Epitaxial wafer back side flatness processing device and processing method

Abstract

The present invention discloses an epitaxial wafer back flatness processing device and processing method, which relates to the field of epitaxial wafer processing technology, including an adsorption part, a positioning part, a grinding part, a protective part and a liquid discharge part. Also disclosed is an epitaxial wafer back flatness processing method, including the following steps: placement, adsorption, positioning, grinding treatment and material discharge. The present invention sets an adsorption part, when the adsorption part moves to a first height, the epitaxial wafer contacts the top surface of the carrier platform, and at the same time drives the positioning part to position the epitaxial wafer, so that the epitaxial wafer and the carrier platform are in a concentric position, and then the adsorption part moves to a second height and fixes the epitaxial wafer, and in the process of the adsorption part moving to the first height, the gas discharged from the ventilation inclined hole cleans the top surface of the carrier platform, thereby improving the overall quality of the epitaxial wafer; through the cooperation of the protective part and the adsorption part, the increased air pressure during the inflation process of the protective cover is used to clear the drainage pipe, which is convenient for the continuous processing of the epitaxial wafer.

Description

Technical Field

[0001] The invention belongs to the technical field of epitaxial wafer processing, and in particular relates to an epitaxial wafer back surface flatness processing device and a processing method. Background Art

[0002] In the field of semiconductor manufacturing, epitaxial wafers are a key material, which are prepared by growing one or more thin layers with specific electrical properties on a single crystal substrate. These thin layers are usually composed of semiconductor materials such as silicon, gallium arsenide, indium phosphide, etc., and are used to manufacture various microelectronic and optoelectronic devices, such as integrated circuits, transistors, photodetectors, etc.

[0003] A Chinese patent with application number 202011085594.2 discloses a wafer centering mechanism, a wafer transmission device and a wafer thinning device. The wafer centering mechanism includes a fixed table, a rotary drive mechanism, a bevel gear assembly, a preset number of ball screw assemblies and a preset number of mobile clamping assemblies; a preset number of ball screw assemblies are evenly installed on the fixed table along the circumferential direction, the ball screw assembly is arranged in the horizontal direction, the linear motion end of the ball screw assembly is connected to the mobile clamping assembly, the ball screw assembly is located outside the bevel gear assembly and the rotating end of the ball screw assembly is fixedly connected to the bevel gear assembly, and the bevel gear assembly is fixedly connected to the rotary drive mechanism located therebelow, which can improve the reliability of wafer adsorption and the surface quality of wafer grinding.

[0004] However, it was found in actual production that the above technical solution still has problems: the platform for placing the epitaxial wafers in the above solution is contaminated by the outside air or the particles carried during the transportation of the epitaxial wafers fall onto the platform, resulting in scratches or dents on the surface of the epitaxial wafers, affecting the overall quality of the epitaxial wafers after processing; and the grinding liquid used when grinding the epitaxial wafers is affected by the rotation of the platform, and the grinding liquid is splashed to every corner of the device, making it inconvenient to recover the grinding liquid.

[0005] Therefore, it is necessary to invent an epitaxial wafer back side flatness processing device and a processing method to solve the above-mentioned problems. Summary of the invention

[0006] The purpose of the present invention is to provide an epitaxial wafer back side flatness processing device and a processing method in view of the above-mentioned existing technical problems, so as to solve the problems raised in the above-mentioned background technology.

[0007] The present invention provides an epitaxial wafer back flatness processing device, comprising a cabinet, and also comprising: a base, which is fixedly arranged inside the cabinet, and the base is a convex structure; an adsorption part, which is arranged on the top of the base, and the adsorption part can adsorb and fix the epitaxial wafer, and can drive the epitaxial wafer to rotate around the top of the base; a positioning part, the number of which is set to multiple groups, and multiple groups of the positioning parts are adjustably arranged on the top of the base, and the synchronous movement of the multiple groups of the positioning parts can adjust the epitaxial wafer to a position concentric with the adsorption part; a grinding part, which is fixedly arranged inside the cabinet and located above the adsorption part, and the grinding part drives the epitaxial wafer to rotate in the forward direction under the cooperation with the adsorption part, and the grinding part starts to rotate in the reverse direction after contacting the back of the epitaxial wafer; a protective part, which is fixedly arranged on the outer wall of the grinding part, and the protective part can move up and down synchronously with the grinding part; a liquid discharge part, which is opened on the top of the base and is used to discharge liquid.

[0008] Preferably, the adsorption part includes: a supporting platform, which is rotatably arranged on the top of the base; an annular cylinder, which is fixedly arranged on the bottom of the base; a T-shaped plate, which is sealingly slidably arranged in the annular cylinder and can move up and down along the annular cylinder; an annular plate, which is fixedly arranged at the bottom of the T-shaped plate; electric telescopic parts, which are arranged in multiple groups, and the fixed ends of the multiple groups of electric telescopic parts are fixedly arranged at the bottom of the supporting platform, and the protruding ends of the multiple groups of electric telescopic parts are fixedly arranged at the top of the annular plate.

