Wafer surface polishing apparatus and polishing method thereof

Abstract

The application relates to the technical field of wafer processing, in particular to a wafer surface polishing device and a polishing method thereof, which solve the problem that high polishing precision and high polishing efficiency cannot be simultaneously achieved in wafer surface polishing. The polishing device comprises a workbench, a rotating table, a plurality of polishing pieces, an adjusting assembly, a visual recognition piece and a control piece. The adjusting assembly is configured to make at least one polishing piece approach or move away from the surface to be polished in the vertical direction, and make at least one polishing piece approach or move away from the origin in the horizontal direction. The control piece determines polishing data according to the identified image, and controls the adjusting assembly to drive at least one polishing piece to move according to the polishing data, so that a protrusion in a preset area is polished by one polishing piece when the rotating table is stationary, or at least one protrusion is simultaneously polished by a plurality of polishing pieces when the rotating table rotates. The wafer surface polishing device and the polishing method thereof provided by the application can improve the precision and polishing efficiency of wafer surface polishing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wafer processing, and particularly relates to a wafer surface polishing device and a polishing method thereof. BACKGROUND

[0002] The wafer prepared by taking silicon carbide as a main material is widely applied to the fields of semiconductors, electronics, machinery, chemical industry, aerospace, etc., and the material on the wafer surface is applied to the electronic industry due to the properties of high temperature resistance, wear resistance, corrosion resistance, high heat conduction, high insulation, etc., such as being used for ultra-large scale integrated circuit substrates. The quality of the wafer surface has an important influence on the performance and service life of the wafer, and there is a polishing process for the wafer surface in the preparation process of the wafer. However, with the improvement of the quality requirement and production capacity of the wafer surface, the current polishing for the wafer surface cannot simultaneously meet the requirements of high polishing precision and high polishing efficiency. SUMMARY

[0003] In view of this, the present application provides a wafer surface polishing device and a polishing method thereof, which solves the problem that the polishing for the wafer surface cannot simultaneously meet the requirements of high polishing precision and high polishing efficiency.

[0004] The application provides a wafer surface polishing device, comprising: a workbench; a rotary table rotatably connected to the workbench, the rotary table being configured to carry a wafer, the wafer having a surface to be polished, the rotary table having a first axis, the rotary table being configured to rotate the wafer around the first axis, the surface to be polished of the wafer carried by the rotary table being divided into a plurality of annular preset regions in a nested manner with a point coinciding with the first axis as an origin, at least one of the preset regions having at least one protrusion; a plurality of polishing members movably connected to the workbench, the polishing members being configured to polish the protrusions; an adjusting assembly arranged on the workbench, the polishing members being connected to the adjusting assembly, the adjusting assembly being configured to make at least one of the polishing members approach or move away from the surface to be polished in a vertical direction, and make at least one of the polishing members move in a horizontal direction to approach or move away from the origin; a visual recognition member arranged on the workbench, the visual recognition member being configured to sequentially scan each of the preset regions from the origin to the edge of the wafer, and form a recognition image according to the recognized protrusions in the scanned preset region; and a control member in communication connection with the visual recognition member, the adjusting assembly and the rotary table, the control member being configured to determine polishing data according to the recognition image, and control the adjusting assembly to move at least one of the polishing members according to the polishing data, so that one of the protrusions of the preset regions is polished to be flush with the surface to be polished by one of the polishing members when the rotary table is stationary, or at least one of the protrusions is simultaneously polished to be flush with the surface to be polished by a plurality of the polishing members when the rotary table rotates.

[0005] According to the wafer surface polishing device provided by the application, the control member comprises:

[0006] The controller is in communication connection with the visual recognition member, the adjusting assembly and the rotary table; a processor is in communication connection with the controller, the processor being configured to receive the recognition image, and acquire at least the height of each of the protrusions in the preset region protruding from the surface to be polished and compare the height with a preset height according to the recognition image, so that the protrusions lower than or equal to the preset height are simultaneously polished by a plurality of the polishing members, and each of the protrusions higher than the preset height is polished by one of the polishing members.

[0007] According to the wafer surface polishing device provided by the application, the preset height is between 0.2 mm and 0.3 mm.

[0008] According to the wafer surface polishing device provided in the application, the adjusting assembly comprises: a carrier plate located above the workbench; a first driving assembly connected between the carrier plate and the workbench, configured to drive the carrier plate to move towards or away from the workbench in the vertical direction, and the first driving assembly is in communication connection with the control element; a plurality of adjusting blocks movably connected to the carrier plate, and the plurality of adjusting blocks are arranged in a ring shape around the first axis, and each adjusting block is connected with a polishing element; and at least one second driving assembly connected to the carrier plate, each adjusting block being connected with a second driving assembly, and the second driving assembly is configured to drive the adjusting block to move towards or away from the first axis, and each second driving assembly is in communication connection with the control element.

[0009] According to the wafer surface polishing device provided in the application, the visual recognition element is arranged on the side of the carrier plate facing the workbench, and the geometric center of the recognition part of the visual recognition element coincides with the projection of the first axis on the turntable.

