Wafer edge polishing system

Abstract

The invention discloses a wafer edge polishing system, and relates to the technical field of wafer processing. The wafer edge polishing system includes: a front end unit; the polishing unit is arranged close to the front end unit and at least comprises a wafer edge polishing device; the cleaning unit is used for cleaning and drying the surface of the wafer; the wafer edge polishing device comprises a loading and rotating mechanism used for loading and driving a wafer to rotate around a central axis; the polishing assembly is used for enabling a polishing belt to abut against the edge of the wafer so as to achieve wafer polishing; the polishing assembly comprises an upper polishing head, a lower polishing head and an edge polishing head, and polishing of the upper surface, the lower surface and / or the edge portion of the wafer is achieved through transverse and longitudinal feeding.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of semiconductor manufacturing technology, and in particular to a wafer edge polishing system. Background Art

[0002] In the existing wafer processing technology, after the wafer has undergone multiple processing steps such as etching, sharp burrs are likely to appear on the edge of the wafer, or the thickness of the wafer edge is uneven, resulting in uneven force in subsequent processing, causing the wafer to break and affecting product yield.

[0003] This requires the use of a wafer edge polishing system to polish the upper and lower surfaces and edges of the wafer, remove burrs on the edge of the wafer, and ensure that the thickness of the wafer edge is uniform.

[0004] Existing wafer edge polishing systems are usually single edge polishing, but a large number of tiny particles will be generated during the edge polishing process. If not cleaned in time, these contaminants will adhere to the edge of the wafer and increase the difficulty of subsequent cleaning.

[0005] At the same time, the existing wafer edge polishing mechanism is only equipped with one polishing head, and the single polishing head needs to be flipped multiple times to complete the entire polishing process. During the edge polishing process, the wafer needs to perform three processes: edge upper and lower surface polishing and edge polishing. The polishing head structure needs to be flipped multiple times to complete the three polishing processes, which will affect the processing efficiency of the wafer; and the flipping action of the polishing head structure requires a large space, which increases the space occupied by the wafer edge processing device and is not conducive to the reasonable arrangement of equipment in the Fab plant.

[0006] In addition, when polishing the upper and lower surfaces of the edge, the positive polishing pressure of a single polishing head on the wafer will cause the wafer to become unstable and deform, affecting the polishing effect of the wafer and possibly causing the wafer to break. Summary of the invention

[0007] In view of this, an embodiment of the present application provides a wafer edge polishing system to at least partially solve the above-mentioned problems.

[0008] According to an embodiment of the present application, a wafer edge polishing system is provided, which includes:

[0009] Front end unit;

[0010] a polishing unit, disposed adjacent to the front end unit, comprising at least one wafer edge polishing device;

[0011] A cleaning unit for cleaning and drying the wafer surface;

[0012] The wafer edge polishing device comprises:

[0013] A loading and rotating mechanism is used to load and drive the wafer to rotate around the central axis;

[0014] A polishing assembly that presses the polishing tape against the edge of the wafer to achieve wafer polishing;

[0015] The polishing assembly includes an upper polishing head, a lower polishing head and an edge polishing head, which realizes polishing of the upper surface, the lower surface and / or the edge of the wafer by horizontal and vertical feeding;

[0016] The polishing assembly also includes a timing transmission assembly and a horizontal transmission assembly. The timing transmission assembly is connected to the upper polishing head and the lower polishing head to control the longitudinal feed of the upper polishing head and the lower polishing head to polish the upper surface and / or lower surface of the wafer edge; the horizontal transmission assembly is connected to the edge polishing head to control the lateral feed of the edge polishing head to polish the edge of the wafer.

[0017] In some embodiments, the wafer edge polishing system further includes a polishing transfer robot disposed between the polishing unit and the cleaning unit, wherein the polishing transfer robot is provided with a slide rail disposed along the length direction of the wafer edge polishing system to transfer the wafer within the polishing unit.

