rotate.

6. The dry polishing machine according to claim 5, characterized in that: The driving part further comprises a triggering piece and a sensing element, wherein the triggering piece is arranged on the coupling, and the sensing element is arranged on the mounting bracket. When the triggering piece rotates with the coupling and passes through the sensing element, the sensing element is triggered to generate a sensing signal.

7. The dry polishing machine according to claim 6, characterized in that: The sensing element is a proximity sensor, and when the trigger sheet approaches the proximity sensor, the proximity sensor is triggered to generate a sensing signal; Alternatively, the sensing element includes a light emitter and a light receiver arranged vertically, and when the trigger sheet passes between the light emitter and the light receiver, the light path between the light emitter and the light receiver is blocked, and the light receiver generates a sensing signal.

8. The dry polishing machine according to claim 4, characterized in that: The number of the blowing holes is 5, and the diameter of the blowing holes is 1 mm to 3 mm.

9. The dry polishing machine according to claim 2, characterized in that: The wafer stage is provided with adsorption holes for adsorbing and fixing the wafer.

10. A dry polishing method, characterized in that: The dry polishing method is implemented by the dry polishing machine according to any one of claims 2 to 9, and comprises: placing a wafer on the wafer stage; determining a first position and a second position adapted to the wafer; Control the rotating support part to drive the bearing platform to rotate, and control the blowing hole at the end of the blowing rod to blow air; The control driving unit drives the blowing rod to rotate, so that the end of the blowing rod rotates to the first position and the second position alternately, wherein the end of the blowing rod stays at the first position and the second position for a predetermined time each time when the end rotates to the first position and the second position; When the number of times the end of the blowing rod alternately rotates reaches a predetermined number, the control driving unit drives the blowing rod to rotate, so that the end of the blowing rod rotates to the avoidance position located on the side of the wafer holding table; The polishing shaft is controlled to drive the polishing wheel to descend and rotate, so as to drive the polishing shaft to polish the wafer that has been dried.

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