[0010] According to the wafer surface polishing device provided in the application, the clamping positioning element is connected to the turntable, and the clamping positioning element is configured to limit the wafer carried by the turntable.

[0011] According to the wafer surface polishing device provided in the application, the clamping positioning element comprises: a carrier connected to the turntable, the center of the carrier coincides with the first axis, the carrier is provided with a plurality of adsorption holes in communication with an external vacuum pump, and the adsorption holes are configured to adsorb the wafer on the carrier; and a plurality of clamping blocks slidably connected to the carrier, the plurality of clamping blocks are arranged in a ring shape around the first axis, and each clamping block can move towards or away from the first axis.

[0012] According to the wafer surface polishing device provided in the application, any adjacent preset regions are not overlapped or partially overlapped.

[0013] In a second aspect, the application also provides a wafer surface polishing method applied to the wafer surface polishing device described above. The surface to be polished of the wafer takes a point coinciding with the first axis of the rotary table of the wafer surface polishing device as the origin. The wafer surface polishing method comprises: identifying the surface to be polished by the visual recognition member, and dividing the surface to be polished into a plurality of nested preset areas with the origin as the center; sequentially scanning each of the preset areas from the origin to the edge of the wafer by the visual recognition member. If at least one protrusion is identified in the scanned preset area, an identification image is generated, otherwise the next preset area is continuously scanned; the controller receives the identification image and processes the identification image to obtain polishing data, and controls the adjusting assembly to drive at least one polishing member to move in the vertical direction and / or the horizontal direction according to the polishing data, so that one protrusion of the preset area is polished to be flush with the surface to be polished by one polishing member when the rotary table is stationary, or at least one protrusion is simultaneously polished to be flush with the surface to be polished by a plurality of polishing members when the rotary table rotates.

[0014] According to the wafer surface polishing method provided by the application, the controller comprises a controller and a processor in communication with each other. The controller receives the identification image from the visual recognition member and sends the identification image to the processor. The processor receives the identification image and identifies the position of each protrusion in the preset area relative to the origin, the size of the protrusion, and compares the height of each protrusion protruding from the surface to be polished with a preset height according to the identification image, to obtain the polishing data, and sends the polishing data to the controller. The controller controls the adjusting assembly to act according to the polishing data, so that the protrusions lower than or equal to the preset height are simultaneously polished to be flush with the surface to be polished by a plurality of polishing members, and each protrusion higher than the preset height is polished to be flush with the surface to be polished by one polishing member.

[0015] The wafer surface polishing device provided by the application divides the surface to be polished of the wafer carried on the rotating table into a plurality of annular preset regions, uses a visual recognition element to sequentially recognize each preset region from the edge of the wafer with the original point as the center, forms an identification image if a protrusion is recognized, and controls the action of the rotating table and the adjusting assembly according to the protrusion in the identification image, so that a larger protrusion is polished by one polishing element, and a plurality of smaller protrusions are simultaneously polished by a plurality of polishing elements. This way of using a visual recognition element to perform regional recognition to polish different protrusions not only avoids the situation of missing polishing due to the naked eye failing to recognize the protrusion, but also makes all the protrusions on the wafer surface be recognized by the high-precision recognition of the visual recognition element, so that different degrees of protrusions can be matched with different degrees of polishing, which is beneficial to improve the polishing precision and speed of the protrusions, reduce the polishing error, and further improve the polishing precision and speed of the wafer surface, thereby improving the productivity of the wafer.

[0016] In addition, the surface to be polished of the wafer is divided into a plurality of preset regions, and each preset region is sequentially scanned by a visual recognition element, and an identification image is formed when a protrusion is scanned in the preset region for subsequent polishing work, and the next image is continuously scanned when no protrusion is recognized, so that the polishing element is operated to polish the preset region with the protrusion, which further improves the polishing speed.

[0017] In addition, the rotating table is set to be selected to rotate or be stationary according to the specific situation of the protrusion to be polished. When a single polishing element polishes a larger protrusion, the control element makes the rotating table stationary, and when a plurality of smaller protrusions are simultaneously polished by a plurality of polishing elements, the control element controls the rotating table to rotate, which further improves the polishing speed. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 Fig. 1 is a schematic diagram of a wafer surface polishing device provided by the application.

[0019] Figure 2 Fig. 2 is a schematic diagram of the surface to be polished of a wafer provided by the application.

[0020] Figure 3 Fig. 3 is a schematic diagram of a preset region in the surface to be polished of a wafer provided by the application.

[0021] Figure 4 Fig. 4 is a schematic diagram of a partial structure of a wafer surface polishing device provided by the application.

[0022] Figure 5 Fig. 5 is a schematic diagram of a partial structure of a wafer surface polishing device provided by the application. Figure 4 Fig. 6 is a sectional view of a partial structure of a wafer surface polishing device provided by the application.