[0018] In some embodiments, the cleaning unit includes a cleaning module, a drying module and a cleaning transfer robot, the cleaning module and the drying module are arranged in parallel, the drying module is arranged adjacent to the front end unit; the cleaning transfer robot is arranged adjacent to the cleaning module and the drying module.

[0019] In some embodiments, the wafer edge polishing system further includes a pre-positioning module, which is disposed between the front-end unit and the polishing transfer robot to pre-position the wafer to be processed.

[0020] In some embodiments, the wafer edge polishing system further includes a buffer module, which is disposed between the wafer edge polishing device and the cleaning unit to buffer the wafers that have completed polishing.

[0021] In some embodiments, the number of the cleaning modules and the drying modules is at least two groups, which are vertically stacked.

[0022] In some embodiments, the timing transmission assembly includes a control shaft, an upper support shaft for fixing the upper polishing head, and a lower support shaft for fixing the lower polishing head. The three are arranged horizontally, and the control shaft is arranged between the upper support shaft and the lower support shaft; a control wheel is arranged axially on the control shaft, which meshes with the gears of the upper support shaft and the lower support shaft to adjust the longitudinal position of the upper polishing head and the lower polishing head.

[0023] In some embodiments, the control shaft is configured with a first control wheel and a second control wheel, which are arranged at an interval; the first control wheel is engaged with the upper gear of the upper support shaft, and the second control wheel is engaged with the lower gear of the lower support shaft to drive the rotation of the cams of the upper support shaft and the lower support shaft, thereby changing the longitudinal position of the upper polishing head and the lower polishing head.

[0024] In some embodiments, the first control wheel and the second control wheel are incomplete gears to control their meshing with the upper gear and the lower gear, thereby adjusting the longitudinal positions of the upper polishing head and the lower polishing head.

[0025] In some embodiments, the first control wheel is a pair of sector gears, the sector gears are 1 / 4 of a circle, and the two are symmetrically arranged along the center of the circle; the second control wheel is a semicircular gear.

[0026] In some embodiments, the timing transmission component has at least the following three states: the first control wheel is engaged with the upper gear, and the second control wheel is not engaged with the lower gear; the first control wheel is engaged with the upper gear, and the second control wheel is engaged with the lower gear; the first control wheel is not engaged with the upper gear, and the second control wheel is engaged with the lower gear.

[0027] In some embodiments, the ends of the upper support shaft and the lower support shaft are provided with a fixing assembly, and the fixing assembly includes a fixing seat and a support plate, the support plate is connected to the fixing seat via a slider, and the support plate is provided with an upper polishing head and a lower polishing head.

[0028] In some embodiments, the fixed seat is configured with a vertical slide groove, and a horizontal connecting rod is configured on the side of the sliding block, the connecting rod is set through the slide groove, and a transmission roller is configured on the side of the connecting rod; the cams configured on the upper support shaft and the lower support shaft abut against the transmission roller, so that the connecting rod on the sliding block moves along the length direction of the slide groove to change the position of the support plate.

[0029] In some embodiments, an adapter frame is configured at the end of the connecting rod, and the adapter frame is a U-shaped frame. The transmission roller is rotatably connected to the adapter frame; the setting position of the transmission roller matches the setting position of the cam, so that the surface of the transmission roller abuts against the contour surface of the cam.

[0030] In some embodiments, the upper polishing head and the lower polishing head include a support block and a pad, the support block is arranged on the support plate, the pad is stacked on the support block, and the polishing belt passes around the guide rollers arranged on both sides of the pad and is wrapped around the outer side of the pad.

[0031] In some embodiments, the support block is a trapezoidal block, and the pad is disposed above a small cross-section of the trapezoidal block.

[0032] In some embodiments, the pad is made of a plastic non-metallic material, and its length matches the width of the polishing belt.