[0009] Preferably, the adsorption part also includes: support tubes, which are arranged in multiple groups, and the bottoms of the multiple groups of support tubes are fixedly arranged on the tops of the annular plates, and the tops of the multiple groups of support tubes can slide up and down along the supporting platform in a sealed manner; connecting tubes, which are arranged in multiple groups and correspond to the support tubes, and one end of the connecting tubes is connected to the support tubes, and the other end is connected to the side wall of the top of the annular tube; an annular cavity, which is opened on the outer wall of the supporting platform, and the annular cavity is sealed with the inner side wall of the top of the base; gas channels, which are arranged in multiple groups, which are opened inside the supporting platform, and the multiple groups of gas channels are used to connect the annular cavity with the top of the annular tube.

[0010] Preferably, the adsorption part further comprises: ventilation inclined holes, which are arranged in a plurality of groups and opened at the top of the corresponding support tube, and are used for ventilation and suction.

[0011] Preferably, the positioning part includes: rotating columns, which are arranged in multiple groups, and the multiple groups of rotating columns are rotatably arranged in the top of the base; positioning cams, which are arranged in multiple groups and correspond to the rotating columns, and the bottoms of the multiple groups of positioning cams are fixedly connected to the tops of the multiple groups of rotating columns; driving gears, which are arranged in multiple groups, and the tops of the multiple groups of driving gears are fixedly arranged with the corresponding rotating columns; air flow channels, which are arranged in multiple groups, and the multiple groups of air flow channels are opened in the top of the base, and the multiple groups of air flow channels are connected with the annular cavity; pushing plates, which are arranged in multiple groups and correspond to the air flow channels, and are slidably arranged in the air flow channels; tooth plates, which are arranged in multiple groups and correspond to the pushing plates, and the multiple groups of tooth plates are fixedly arranged with one end of the corresponding pushing plates, the multiple groups of tooth plates slide in the multiple groups of air flow channels, and one end of the multiple groups of tooth plates are meshed with the corresponding driving gears.

[0012] Preferably, the grinding part includes: a driving member, which is fixedly arranged inside the cabinet and located above the supporting platform, and a first driving motor is fixedly arranged at the bottom of the driving member; and a grinding disc, the top of which is fixedly arranged at the driving end of the first driving motor.

[0013] Preferably, the protective part includes: a protective cover, which is fixedly arranged on the outer side wall of the bottom of the driving member and is located above the grinding disk; a first annular pad, which is arranged on the inner side wall of the bottom of the protective cover; a second annular pad, which is arranged on the outer side wall of the top of the base, and the second annular pad cooperates with the first annular pad to form a seal for the inside of the protective cover.

[0014] Preferably, the liquid discharge part also includes: an annular chute, which is opened in the top of the base, and the end of the annular chute close to the grinding disk is higher, and the end away from the grinding disk is lower, and the whole is an annular slope; filter holes, which are arranged in multiple groups and opened on the upper surface of the top of the base, and the bottoms of the multiple groups of filter holes are connected to the annular chute; a drain pipe, the top of which is connected to the bottom of the lower end of the annular chute, for discharging the liquid in the annular chute.

[0015] Preferably, it also includes: a second driving motor, the bottom of which is fixedly arranged inside the base, and the driving end of which is fixedly arranged on the bottom of the supporting platform.

[0016] The present invention also discloses a method for processing the flatness of the back side of an epitaxial wafer, comprising the following steps:

[0017] Step 1: Place the epitaxial wafer on the top surface of the plurality of support tubes by using a robot or manually holding the epitaxial wafer;

[0018] Step 2: Adsorption: fix the placed epitaxial wafer on the top surface of the carrier platform through the adsorption part;

[0019] Step 3: Positioning: When the adsorption unit moves the epitaxial wafer downward to the first height, the positioning unit positions the epitaxial wafer so that the epitaxial wafer is concentric with the carrier;

[0020] Step 4: grinding, the grinding unit moves downward and contacts the epitaxial wafer, then the second drive motor drives the carrier and the epitaxial wafer to rotate forward, and the grinding unit rotates in the reverse direction to grind the epitaxial wafer;

[0021] Step 5: Unloading: Move the adsorption part upward to the initial position and remove the epitaxial wafer.

[0022] The beneficial effects of the present invention are:

[0023] 1. The present invention arranges an adsorption part, and places the epitaxial wafer on the top of multiple groups of support tubes by a robot or manual hand, and then the electric telescopic parts drive the multiple groups of support tubes to move to a first height and flush with the top of the supporting platform. In the process of the multiple groups of support tubes moving downward, the T-shaped plate moves downward along the annular tube and squeezes the gas under it. The squeezed gas is discharged from the vent hole through the connecting pipe and the support tube and cleans the particles and impurities on the top surface of the supporting platform, avoiding scratches or dents on the bottom of the epitaxial wafer caused by particles and impurities, thereby improving the overall quality of the epitaxial wafer.