[0023] Figure 6 Fig. 1 shows a schematic diagram of a wafer surface polishing device provided by the present application.

[0024] Figure 7 Fig. 2 shows a flow chart of a wafer surface polishing method provided by the present application.

[0025] Figure 8 Fig. 3 shows a flow chart of another wafer surface polishing method provided by the present application.

[0026] Reference signs:

[0027] 1, workbench; 2, turntable; 2a, first axis; 21, driving motor; 3, polishing piece; 31, polishing head; 32, driving part; 4, adjusting assembly; 41, first driving assembly; 42, carrier plate; 43, adjusting block; 44, second driving assembly; 441, motor; 442, screw-nut pair; 5, clamping positioning piece; 51, carrier; 51a, adsorption hole; 511, sliding groove; 52, clamping block; 6, wafer; 61, surface to be polished; 611, preset area; 611a, annular area; 612, protrusion; 6a, origin; 7, visual recognition piece. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0029] The present application provides a wafer surface polishing device, such as Figures 1 to 4 The wafer surface polishing device is used for polishing the surface to be polished 61 of the wafer 6. It can be understood that the surface to be polished 61 can be the surface of the wafer 6 used for integrated circuits, and the surface to be polished 61 can be the surface of at least one side of the wafer 6 in the thickness direction.

[0030] Optionally, the material of the wafer 6 can be graphite, silicon carbide, etc., the shape of the wafer 6 can be circular, oval, square, polygonal, etc., and the size of the wafer 6 can also be adjusted according to actual polishing requirements, which is not specifically limited.

[0031] Specifically, the wafer surface polishing device comprises a workbench 1, a turntable 2, a plurality of polishing pieces 3 and an adjusting assembly 4, a visual recognition piece 7 and a control piece. The turntable 2 is rotationally connected to the workbench 1. The turntable 2 is configured to carry a wafer 6. The turntable 2 has a first axis 2a. The turntable 2 is configured to rotate the wafer 6 around the first axis 2a. A surface 61 to be polished of the wafer 6 carried by the turntable 2 is divided into a plurality of annular preset regions 611 in a sleeve connection mode with a point coinciding with the first axis 2a as an origin 6a. At least one preset region 611 has at least one protrusion 612. The plurality of polishing pieces 3 are movably connected to the workbench 1. The polishing pieces 3 are configured to polish the protrusions 612. The adjusting assembly 4 is arranged on the workbench 1. The plurality of polishing pieces 3 are connected to the adjusting assembly 4. The adjusting assembly 4 is configured to make at least one polishing piece 3 approach or move away from the surface 61 to be polished in a vertical direction, and make at least one polishing piece 3 move in a horizontal direction to approach or move away from the origin 6a. The visual recognition piece 7 is arranged on the workbench 1. The visual recognition piece 7 is configured to sequentially scan each preset region 611 from the origin 6a to the edge of the wafer 6, and form a recognition image according to the recognized protrusions 612 in the scanned preset region 611. The control piece is in communication connection with the visual recognition piece 7, the adjusting assembly 4 and the turntable 2. The control piece determines polishing data according to the recognition image, and controls the adjusting assembly 4 to drive at least one polishing piece 3 to move according to the polishing data, so that one protrusion 612 of the preset region 611 is polished to be flush with the surface 61 to be polished by one polishing piece 3 when the turntable 2 is stationary, or at least one protrusion 612 is simultaneously polished to be flush with the surface 61 to be polished by a plurality of polishing pieces 3 when the turntable 2 rotates.

[0032] Optionally, the visual recognition piece 7 can be a camera, and specifically can comprise a recognition part and a gimbal. The recognition part is used for imaging the surface 61 to be polished. The recognition part is detachably connected to the workbench 1 through the gimbal. In other embodiments, the visual recognition piece 7 can also be other devices capable of imaging, without specific limitation.

[0033] Optionally, the turntable 2 is connected with a driving motor 21. The driving motor 21 is in communication connection with the control piece. The control piece can control the driving motor 21 to start or stop, so as to drive the turntable 2 to rotate or stop rotating around the first axis 2a.

[0034] In the embodiment of the present application, the surface 61 to be polished of the wafer 6 carried on the turntable 2 is divided into a plurality of annular preset regions 611 which are nested, the visual recognition member 7 is used to sequentially recognize each preset region 611 from the edge of the wafer 6 with the origin 6a as the center, and if a protrusion 612 is recognized, an identification image is formed, and the controller controls the actions of the turntable 2 and the adjusting assembly 4 according to the situation of the protrusion 612 in the identification image, so that a protrusion 612 with a larger size is subjected to targeted polishing by one polishing member 3, and a plurality of protrusions 612 with a smaller size and located in the same preset region 611 can be simultaneously polished by a plurality of polishing members 3. This way of using the visual recognition member 7 to perform regional recognition for targeted polishing of different protrusions 612 not only avoids the situation of missing polishing due to the fact that the protrusions 612 cannot be recognized by the naked eye, but also enables all protrusions 612 on the surface of the wafer 6 to be recognized by the high-precision recognition of the visual recognition member 7, so that different degrees of protrusions 612 can be matched with different degrees of polishing, which is beneficial to improving the polishing precision and speed of the protrusions 612, reducing the polishing error, and further improving the polishing precision and speed of the surface of the wafer 6, thereby improving the production capacity of the wafer 6.