[0033] In some embodiments, the horizontal transmission assembly includes a vertical plate and a horizontal actuator, the horizontal actuator is arranged on the side of the vertical plate, and an edge polishing head is configured at its movable end; the edge polishing head has the same structure as the upper polishing head and the lower polishing head.

[0034] The beneficial effects of the present invention include:

[0035] a. The wafer edge polishing system provided is equipped with multiple wafer edge polishing devices to operate independently, thereby improving the flexibility of system operation;

[0036] b. The cleaning unit configured in the wafer edge polishing system includes a cleaning module and a drying module, and each functional module is stacked vertically to reduce the floor space;

[0037] c. The polishing and transmission robot is arranged between the wafer edge polishing device and the cleaning unit, and the polishing and transmission robot is arranged between the pre-positioning module and the buffer module to take into account the transmission between various functional modules;

[0038] d. The wafer edge polishing device is equipped with an upper polishing head, a lower polishing head and an edge polishing head which are independent of each other, and can realize the polishing of the wafer edge by horizontal and / or vertical feeding, thereby improving the flexibility of edge processing;

[0039] e. The upper polishing head, the lower polishing head and the edge polishing head of the polishing assembly do not need to process the wafer edge by swinging around a fixed point, which simplifies the structure of the polishing assembly and helps to ensure the stability of the operation of the polishing assembly;

[0040] f. The upper polishing head, the lower polishing head and the edge polishing head can be combined in pairs to process the edge of the wafer, and the wafer will not be warped or deformed toward one side, thereby preventing the negative impact of the warping deformation caused by the one-sided processing of the wafer edge on the polishing quality, and ensuring the polishing quality of the wafer edge;

[0041] g. The working area of ​​the edge polishing head overlaps with the working areas of the upper polishing head and the lower polishing head. That is, when the edge polishing head processes the edge of the wafer for the last time, it can cover the processing marks left by the upper polishing head and the lower polishing head, thereby avoiding the marks left by a single polishing head from affecting the polishing effect of the wafer edge;

[0042] h. The polishing assembly is configured with a timing transmission assembly, which is capable of controlling the longitudinal position of the upper polishing head and the lower polishing head to selectively process the upper and lower surfaces of the wafer;

[0043] i. The first control wheel and the second control wheel of the timing transmission assembly are mounted on the control shaft at a relatively fixed phase angle to change the operating state of the upper polishing head and the lower polishing head by driving the control wheel to rotate;

[0044] j. The first control wheel and the second control wheel are incomplete gears to control their meshing with the upper gear and the lower gear, thereby adjusting the longitudinal position of the upper polishing head and the lower polishing head;

[0045] k. Cams are arranged on the upper support shaft and the lower support shaft, and the cams are in contact with the transmission rollers connected to the upper polishing head and the lower polishing head, so as to ensure the position of the polishing head of the polishing assembly by driving and maintaining the state of the upper support shaft and / or the lower support shaft, so that the polishing belt is in contact with a specific working area at the edge of the wafer;

[0046] 1. The wafer edge polishing system provided in the present application is equipped with a cleaning unit. After the wafer edge is polished, the cleaning operation can be carried out without transferring to other equipment, thereby avoiding the long-term adhesion of particulate contaminants and helping to reduce the difficulty of removing contaminants. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0048] Figure 1 is a schematic diagram of a wafer edge polishing system provided by an embodiment of the present invention;

[0049] Figure 2 is a schematic diagram of a wafer edge polishing device provided by an embodiment of the present invention;

[0050] Figure 3 It is a schematic diagram of the working area corresponding to the edge of a wafer processed by a polishing head provided by an embodiment of the present invention;

[0051] Figure 4 is a schematic diagram of a polishing assembly provided by an embodiment of the present invention;

[0052] Figure 5 is a schematic diagram of a cam provided by an embodiment of the present invention being arranged on an upper support shaft;

[0053] Figure 6 It is a schematic diagram of the connection between the upper support shaft and the upper polishing head provided by one embodiment of the present invention;

[0054] Figure 7 is a schematic diagram of a fixing base provided by an embodiment of the present invention;

[0055] Figure 8 is a schematic diagram of a fixing assembly for removing a fixing seat provided by an embodiment of the present invention;

[0056] Fig. 9 is a schematic diagram of an upper polishing head provided by an embodiment of the present invention;

[0057] Fig.10 yes Figure 4 A schematic diagram of another perspective of the polishing assembly in FIG.