[0024] 2. The present invention cooperates with the adsorption part and the positioning part. When the adsorption part moves to a first height, the epitaxial wafer contacts the top surface of the carrier table, and at the same time drives the positioning part to position the epitaxial wafer and adjust the epitaxial wafer to a concentric position with the carrier table. The adsorption part then moves to a second height to fix the epitaxial wafer and at the same time drives the positioning part to break away from contact with the edge of the epitaxial wafer, preventing damage to the edge of the epitaxial wafer during rotation, thereby improving the overall quality and yield rate of the epitaxial wafer.

[0025] 3. The present invention provides a liquid discharge portion, and the grinding liquid used in grinding is thrown out during the high-speed rotation of the epitaxial wafer. At this time, the thrown-out grinding liquid flows along the filter holes into the annular chute. Since the end of the annular chute close to the grinding disk is higher and the end away from the grinding disk is lower, the whole is an annular inclined surface. The grinding liquid flows along the high point of the annular chute to the low point and is discharged to a designated place outside through the drainage pipe, which is convenient for the recovery of the grinding liquid.

[0026] 4. The present invention sets a protective part. When the drain pipe is blocked by the abrasive particles carried in the grinding liquid, the driving part drives the protective cover and the first annular pad to move, so that the first annular pad contacts the second annular pad and stops moving. Then the electric telescopic part drives the annular plate and the support tube and other components to move up and down to inflate and suck air in the protective cover. The increase in air pressure during the inflation process of the protective cover is used to clear the drain pipe, thereby ensuring the continuity of the processing work. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0028] Figure 2 It is a schematic diagram of the internal cross-section of the base of the present invention.

[0029] Figure 3 It is a schematic diagram of the structure of the adsorption part of the present invention.

[0030] Figure 4 It is a schematic diagram of the positioning part structure of the present invention.

[0031] Figure 5 It is a schematic diagram of the matching structure of the protection part and the base of the present invention.

[0032] Figure 6 The present invention Figure 5 Enlarged structural diagram at A in the middle.

[0033] Figure 7 It is a schematic diagram of the initial position structure of the epitaxial wafer and the support tube of the present invention.

[0034] Figure 8 It is a schematic diagram of the first height structure of the epitaxial wafer and the support tube of the present invention.

[0035] Fig. 9 It is a schematic diagram of the second height structure of the epitaxial wafer and the support tube of the present invention.

[0036] In the figure: 1, cabinet; 2, base; 3, adsorption part; 4, positioning part; 5, grinding part; 6, protection part; 7, liquid discharge part; 8, second drive motor; 301, support platform; 302, annular cylinder; 303, T-shaped plate; 304, annular plate; 305, electric telescopic member; 306, support cylinder; 307, connecting pipe; 308, annular cavity; 309, gas channel; 310, ventilation oblique hole; 401, rotating column; 402, positioning cam; 403, driving gear; 404, air flow channel; 405, pushing plate; 406, tooth plate; 501, driving member; 502, first drive motor; 503, grinding disc; 601, protective cover; 602, first annular pad; 603, second annular pad; 701, annular chute; 702, filter hole; 703, drain pipe. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0038] Embodiment 1, the present invention provides as Figures 1 to 9 The device for processing the flatness of the back side of the epitaxial wafer shown includes a cabinet 1, and also includes: a base 2, which is fixedly arranged inside the cabinet 1, and the base 2 is a convex structure; an adsorption portion 3, which is arranged on the top of the base 2, and the adsorption portion 3 can adsorb and fix the epitaxial wafer, and can drive the epitaxial wafer to rotate around the top of the base 2.

[0039] The carrier 301 is rotatably arranged on the top of the base 2; the annular cylinder 302 is fixedly arranged on the bottom of the base 2; the T-shaped plate 303 is sealed and slidably arranged in the annular cylinder 302, and can move up and down along the annular cylinder 302. The T-shaped plate 303 divides the annular cylinder 302 into two parts, the upper part of the gas flows into the positioning part 4 to realize the positioning of the epitaxial wafer by the positioning part 4, and the lower part of the gas is used to clean the particles on the top surface of the carrier 301 to improve the overall quality of the epitaxial wafer; the annular plate 304 is fixedly arranged at the bottom of the T-shaped plate 303, which can drive the T-shaped plate 303 to move upward and downward. 03 moves up and down along the annular cylinder 302; the electric telescopic parts 305 are electrically connected to the control system, and the number is set to multiple groups, and the fixed ends of the multiple groups of electric telescopic parts 305 are fixedly set at the bottom of the supporting platform 301, and the protruding ends of the multiple groups of electric telescopic parts 305 are fixedly set at the top of the annular plate 304; the support cylinder 306, the top of which is made of rubber material to avoid damage to the surface of the epitaxial wafer, and the number is set to multiple groups, and the bottoms of the multiple groups of support cylinders 306 are fixedly set at the top of the annular plate 304, and the tops of the multiple groups of support cylinders 306 can slide up and down along the supporting platform 301 in a sealed manner.