[0035] Moreover, the surface 61 to be polished of the wafer 6 is divided into a plurality of preset regions 611, and each preset region 611 is sequentially scanned by the visual recognition member 7, and when a protrusion 612 is scanned in the preset region 611, an identification image is formed for subsequent polishing work, and when no protrusion 612 is recognized, the next image is continuously scanned, so that the polishing member 3 is only used for targeted polishing of the preset region 611 with the protrusion 612, further improving the polishing speed.

[0036] In addition, the turntable 2 is arranged to be selected to rotate or be stationary according to the specific situation of the protrusion 612 to be polished, when a single polishing member 3 is used to polish a protrusion 612 with a larger size, the controller makes the turntable 2 stationary, and when a plurality of polishing members 3 are used to simultaneously polish protrusions 612 with a smaller size, the controller controls the turntable 2 to rotate, further improving the polishing speed.

[0037] It can be understood that the protrusions 612 to be polished recognized by the visual recognition member 7 can be burrs, local protruding surface oxidation layers and other defects, which are not specifically limited. In order to facilitate observation, Figure 2 and Figure 3 The circles with black shadows and the circles without black shadows in the above-mentioned schematic diagram represent the protrusions 612, and the dashed lines represent the edges of the divided preset regions 611.

[0038] In an optional embodiment, the polishing member 3 can include a connected driving part 32 and a polishing head 31, the driving part 32 is in communication connection with the control member, the driving part 32 is capable of driving the polishing head 31 to rotate around its own axis, and the axis of the polishing head 31 is parallel to the first axis 2a. And the polishing head 31 is provided with a polishing surface on the side facing the turntable 2, the polishing surface is used to contact the protrusions 612 to be polished in the surface 61 to be polished and to realize the polishing of the protrusions 612 through the rotation of the polishing head 31.

[0039] It can be understood that the polishing surface of the polishing head 31 can be a plane or an arc surface, and the size and shape of the polishing surface can be adaptively adjusted according to actual polishing requirements. In this application, the polishing surface can be provided as a circular plane, and the diameter of the circle can be adaptively adjusted according to actual requirements, without specific limitation.

[0040] Optionally, the number of the plurality of preset regions 611 divided by the wafer 6 and the area of each preset region 611 can be adaptively adjusted according to the actual size of the wafer 6 carried by the turntable 2. And the division of the plurality of preset regions 611 of the wafer 6 can be realized by the visual recognition member 7, for example, after the wafer 6 is loaded onto the turntable 2, the visual recognition member 7 can first identify the area of the surface of the wafer 6 as a whole, divide the radius from the origin 6a to the edge of the wafer 6 into N equal parts, and form a plurality of preset regions 611 after each equal part is made into a circle.

[0041] Optionally, among the plurality of preset regions 611 divided, there is no overlap between any adjacent preset regions 611, so as to avoid repeated scanning. Alternatively, the adjacent preset regions 611 can be partially overlapped to avoid the protrusions 612 at the edge position of the preset region 611 from being easily missed.

[0042] In some embodiments, the control member includes a controller and a processor, the controller is in communication connection with the visual recognition member 7, the adjusting assembly 4 and the turntable 2; the processor is in communication connection with the controller, the processor is configured to receive the identification image, and at least obtain the height of each protrusion 612 protruding from the surface 61 to be polished in the preset region 611 and compare it with the preset height according to the identification image, so that the protrusions 612 lower than or equal to the preset height are simultaneously polished by the plurality of polishing members 3, and each protrusion 612 higher than the preset height is polished by one polishing member 3.

[0043] It can be understood that the preset height is taken as a reference height pre-input into the processor, and all the protrusions 612 in the preset area 611 are classified by height, all the protrusions 612 higher than the preset height are taken as a first group (illustrated as circles without black shading in the figure), and the protrusions 612 lower than or equal to the preset height are taken as a second group (illustrated as circles with black shading in the figure), and the processor calculates the size, height, distance to the origin 6a and other related data of the protrusions 612 in each group to form polishing data.

[0044] Optionally, the preset height is between 0.2 mm and 0.3 mm. For example, the preset height can be 0.2 mm, 0.25 mm or 0.3 mm. In the embodiment of the present application, the preset height is set to 0.3 mm, which can be adjusted adaptively according to actual needs.