[0058] Fig.11 is a schematic diagram of a control wheel provided on a control shaft according to an embodiment of the present invention;

[0059] Fig.12 is a side view of a first control wheel and a second control wheel disposed on a control shaft;

[0060] Fig.13 is a schematic diagram of an overlapping area of ​​a wafer edge provided by an embodiment of the present invention;

[0061] Fig.14 is a schematic diagram of a scrubbing module provided in one embodiment of the present invention;

[0062] Fig.15 is a schematic diagram of a drying module provided in one embodiment of the present invention;

[0063] Fig.16 It is a schematic diagram of a cleaning unit provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0064] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the embodiments of the present application should fall within the scope of protection of the embodiments of the present application.

[0065] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0066] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0067] In the embodiments of the application, wafer (Wafer, W) is also called substrate (Substrate), and its meaning and actual function are equivalent.

[0068] Figure 1 1 is a wafer edge polishing system 1000 of the present invention, and its schematic diagram is as shown in FIG. Figure 1 As shown, the wafer edge polishing system 1000 includes:

[0069] The front-end unit 200 is used to store wafers to be polished and polished. A front-end robot 210 is configured inside the front-end unit 200 to transfer wafers in the wafer loading box of the front-end unit 200 to each functional module, and is responsible for transferring wafers that have been polished and cleaned to the wafer loading box of the front-end unit 200;

[0070] A polishing unit, disposed adjacent to the front-end unit 200, includes at least one wafer edge polishing device 100 to perform edge polishing of the wafer;

[0071] The cleaning unit 300 is used to clean and dry the wafer surface.

[0072] Furthermore, the wafer edge polishing system 1000 includes two wafer edge polishing devices 100, which are arranged horizontally along the length direction of the wafer edge polishing system 1000; the two wafer edge polishing devices 100 can be different functional modules, such as being responsible for rough polishing and fine polishing of the wafer edge respectively. Alternatively, the wafer edge polishing devices 100 can be the same functional modules, which can realize rough polishing and fine polishing of the wafer edge, and the two can operate independently.

[0073] Furthermore, the wafer edge polishing system 1000 also includes a transfer module, which includes a polishing transfer robot 410 and a cleaning transfer robot 420, wherein the polishing transfer robot 410 is arranged between the wafer edge polishing device 100 and the cleaning unit 300, and the cleaning transfer robot 420 is arranged between the functional modules of the cleaning unit 300 to be responsible for the transfer of the wafer inside the cleaning unit 300.

[0074] Specifically, the polishing transfer robot 410 is configured with a slide rail arranged along the horizontal direction to increase its horizontal span and expand the range of the robot's grasping; the cleaning transfer robot 420 is configured with a vertical slide rail, so that the cleaning transfer robot 420 can move vertically to adapt to the working conditions of vertical stacking of functional modules and improve the flexibility of wafer transmission.

[0075] Figure 1 In the illustrated embodiment, the wafer edge polishing system 1000 further includes a pre-positioning module 500, which is disposed between the front-end unit 200 and the polishing transfer robot 410 to pre-position the wafer to be processed, such as positioning the notch of the wafer, so as to accurately control the feeding of each polishing head of the polishing assembly 20 to achieve precise edge polishing.

[0076] Furthermore, the wafer edge polishing system 1000 also includes a buffer module 600, which is arranged between the wafer edge polishing device 100 and the cleaning unit 300 to buffer the polished wafers. The buffer module 600 generally includes a plurality of buffer layers, which are stacked vertically to buffer multiple wafers at the same time. At the same time, the buffer module 600 is configured with a moisturizing component, such as configuring an upper nozzle and a lower nozzle in the buffer layer to spray deionized water, ozone water, etc. toward the wafer to moisturize the wafer.