[0040] The connecting tube 307 is provided in multiple groups and corresponds to the support tube 306, and one end of the connecting tube 307 is connected to the support tube 306, and the other end is connected to the top side wall of the annular tube 302. A certain length of the connecting tube 307 is reserved to facilitate the up and down movement with the support tube 306; the annular cavity 308 is opened on the outer wall of the supporting platform 301, and the annular cavity 308 is sealed with the inner wall of the top of the base 2; the vent holes 310 are provided in multiple groups and are opened on the top of the corresponding supporting tube 306, which are used for ventilation and suction; the vent holes 310 are inclined downward, and the inclination angle is toward the upper surface of the top of the supporting platform 301. When the support tube 306 moves upward, air is sucked through the vent holes 310, and when the support tube 306 moves downward, the gas discharged through the vent holes 310 cleans the top surface of the supporting platform 301 to avoid scratches on the epitaxial wafer caused by residual particles, thereby improving the overall quality of the epitaxial wafer.

[0041] The number of the positioning parts 4 is set to be multiple groups, and the multiple groups of positioning parts 4 are adjustably arranged on the top of the base 2. The multiple groups of positioning parts 4 can move synchronously to adjust the epitaxial wafer to a position concentric with the adsorption part 3.

[0042] The rotating posts 401 are arranged in a plurality of groups, and the plurality of groups of rotating posts 401 are rotatably arranged in the top of the base 2;

[0043] The positioning cams 402, whose end close to the epitaxial wafer is made of rubber material to avoid damage to the edge of the epitaxial wafer during rotation, are set in multiple groups and correspond to the rotating column 401, and the bottoms of the multiple positioning cams 402 are fixedly connected to the tops of the multiple rotating columns 401; the driving gears 403, whose number is set in multiple groups, and the tops of the multiple driving gears 403 are fixedly set with the corresponding rotating columns 401; the air flow channels 404, whose number is set in multiple groups, and the multiple air flow channels 404 are opened in the top of the base 2, and the multiple air flow channels 404 are connected to the annular cavity 308; the pushing plates 405, whose number is set in multiple groups and corresponds to the air flow channels 404, are slidably set in the air flow channels 404; the tooth plate 40 6, the number of which is set to multiple groups and corresponds to the push plate 405, and the multiple groups of tooth plates 406 are fixedly set with one end of the corresponding push plate 405, the multiple groups of tooth plates 406 slide in the multiple groups of airflow channels 404, and one end of the multiple groups of tooth plates 406 is meshed with the corresponding driving gear 403, and the gas enters the airflow channel 404 and pushes the push plate 405 and the tooth plate 406 to slide along the airflow channel 404. During the sliding process, the tooth plate 406 drives the driving gear 403, the rotating column 401 and the positioning cam 402 to rotate, so that the positioning cam 402 returns to its initial state; when negative pressure is generated in the airflow channel 404, the negative pressure drives the positioning cam 402 to move toward the carrier 301, so as to realize the positioning of the epitaxial wafer.

[0044] The grinding part 5 is fixedly arranged inside the cabinet 1 and located above the adsorption part 3. When the grinding part 5 cooperates with the adsorption part 3, the adsorption part 3 drives the epitaxial wafer to rotate in the forward direction, and the grinding part 5 starts to rotate in the reverse direction for grinding after contacting the back side of the epitaxial wafer.

[0045] The driving member 501 is electrically connected to the control system. The driving member 501 can be a linear motion mechanism such as an electric telescopic rod and a cylinder, which is convenient for driving the grinding disc 503 to move up and down. It is fixedly arranged inside the cabinet 1 and located above the supporting platform 301. A first driving motor 502 is fixedly arranged at the bottom of the driving member 501 and is electrically connected to the control system; the grinding disc 503 is fixedly arranged at the top with the driving end of the first driving motor 502.

[0046] The protection part 6 is fixedly arranged on the outer wall of the grinding part 5 , and the protection part 6 can move up and down synchronously with the grinding part 5 .

[0047] The protective cover 601 is fixedly disposed on the outer side wall of the bottom of the driving member 501 and is located above the grinding disc 503, and the grinding disc 503 is located inside the protective cover 601, which can prevent the grinding liquid from splashing into the cabinet 1 when grinding the epitaxial wafer.

[0048] It should be noted that a grinding liquid nozzle is provided inside the protective cover 601, and the grinding liquid nozzle is connected to an external grinding liquid supply through a pipeline, so as to spray the grinding liquid when grinding the surface of the epitaxial wafer and improve the surface quality of the epitaxial wafer.