[0045] For example, as shown in FIG. 6, the protrusions 612 in the preset area 611 are classified by height, and the protrusions 612 higher than the preset height are taken as a first group (illustrated as circles without black shading in the figure), and the protrusions 612 lower than or equal to the preset height are taken as a second group (illustrated as circles with black shading in the figure). Figure 3 In the identification image formed by one preset area 611, a total of 9 protrusions 612 are identified, the processor calculates the height, size, distance to the origin 6a of the 9 protrusions 612 according to the identification image, compares the height of the 9 protrusions 612 with the preset height 0.3 mm respectively, divides 2 protrusions 612 higher than the preset height into a first group, and divides other protrusions 612 lower than or equal to the preset height into a second group, and calculates the related data of the protrusions 612 in each group to obtain polishing data and send the polishing data to the controller. Then, the controller polishes the protrusions 612 in the first group with a large height difference by using one polishing piece 3 to polish one protrusion 612 in a one-to-one manner, and polishes the protrusions 612 in the second group with a small height difference by using multiple polishing pieces 3 to polish simultaneously.

[0046] Optionally, when polishing the protrusions 612 in the first group, the controller can control the multiple polishing heads 31 to move to positions corresponding to different protrusions 612 respectively, so that the multiple polishing heads 31 polish the multiple protrusions 612 in the first group respectively, to improve the polishing speed.

[0047] In addition, before polishing the protrusions 612 in the second group, the processor can further divide the multiple protrusions 612 in the second group according to the diameter of the polishing head 31 and the distance of the multiple protrusions 612 in the second group to the origin 6a. In the case that the distances of the multiple polishing heads 31 to the origin 6a are the same, the polishing surface of the turntable 2 faces the projection direction of the turntable 2 to form a ring-shaped area 611a when the turntable 2 rotates, so that the preset area 611 can be further divided into at least one ring-shaped area 611a, and the multiple polishing heads 31 are used to polish multiple protrusions 612 in the same ring-shaped area 611a simultaneously.

[0048] Optionally, the protrusions 612 in the plurality of annular regions 611a can be polished in sequence from the center of the original point 6a to the edge of the wafer 6 to avoid the situation of missing polishing.

[0049] In an optional embodiment, when polishing the plurality of protrusions 612 in the same annular region 611a, the processor can first calculate the height of each protrusion 612 in the annular region 611a, and adjust the distance of the plurality of polishing heads 31 in the vertical direction to the surface 61 to be polished according to the lowest protrusion 612 to ensure the polishing accuracy of the plurality of protrusions 612 in the annular region 611a.

[0050] In an optional embodiment, before polishing the plurality of protrusions 612 in the same annular region 611a, when the annular region 611a is identified to include the first group of protrusions 612, the controller can control the polishing member 3 to first perform targeted polishing on the first group of protrusions 612 to be lower than or equal to the preset height, and then control the plurality of polishing heads 31 to polish all the protrusions 612 in the annular region 611a at the same time, so as to avoid the risk that the protrusions 612 and the surface 61 to be polished are in contact with each other and are prone to irregular fracture when the plurality of polishing heads 31 polish the protrusions 612 with higher height.

[0051] Optionally, when the polishing heads 31 first polish the first group of protrusions 612, the first group of protrusions 612 can be polished to be flush with the surface 61 to be polished, or can be polished to be lower than or equal to the preset height, which can be adjusted adaptively according to actual needs, and is not limited specifically.

[0052] It can be understood that the processor can include an edge calculator, which can be used for calculating and analyzing data such as the height, size and distance to the original point 6a of the protrusions 612 in the identified image, so as to obtain the polishing height, polishing area and polishing time of the polishing member 3 for different protrusions 612.

[0053] Optionally, when the visual recognition member 7 completes the scanning of each preset region 611, it means that the first polishing of the surface 61 to be polished is completed. The visual recognition member 7 further includes sequentially performing the second scanning on each preset region 611 from the center of the original point 6a to the edge of the wafer 6, repeating the above operation until each preset region 611 can no longer identify the protrusions 612.

[0054] In some embodiments, as Figure 4 and Figure 5The adjusting assembly 4 comprises a carrier plate 42, a first driving assembly 41, a plurality of adjusting blocks 43, and at least one second driving member. The carrier plate 42 is located above the worktable 1. The first driving assembly 41 is connected between the carrier plate 42 and the worktable 1, and is configured to drive the carrier plate 42 to move towards or away from the worktable 1 in the vertical direction. The first driving assembly 41 is in communication connection with the controller. The adjusting blocks 43 are movably connected to the carrier plate 42, and are arranged in a ring shape around the first axis 2a. Each adjusting block 43 is connected to a polishing member 3. The second driving assembly 44 is connected to the carrier plate 42, and each adjusting block 43 is connected to a second driving assembly 44. The second driving assembly 44 is configured to drive the adjusting block 43 to move towards or away from the first axis 2a. Each second driving assembly 44 is in communication connection with the controller. The movement of one or more polishing heads 31 in the vertical direction and the movement of one or more polishing heads 31 towards or away from the origin 6a in the horizontal direction are adjusted according to the situation of the protrusions 612 to be polished, so that one protrusion 612 can be polished or multiple protrusions 612 can be polished at the same time according to the requirements, and the operation is facilitated.