[0077] In the present invention, the pre-positioning module 500 and the cache module 600 are arranged close to the cleaning unit in the longitudinal direction, which is beneficial to prevent the polishing transfer robot 410 from interfering with the pre-positioning module 500 and the cache module 600 on both sides; in addition, the cleaning transfer robot 420 inside the cleaning unit away from the front end unit 200 is closer to the cache module 600, which is beneficial to reduce the configuration of the cleaning transfer robot 420 and control the cost of the wafer edge polishing system.

[0078] It should be noted that the wafer edge polishing system 1000 also includes a detection module 700, which is arranged at the end of the front-end unit 200 to detect the wafer before and after polishing, so as to obtain the effect of wafer edge polishing in real time and adjust the processing parameters of wafer edge polishing as needed.

[0079] The core module of the wafer edge polishing system, namely the wafer edge polishing device 100, is introduced in detail below. The wafer edge polishing device 100 includes:

[0080] The loading and rotating mechanism 10 is used to load and drive the wafer W to rotate around the central axis;

[0081] The polishing assembly 20 includes a polishing tape 20a ( Figure 6 ) is pressed against the edge of the wafer to achieve wafer polishing.

[0082] Furthermore, the loading and rotating mechanism 10 includes a tray 11, which is indicated by a dotted line, and a rotating motor is arranged below the tray 11, which drives the tray and the wafer W thereon to rotate around the central axis. Since the wafer W is concentrically arranged above the tray of the loading and rotating mechanism 10, it can also be said that the loading and rotating mechanism drives the wafer to rotate around the central axis of the loading and rotating mechanism. A groove / channel is arranged inside the tray, and the groove / channel is connected to a vacuum source through a pipeline to form a negative pressure between the tray and the wafer W, thereby adsorbing the wafer W to be polished on the upper surface of the tray.

[0083] Figure 2 In the embodiment, the polishing assembly 20 includes an upper polishing head 21, a lower polishing head 22 and an edge polishing head 23, which polish the upper surface S1, the lower surface S2 and / or the edge S3 of the wafer by horizontal and vertical feeding; wherein, Figure 3 The various working areas of wafer edge polishing are roughly shown. Edge polishing can remove the edges and corners of the wafer to eliminate the stress concentration caused by the edges and corners, making the wafer edge rounded.

[0084] In the present invention, the polishing assembly 20 further includes a timing transmission assembly 30, which is connected to the upper polishing head 21 and the lower polishing head 22 to control the longitudinal feeding of the upper polishing head 21 and the lower polishing head 22, thereby processing the upper surface and / or lower surface of the wafer edge.

[0085] Furthermore, the polishing assembly 20 further includes a horizontal transmission assembly 40 , which is connected to the edge polishing head 23 to control the lateral feeding of the edge polishing head 23 , thereby processing the edge portion of the wafer.

[0086] Figure 4 It is a schematic diagram of a polishing assembly 20 provided in one embodiment of the present invention, wherein the timing transmission assembly 30 includes a control shaft 31, an upper support shaft 32 and a lower support shaft 33, and the three are arranged parallel to the horizontal plane, wherein the upper support shaft 32 is used to fix the upper polishing head 21, and the lower support shaft 33 is used to fix the lower polishing head 22, and the control shaft 31 is horizontally arranged between the upper support shaft 32 and the lower support shaft 33.

[0087] Furthermore, the control shaft 31 is configured with a control wheel 34, and there are two control wheels 34, namely a first control wheel 34a and a second control wheel 34b, which are arranged at intervals along the axial direction of the control shaft 31, and the control wheel 34 is engaged with the gear 35 of the upper support shaft 32 and the lower support shaft 33 to adjust the longitudinal position of the upper polishing head 21 and the lower polishing head 22.