[0049] The liquid discharge portion 7 is opened on the top of the base 2 and is used for discharging liquid.

[0050] The annular chute 701 is opened in the top of the base 2, and the end of the annular chute 701 close to the grinding disc 503 is higher, and the end away from the grinding disc 503 is lower, and the whole is an annular slope; the filter holes 702 are arranged in multiple groups and opened on the top upper surface of the base 2, and the bottoms of the multiple groups of filter holes 702 are connected to the annular chute 701; the drain pipe 703, the top of which is connected to the bottom of the lower end of the annular chute 701, is used to discharge the liquid in the annular chute 701.

[0051] During the grinding process, the epitaxial wafer is sprayed with grinding liquid. Due to the setting of the protective cover 601, most of the grinding liquid splashed inside flows along the filter hole 702 to the annular chute 701. Since the end of the annular chute 701 close to the grinding disc 503 is higher, and the end away from the grinding disc 503 is lower, the whole is an annular slope. The grinding liquid flows from the high point of the annular chute 701 to the low point and is discharged to a designated place outside through the drain pipe 703; and a small part of the liquid will flow out along the inner wall of the protective cover 601. By setting an annular groove (not shown in the figure) below the outflow of the liquid, that is, above the base 2, to collect this part of the liquid, and connecting the pipeline for discharge, it is avoided that the grinding liquid splashes to every corner of the cabinet 1 during grinding, thereby causing corrosion to the inside of the cabinet 1, thereby increasing the service life of the cabinet 1.

[0052] The second driving motor 8 is electrically connected to the control system, and its bottom is fixedly arranged inside the base 2 , and its driving end is fixedly arranged on the bottom of the supporting platform 301 . The second driving motor 8 can drive the supporting platform 301 to rotate.

[0053] In summary, in the initial state, if Figure 7As shown, the top surface of the multiple groups of support cylinders 306 is higher than the top surface of the carrier platform 301. The epitaxial wafer is placed on the top of the support cylinder 306 by a robot or manually held, and then the annular plate 304 is driven downward by the electric telescopic member 305. At the same time, the annular plate 304 drives the T-shaped plate 303 to move downward along the inside of the annular cylinder 302. The T-shaped plate 303 squeezes the gas in the lower part of the annular cylinder 302 during the downward movement. The squeezed gas enters the support cylinder 306 through the connecting pipe 307, and then is sprayed onto the top surface of the carrier platform 301 through the vent hole 310 on the top of the support cylinder 306, so as to clean up the particles and impurities on the top surface of the carrier platform 301, avoid scratches or dents on the side of the epitaxial wafer in contact with the carrier platform 301, and thus improve the surface quality of the epitaxial wafer.

[0054] When the electric telescopic member 305 drives the annular plate 304 and the support cylinder 306 to move downward to the first height, Figure 8 As shown, the top surface of the support tube 306 is flush with the top surface of the carrier platform 301 , and at this time, the bottom surface of the epitaxial wafer above the support tube 306 is in contact with the top surface of the carrier platform 301 .

[0055] While the electric telescopic member 305 moves to the first height, the T-shaped plate 303 draws the gas in the airflow channel 404 back to the upper part of the annular cylinder 302 through the annular cavity 308 and the gas channel 309 during the downward movement. The negative pressure generated in the process of the gas in the airflow channel 404 being drawn back to the annular cavity 308 drives the push plate 405 and the tooth plate 406 to move toward the support platform 301. The tooth plate 406 drives the driving gear 403 and the rotating column 401 to rotate during the movement. The rotating column 401 drives the positioning cam 402 during the rotation, so that the positioning cam 402 pushes the edge of the epitaxial wafer to make it concentric with the support platform 301 during the rotation, and completes the positioning of the epitaxial wafer, thereby improving the overall performance of the epitaxial wafer during the grinding process.

[0056] When the electric telescopic member 305 drives the annular plate 304 to move downward, the annular plate 304 drives the support tube 306 to move downward so that its top surface is lower than the top surface of the carrier 301. At this time, the vent hole 310 is blocked by the carrier 301, and the top of the carrier 301 is no longer cleaned. The support tube 306 can still move downward, so that the support tube 306 reaches the second height, such as Fig. 9 As shown, at this time, a certain gap is generated between the support tube 306 and the epitaxial wafer. The negative pressure generated in the gap sucks the bottom of the epitaxial wafer and fixes the epitaxial wafer on the top surface of the carrier 301, thereby improving the stability of the epitaxial wafer during grinding.

[0057] While the electric telescopic member 305 moves to the second height, the T-shaped plate 303 continues to draw the gas in the airflow channel 404 back to the upper part of the annular cylinder 302 through the annular cavity 308 and the gas channel 309 during the downward movement. The negative pressure generated in the process of the gas in the airflow channel 404 being drawn back to the annular cavity 308 drives the push plate 405 and the tooth plate 406 to move. During the movement, the tooth plate 406 drives the driving gear 403, the rotating column 401 and the positioning cam 402 to rotate, so that the positioning cam 402 breaks away from the contact with the epitaxial wafer, thereby avoiding the positioning cam 402 causing damage to the edge of the epitaxial wafer during the high-speed rotation of the epitaxial wafer, thereby improving the grinding effect of the epitaxial wafer.