[0055] It can be understood that the first driving assembly 41 can comprise a driving cylinder and a guide member. The driving cylinder is arranged on the worktable 1, and is in communication connection with the controller. The top rod of the driving cylinder extends in the vertical direction and is connected to the carrier plate 42. The guide member comprises a guide shaft and a guide sleeve which are matched in the vertical direction. One of the guide shaft and the guide sleeve is arranged on the worktable 1, and the other is arranged on the carrier plate 42. The movement of the top rod in the vertical direction driven by the driving cylinder can drive the carrier plate 42 to move towards or away from the worktable 1 in the vertical direction.

[0056] Optionally, the second driving assembly 44 comprises a motor 441 and a connected screw-nut pair 442. The motor 441 is in communication connection with the controller. The screw-nut pair 442 comprises a screw rod connected to the output end of the motor 441, and a nut threadedly connected to the screw rod. The adjusting block 43 is fixedly connected to the nut. The motor 441 can drive the screw rod to rotate, thereby driving the nut to move along the axis of the screw rod, so that the distance from each adjusting block 43 to the origin 6a is individually adjustable.

[0057] Optionally, the visual recognition member 7 is arranged on the side of the carrier plate 42 facing the worktable 1, and the geometric center of the recognition part of the visual recognition member 7 coincides with the projection of the turntable 2 and the projection of the first axis 2a on the turntable 2, so as to improve the accuracy and stability of the identification of the surface 61 to be polished of the wafer 6.

[0058] In some embodiments, as Figure 6The wafer surface polishing device further comprises a clamping positioning member 5 connected to the rotary table 2, which is configured to position the wafer 6 carried by the rotary table 2, so as to ensure that the wafer 6 can rotate smoothly with the rotary table 2 when the plurality of protrusions 612 are polished at the same time, and avoid the wafer 6 from deviating during rotation.

[0059] Specifically, the clamping positioning member 5 comprises a carrier 51 and a plurality of clamping blocks 52, the carrier 51 is connected to the rotary table 2, the center of the carrier 51 coincides with the first axis 2a, the carrier 51 is provided with a plurality of adsorption holes 51a in communication with an external vacuum pump, the adsorption holes 51a are configured to adsorb the wafer 6 on the carrier 51; the carrier 51 is provided with a plurality of sliding grooves 511, the clamping blocks 52 are slidingly connected to the sliding grooves 511 of the carrier 51, the plurality of clamping blocks 52 are arranged in a ring shape around the first axis 2a, and each clamping block 52 can move towards or away from the first axis 2a. The combination of adsorption positioning by the adsorption holes 51a and clamping positioning by the clamping blocks 52 can ensure the stability of clamping while exposing the entire surface 61 to be polished of the wafer 6, and can be suitable for clamping and fixing wafers 6 of different shapes, sizes and thicknesses, and can be suitable for clamping and positioning different wafers 6.

[0060] The wafer surface polishing device further comprises a clamping positioning member 5 connected to the rotary table 2, which is configured to position the wafer 6 carried by the rotary table 2, so as to ensure that the wafer 6 can rotate smoothly with the rotary table 2 when the plurality of protrusions 612 are polished at the same time, and avoid the wafer 6 from deviating during rotation. Figure 7 and Figure 8 The wafer surface polishing method comprises the following steps:

[0061] S81, identifying the surface 61 to be polished by the visual recognition member 7, and dividing the surface 61 to be polished into a plurality of pre-set regions 611 centered on the origin 6a.

[0062] It can be understood that the division of the pre-set regions 611 in the surface 61 to be polished can refer to the related description of the wafer surface polishing device described above, and will not be repeated here.

[0063] S82, sequentially scanning each pre-set region 611 from the origin 6a to the edge of the wafer 6 by the visual recognition member 7, if at least one protrusion 612 is identified in the scanned pre-set region 611, an identification image is generated, otherwise the next pre-set region 611 is continuously scanned.

[0064] It can be understood that the visual recognition member 7 can identify protrusions 612 that cannot be identified by the naked eye in the surface 61 to be polished, improving the identification accuracy and precision.

[0065] S83, the control member receives the identification image and processes the identification image to obtain polishing data, and controls the adjusting assembly 4 to drive the at least one polishing member 3 to move in the vertical direction and / or the horizontal direction according to the polishing data, so that a protrusion 612 of the preset area 611 is polished to be flush with the surface 61 to be polished by one polishing member 3 when the turntable 2 is stationary, or at least one protrusion 612 is simultaneously polished to be flush with the surface 61 to be polished by multiple polishing members 3 when the turntable 2 rotates.