[0058] After the epitaxial wafer is fixed on the top surface of the carrier 301, the driving member 501 drives the first driving motor 502 and the grinding disk 503 to move downward to the upper surface of the epitaxial wafer, and then starts the first driving motor 502 and the second driving motor 8 to work, the second driving motor 8 drives the carrier 301 to rotate forward, and the first driving motor 502 drives the grinding disk 503 to rotate reversely and grind the surface of the epitaxial wafer. When the surface flatness treatment of the epitaxial wafer is completed, the electric telescopic member 305 drives the annular plate 304 and the support tube 306 to move upward. At this time, the vent hole 310 is blocked by the carrier 301, and it cannot suck air into the annular tube 302. The support tube 306 can still move upward, so that the support tube 306 moves from the second height to the first height. After moving to the first height, the top of the support tube 306 is flush with the top surface of the carrier 301 and the adsorption and fixation on the bottom of the epitaxial wafer are released.

[0059] While the electric telescopic member 305 drives the annular plate 304 and the T-shaped plate 303 to move from the second height to the first height, the T-shaped plate 303 squeezes the gas on the upper part of the annular cylinder 302, so that the gas enters the air flow channel 404 through the gas channel 309 and the annular cavity 308 and drives the driving gear 403, the rotating column 401 and the positioning cam 402 to rotate, so that the positioning cam 402 contacts the edge of the epitaxial wafer.

[0060] Then the electric telescopic part 305 continues to drive the annular plate 304 to move from the first height to the initial state. At this time, the support tube 306 moves upward under the drive of the annular plate 304, and the vent hole 310 also begins to suck air into the lower part of the annular tube 302 under the action of the T-shaped plate 303; at the same time, the top of the support tube 306 lifts the ground epitaxial wafer upward and supports the bottom of the epitaxial wafer. At this time, there is a distance between the bottom of the epitaxial wafer and the top of the carrier 301, which is convenient for a robot or manual hand to pick it up.

[0061] While the electric telescopic member 305 drives the annular plate 304 and the T-shaped plate 303 to move from the first height to the initial state, the T-shaped plate 303 continues to squeeze the gas on the upper part of the annular cylinder 302, so that the gas enters the air flow channel 404 through the gas channel 309 and the annular cavity 308, and drives the driving gear 403, the rotating column 401 and the positioning cam 402 to rotate, so that the positioning cam 402 does not contact the edge of the epitaxial wafer and returns to the initial state.

[0062] The epitaxial wafer is fixed to the bottom of the carrier 301 by the adsorption part 3 to prevent the epitaxial wafer from shifting during the grinding process, thereby improving the grinding efficiency of the epitaxial wafer; the position of the epitaxial wafer is adjusted by the positioning part 4 before adsorption and fixation to make it concentric with the carrier 301, thereby improving the processing quality and yield rate of the epitaxial wafer.

[0063] Example 2, based on the above example, the grinding liquid after grinding flows into the annular chute 701 through the filter hole 702 and is discharged from the drain pipe 703. However, the grinding liquid after grinding contains grinding particles. When it is discharged through the drain pipe 703 for a long time, the grinding particles cause blockage to the drain pipe 703, resulting in the grinding liquid after grinding cannot be discharged in time, thereby affecting the normal processing of the product; for this reason, the following improvements are made.

[0064] like Figure 5 and Figure 6 As shown, the protective part 6 also includes: a first annular pad 602, which is arranged on the inner wall of the bottom of the protective cover 601; a second annular pad 603, which is arranged on the outer wall of the top of the base 2, and the second annular pad 603 cooperates with the first annular pad 602 to form a seal for the inside of the protective cover 601; during the normal grinding of the epitaxial wafer by the grinding part 5, the first annular pad 602 and the second annular pad 603 are staggered with each other, and at this time, the inside of the protective cover 601 is not in a sealed state.

[0065] When the drain pipe 703 is clogged by abrasive particles in the abrasive liquid during long-term use, the driving member 501 drives the protective cover 601 and the first annular pad 602 to move upward. When the first annular pad 602 moves to be parallel to and in contact with the second annular pad 603, as shown in FIG. Figure 6 As shown, at this time, a sealing state is formed between the protective cover 601 and the base 2, and the grinding disc 503, driven by the driving member 501, has a certain distance from the support cylinder 306 in the initial state and will not hinder the up and down movement of the support cylinder 306.