[0066] The wafer polishing method provided by the embodiment of the application uses the visual identification member 7 to sequentially identify each preset area 611 from the edge of the wafer 6 to the origin 6a, and forms an identification image if a protrusion 612 is identified. The controller controls the actions of the turntable 2 and the adjusting assembly 4 according to the situation of the protrusion 612 in the identification image, so that a protrusion 612 with a larger size is subjected to targeted polishing by one polishing member 3, and multiple protrusions 612 with smaller sizes and located in the same annular area 611a can be simultaneously polished by multiple polishing members 3. This way of using the visual identification member 7 to perform regional identification to perform targeted polishing on different protrusions 612 can match different polishing methods for different protrusions 612, so as to realize small-area targeted polishing on protrusions 612 in different positions, which is beneficial to improve the polishing precision and polishing speed of the surface 61 to be polished and reduce the polishing error.

[0067] In an optional embodiment, the step S83 specifically includes:

[0068] S831, the controller receives the identification image from the visual identification member 7 and sends the identification image to the processor.

[0069] S832, the processor receives the identification image and identifies the position of each protrusion 612 in the preset area 611 relative to the origin 6a, the size of the protrusion 612, and the height of each protrusion 612 protruding from the surface 61 to be polished relative to the preset height according to the identification image, obtains polishing data, and sends the polishing data to the controller.

[0070] S833, the controller controls the adjusting assembly 4 to act according to the polishing data, so that the protrusions 612 lower than or equal to the preset height are simultaneously polished to be flush with the surface 61 to be polished by multiple polishing members 3, and each protrusion 612 higher than the preset height is polished to be flush with the surface 61 to be polished by one polishing member 3.

[0071] It can be understood that, before the polishing data is sent to the controller, all the protrusions 612 in the preset area 611 can be classified according to the result of comparison between the height of each protrusion 612 protruding from the surface 61 to be polished and the preset height, the protrusions 612 higher than the preset height are taken as a first group, and the protrusions 612 lower than or equal to the preset height are taken as a second group, the preset area 611 is further divided into at least one annular area 611a, and it is identified in sequence whether the protrusions 612 in each annular area 611a only include the protrusions 612 of the second group, if yes, the plurality of polishing heads 31 simultaneously polish the plurality of protrusions 612, otherwise, one polishing head 31 polishes the protrusions 612 of the first group first, and then the plurality of polishing heads 31 simultaneously polish the protrusions 612 in the annular area 611a, and specific reference can be made to the related description in the above embodiments, which will not be described herein.

[0072] In the description, "one embodiment", "an embodiment", or the like means that the described embodiment can include a particular feature, structure, or characteristic, but every embodiment can not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Furthermore, in describing features, structures, or characteristics of one embodiment, the description is sufficient to enable one of ordinary skill in the art to practice such features, structures, or characteristics in one of the other embodiments without undue experimentation.

[0073] It should be understood that "on", "above", and "upper" in the disclosure should be interpreted in the broadest possible way, so that "on" means not only "directly on", but also includes the meaning of "on" with intermediate features or layers therebetween, and "above" or "upper" includes not only the meaning of "above" or "upper", but also the meaning of "above" or "upper" without intermediate features or layers therebetween (i.e., directly on).

[0074] In addition, spatial relative terms, such as "below", "under", "lower", "above", "on", or the like, can be used herein for ease of description to describe one component or feature's relationship to another component or feature as illustrated in the figures. The spatial relative terms are intended to encompass different orientations of the components in use or operation in addition to the orientations depicted in the figures. The devices can have other orientations (rotated 90 degrees or otherwise oriented), and the spatial relative descriptors used herein can be interpreted accordingly.

[0075] It should be noted that, in the present application, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises a", "comprising", or "comprises" does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0076] The above description is merely illustrative of the application, and not in limitation thereof. It will thus be understood that numerous modifications and changes in the details of the embodiments disclosed herein are possible without departing from the spirit and the scope of the application, which is defined by the following claims.

Claims

1. A wafer surface polishing apparatus characterized by comprising: The application relates to a polishing device for polishing a wafer, comprising: a workbench; a rotary table rotatably connected to the workbench, the rotary table being configured to carry the wafer, the wafer having a surface to be polished, the rotary table having a first axis, the rotary table being configured to rotate the wafer around the first axis, the surface to be polished of the wafer carried by the rotary table being divided into a plurality of annular preset regions in a nested manner with a point coinciding with the first axis as an origin, at least one of the preset regions having at least one protrusion; a plurality of polishing elements movably connected to the workbench, the polishing elements being configured to polish the protrusions; an adjusting assembly arranged on the workbench, a plurality of the polishing elements being connected to the adjusting assembly, the adjusting assembly being configured to move at least one of the polishing elements in a vertical direction to approach or move away from the surface to be polished and move at least one of the polishing elements in a horizontal direction to approach or move away from the origin; a visual recognition element arranged on the workbench, the visual recognition element being configured to sequentially scan each of the preset regions from the origin to the edge of the wafer and form a recognition image according to the recognized protrusions in the scanned preset region; a control element in communication connection with the visual recognition element, the adjusting assembly and the rotary table, the control element being configured to determine polishing data according to the recognition image and control the adjusting assembly to move at least one of the polishing elements according to the polishing data so that one of the protrusions of the preset regions is polished to be flush with the surface to be polished by one of the polishing elements when the rotary table is stationary or at least one of the protrusions is simultaneously polished to be flush with the surface to be polished by a plurality of the polishing elements when the rotary table rotates; wherein the control element comprises: a controller in communication connection with the visual recognition element, the adjusting assembly and the rotary table; a processor in communication connection with the controller, the processor being configured to receive the recognition image, recognize the position of each of the protrusions in the preset region relative to the origin, the size of the protrusions and the height of each of the protrusions protruding from the surface to be polished and compared with a preset height according to the recognition image, obtain the polishing data and send the polishing data to the controller, the controller controlling the adjusting assembly to act according to the polishing data so that the protrusions lower than or equal to the preset height are simultaneously polished to be flush with the surface to be polished by a plurality of the polishing elements and each of the protrusions higher than the preset height is polished to be flush with the surface to be polished by one of the polishing elements.

2. The wafer surface polishing apparatus according to claim 1, wherein The preset height is between 0.2 mm and 0.3 mm.

3. The wafer surface polishing apparatus of claim 1, wherein The adjusting assembly comprises: a carrier plate located above the workbench; a first driving assembly connected between the carrier plate and the workbench, the first driving assembly being configured to drive the carrier plate to approach or move away from the workbench in a vertical direction, the first driving assembly being in communication connection with the control element; a plurality of adjusting blocks movably connected to the carrier plate, the adjusting blocks being arranged in a ring shape around the first axis, each of the adjusting blocks being connected with one of the polishing elements. At least one second driving assembly is connected to the carrier plate, each of the adjusting blocks is connected to one of the second driving assemblies, and the second driving assemblies are configured to drive the adjusting blocks to move towards or away from the first axis, and each of the second driving assemblies is connected to the controller in communication.

4. The wafer surface polishing apparatus according to claim 3, wherein The visual recognition device is arranged on the side of the carrier plate facing the workbench, and the geometric center of the recognition part of the visual recognition device is in the projection of the turntable and the first axis in the projection of the turntable.

5. The wafer surface polishing apparatus according to any one of claims 1 to 4, wherein Further comprising: A clamping positioning device is connected to the turntable, and the clamping positioning device is configured to limit the wafer carried by the turntable.

6. The wafer surface polishing apparatus of claim 5, wherein The clamping positioning device comprises: A carrier is connected to the turntable, the center of the carrier coincides with the first axis, the carrier is provided with a plurality of adsorption holes in communication with an external vacuum pump, and the adsorption holes are configured to adsorb the wafer on the carrier; A plurality of clamping blocks are slidingly connected to the carrier, and the clamping blocks are arranged in a ring around the first axis, and each of the clamping blocks can move towards or away from the first axis.

7. The wafer surface polishing apparatus according to any one of claims 1 to 4, wherein There is no overlap or partial overlap between any adjacent preset areas.

8. A method of polishing a wafer surface, characterized by, The wafer surface polishing method applied to the wafer surface polishing device of any one of claims 1 to 7, wherein the surface to be polished of the wafer takes a point coinciding with the first axis of the turntable of the wafer surface polishing device as the origin, and the wafer surface polishing method comprises: identifying the surface to be polished by a visual recognition device, and dividing the surface to be polished into a plurality of nested preset areas with the origin as the center; sequentially scanning each of the preset areas from the origin to the edge of the wafer by the visual recognition device, and if at least one protrusion is identified in the scanned preset area, an identification image is generated, otherwise the next preset area is scanned; the controller receives the identification image and processes the identification image to obtain polishing data, and controls the adjusting assembly to drive at least one of the polishing devices to move in the vertical direction and / or the horizontal direction according to the polishing data, so that one of the protrusions in the preset area is polished to be flush with the surface to be polished by one of the polishing devices when the turntable is stationary, or at least one of the protrusions is simultaneously polished to be flush with the surface to be polished by a plurality of the polishing devices when the turntable rotates; wherein the controller comprises a controller and a processor connected in communication with each other, the controller receives the identification image and processes the identification image to obtain polishing data, and controls the adjusting assembly to drive at least one of the polishing devices to move in the vertical direction and / or the horizontal direction according to the polishing data, so that one of the protrusions in the preset area is polished to be flush with the surface to be polished by one of the polishing devices when the turntable is stationary, or at least one of the protrusions is simultaneously polished to be flush with the surface to be polished by a plurality of the polishing devices when the turntable rotates, comprising: the controller receives the identification image from the visual recognition device and sends the identification image to the processor; The processor receives the identification image, identifies the position of each protrusion in the preset area relative to the original point, the size of the protrusion, and the height of each protrusion protruding from the surface to be polished relative to the preset height according to the identification image, obtains the polishing data, and sends the polishing data to the controller. The controller controls the adjustment assembly to act according to the polishing data, so that the protrusions lower than or equal to the preset height are simultaneously polished to be flush with the surface to be polished by the plurality of polishing pieces, and each protrusion higher than the preset height is polished to be flush with the surface to be polished by one polishing piece.

Images