[0066] Then, in the process that the electric telescopic member 305 drives the annular plate 304 and the T-shaped plate 303 to move downward from the initial position to the first height, the T-shaped plate 303 moves downward along the annular cylinder 302 and squeezes the gas at the lower part of the annular cylinder 302. After being squeezed, the gas is ejected from the venting inclined hole 310 to the inside of the protective cover 601 through the connecting pipe 307 and the supporting cylinder 306, so that the air pressure in the protective cover 601 is increased. The increased air pressure dredges the drain pipe 703. If the drain pipe 703 is not dredged, the electric telescopic member 305 drives the annular plate 304, the T-shaped plate 303 and the supporting cylinder 306 to move downward along the annular cylinder 302 and squeezes the gas at the lower part of the annular cylinder 302. The cylinder 306 moves from the first position to the initial position. During this process, the gas is re-sucked into the lower part of the annular cylinder 302 through the ventilation inclined hole 310. Then the electric telescopic member 305 continues to drive the annular plate 304, the T-shaped plate 303 and the support cylinder 306 to repeat the above operation and move reciprocatingly up and down, driving the support cylinder 306 and the ventilation inclined hole 310 to move from the initial position to the first position, and then from the first position to the initial position, so as to realize reciprocating inflation and suction in the protective cover 601. The air pressure in the protective cover 601 is increased during the reciprocating inflation process to clear the drainage pipe 703.

[0067] Through the cooperation of the first annular pad 602 and the second annular pad 603, a seal is formed between the protective cover 601 and the base 2, and then the adsorption part 3 reciprocates up and down to realize air suction and inflation in the protective cover 601. The increased air pressure in the process of inflating the protective cover 601 is used to clear the drain pipe 703, thereby avoiding overflow of the grinding liquid due to blockage of the drain pipe 703 and ensuring the continuity of epitaxial wafer processing.

[0068] Embodiment 3, the present invention also provides a purification method for an epitaxial wafer back surface flatness processing device, comprising the following steps:

[0069] Step 1: Placement: Place the epitaxial wafer on the top surface of the plurality of support tubes 306 by using a robot or manually holding the epitaxial wafer;

[0070] Step 2: Adsorption: fix the placed epitaxial wafer on the top surface of the carrier 301 through the adsorption unit 3;

[0071] Step 3: Positioning: When the adsorption unit 3 moves the epitaxial wafer downward to the first height, the positioning unit 4 positions the epitaxial wafer so that the epitaxial wafer is concentric with the carrier 301;

[0072] Step 4: Grinding treatment: the grinding unit 5 moves downward and contacts the epitaxial wafer, and then the second driving motor 8 drives the carrier 301 and the epitaxial wafer to rotate in the forward direction, and the grinding unit 5 rotates in the reverse direction to grind the epitaxial wafer;

[0073] Step 5: Unloading: the adsorption unit 3 moves upward to the initial position and removes the epitaxial wafer.

[0074] The embodiments of the present application are described above in conjunction with the accompanying drawings. In the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. An epitaxial wafer back surface flatness processing device, comprising a cabinet (1), characterized in that: Also includes: A base (2) which is fixedly arranged inside the cabinet (1), and the base (2) is a convex structure; The adsorption part (3) is arranged on the top of the base (2), and the adsorption part (3) can adsorb and fix the epitaxial wafer, and can drive the epitaxial wafer to rotate around the top of the base (2); the adsorption part (3) comprises: A supporting platform (301) rotatably disposed on the top of the base (2); An annular cylinder (302) fixedly disposed on the bottom of the base (2); A T-shaped plate (303) which is sealingly slidably disposed in the annular cylinder (302) and is capable of moving up and down along the annular cylinder (302); An annular plate (304) fixedly disposed on the bottom of the T-shaped plate (303); The number of electric telescopic components (305) is set to be multiple groups, and the fixed ends of the multiple groups of electric telescopic components (305) are fixedly arranged at the bottom of the bearing platform (301), and the extended ends of the multiple groups of electric telescopic components (305) are fixedly arranged at the top of the annular plate (304); The support tubes (306) are arranged in a plurality of groups, and the bottoms of the plurality of groups of the support tubes (306) are fixedly arranged on the tops of the annular plates (304), and the tops of the plurality of groups of the support tubes (306) are able to slide up and down in a sealed manner along the bearing platform (301); The connecting tubes (307) are provided in a plurality of groups and correspond to the supporting tubes (306), and one end of the connecting tubes (307) is in communication with the supporting tube (306), and the other end is in communication with the top side wall of the annular tube (302); An annular cavity (308) is formed on the outer wall of the support platform (301), and the annular cavity (308) is sealed from the inner wall of the top of the base (2); Gas channels (309) are arranged in a plurality of groups and are opened inside the support platform (301), and the plurality of groups of gas channels (309) are used to connect the annular cavity (308) with the top of the annular cylinder (302); The ventilation oblique holes (310) are arranged in a plurality of groups and are opened on the top of the corresponding support tube (306) and are used for ventilation and suction; The number of positioning parts (4) is set to be multiple groups, and the multiple groups of positioning parts (4) are adjustably arranged on the top of the base (2), and the multiple groups of positioning parts (4) can be adjusted to a position concentric with the adsorption part (3) by synchronous movement; the positioning parts (4) include: The rotating posts (401) are provided in a plurality of groups, and the plurality of groups of rotating posts (401) are rotatably disposed in the top of the base (2); The positioning cams (402) are arranged in a plurality of groups and correspond to the rotating posts (401), and the bottoms of the plurality of groups of the positioning cams (402) are fixedly connected to the tops of the plurality of groups of the rotating posts (401); The driving gears (403) are provided in a plurality of groups, and the tops of the plurality of groups of the driving gears (403) are fixedly arranged on the corresponding rotating posts (401); The number of airflow channels (404) is set to be multiple groups, and the multiple groups of airflow channels (404) are opened in the top of the base (2), and the multiple groups of airflow channels (404) are connected to the annular cavity (308); Pushing plates (405), which are arranged in a plurality of groups and correspond to the air flow channels (404), and are slidably arranged in the air flow channels (404); The tooth plates (406) are provided in a plurality of groups and correspond to the push plates (405), and the plurality of groups of the tooth plates (406) are fixedly provided on one end of the corresponding push plates (405), the plurality of groups of the tooth plates (406) slide in the plurality of groups of the air flow channels (404), and one end of the plurality of groups of the tooth plates (406) meshes with the corresponding driving gears (403); A grinding part (5) is fixedly arranged inside the cabinet (1) and located above the adsorption part (3), and the grinding part (5) cooperates with the adsorption part (3) to make the adsorption part (3) drive the epitaxial wafer to rotate in the forward direction, and the grinding part (5) starts to rotate in the reverse direction for grinding after contacting the back side of the epitaxial wafer; A protective portion (6) fixedly arranged on the outer wall of the grinding portion (5), and the protective portion (6) is capable of synchronously moving up and down with the grinding portion (5); A liquid discharge portion (7) is opened at the top of the base (2) and is used to discharge liquid.

2. The device for processing flatness of the back side of an epitaxial wafer according to claim 1, characterized in that: The grinding part (5) comprises: A driving member (501) is fixedly arranged inside the cabinet (1) and located above the supporting platform (301), and a first driving motor (502) is fixedly arranged at the bottom of the driving member (501); The top of the grinding disc (503) is fixedly arranged on the driving end of the first driving motor (502).

3. The device for processing flatness of the back side of an epitaxial wafer according to claim 2, characterized in that: The protection part (6) comprises: A protective cover (601) fixedly disposed on the outer side wall of the bottom of the driving member (501) and located above the grinding disc (503); A first annular pad (602) disposed on the inner side wall of the bottom of the protective cover (601); The second annular gasket (603) is arranged on the outer side wall of the top of the base (2), and the second annular gasket (603) cooperates with the first annular gasket (602) to form a seal on the inside of the protective cover (601).

4. The device for processing flatness of the back side of an epitaxial wafer according to claim 3, characterized in that: The liquid discharge part (7) further comprises: An annular inclined groove (701) is formed in the top of the base (2), and the end of the annular inclined groove (701) close to the grinding disc (503) is higher, and the end away from the grinding disc (503) is lower, and the whole is an annular inclined surface; Filter holes (702) are arranged in a plurality of groups and are opened on the top surface of the base (2), and the bottoms of the plurality of groups of filter holes (702) are connected to the annular inclined groove (701); The top of the liquid discharge pipe (703) is connected to the bottom of the lower end of the annular chute (701) and is used to discharge the liquid in the annular chute (701).

5. The device for processing flatness of the back side of an epitaxial wafer according to claim 4, characterized in that: Also includes: The second driving motor (8) has a bottom portion fixedly disposed inside the base (2), and a driving end fixedly disposed on the bottom portion of the supporting platform (301).

6. A method for processing the flatness of the back side of an epitaxial wafer, applied to the device for processing the flatness of the back side of an epitaxial wafer as claimed in claim 5, characterized in that: The following steps are involved: Step 1: placing, using a robot or manually holding the epitaxial wafer on the top surface of the plurality of support tubes (306); Step 2: adsorption, fixing the placed epitaxial wafer on the top surface of the carrier platform (301) through the adsorption part (3); Step three, positioning, when the adsorption unit (3) moves the epitaxial wafer downward to a first height, the positioning unit (4) positions the epitaxial wafer so that the epitaxial wafer and the carrier platform (301) are in a concentric position; Step 4: grinding, the grinding unit (5) moves downward and contacts the epitaxial wafer, then the second drive motor (8) drives the carrier (301) and the epitaxial wafer to rotate in a forward direction, and the grinding unit (5) rotates in a reverse direction to grind the epitaxial wafer; Step 5: Unloading: Move the adsorption part (3) upward to the initial position and remove the epitaxial wafer.

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