[0088] Specifically, an upper gear 35a is arranged on the upper support shaft 32, and its setting position is opposite to the first control wheel 34a on the control shaft 31, so that the first control wheel 34a and the upper gear 35a can be meshed. Correspondingly, a lower gear 35b is arranged on the lower support shaft 33, and its setting position is opposite to the second control wheel 34b on the control shaft 31, so that the second control wheel 34b and the lower gear 35b can be meshed.

[0089] It should be noted that the outer peripheral surface of the control wheel 34 is provided with teeth that mesh with the gear 35. Figure 4 The general shape of the control wheel 34 is only schematically shown; the control wheel 34 and the gear 35 are meshed with each other to drive the upper support shaft 32 and the lower support shaft 33 to rotate around their axes.

[0090] Figure 4 In the illustrated embodiment, a cam 36 is disposed on the upper support shaft 32 and the lower support shaft 33. The rotation of the upper support shaft 32 and the lower support shaft 33 can change the contour shape of the cam 36 and the abutment state of the follower, thereby adjusting the longitudinal position of the upper polishing head 21 and the lower polishing head 22.

[0091] In the present invention, the structure and connection relationship of the cam 36 of the upper support shaft 32 are the same as the structure and connection relationship of the cam 36 of the lower support shaft 33 .

[0092] Figure 5 The schematic diagram of the cam 36 disposed on the upper support shaft 32 is shown. The profile of the cam 36 is convex on one side and round on the opposite side, and the two are relatively smooth. The cam 36 rotates around the upper support shaft 32, and the shape of its outer profile determines the movement law of the follower. The follower here is the transmission roller 55 mentioned below, which can drive the upper polishing head 21 to move vertically to change its longitudinal position.

[0093] In the present invention, the ends of the upper support shaft 32 and the lower support shaft 33 are provided with fixing components 50 to fix the upper polishing head 21 and the lower polishing head 22 respectively. Figure 6 The fixing assembly 50 disposed on the upper support shaft 32 is taken as an example to illustrate the structural composition and connection relationship of the fixing assembly 50.

[0094] The fixing assembly 50 includes a fixing seat 51 and a supporting plate 52. Figure 6 As shown, the fixing seat 51 is arranged at the end of the upper supporting shaft 32 , the supporting plate 52 is an L-shaped structure, which is connected to the side of the fixing seat 51 through a slider 53 , and the upper polishing head 21 is arranged on the supporting plate 52 .

[0095] Furthermore, the fixing seat 51 is provided with a slide groove 51a, such as Figure 7As shown, the slide groove 51a is a through groove, which is arranged in the vertical direction.

[0096] The slider 53 is provided with Figure 8 The connecting rod 54 shown is arranged horizontally and passes through the slide groove 51a of the fixed seat 51. The end of the connecting rod 54 is provided with a transmission roller 55. The cam 36 abuts against the transmission roller 55 to change the vertical position of the slider 53 fixed by the connecting rod 54 as the profile of the cam 36 changes, so that the connecting rod 54 on the slider 53 moves along the length direction of the slide groove 51a to change the position of the support plate 52, that is, change the longitudinal position of the support plate 52 and the upper polishing head 21 thereon.

[0097] Figure 8 In the illustrated embodiment, an adapter frame 56 is disposed at the end of the connecting rod 54. The adapter frame 56 is a U-shaped frame, and the driving roller 55 is rotatably connected to the adapter frame 56 via a rotating shaft.

[0098] Furthermore, the setting position of the transmission roller 55 matches the setting position of the cam 36, so that the surface of the transmission roller 55 abuts against the contour surface of the cam 36, so that the slider 53 is driven up and down by the rotating cam 36 to change the vertical position of the support plate 52 and the upper polishing head 21 thereon.

[0099] The upper polishing head 21 includes a support block 21a and a pad 21b. Fig. 9 As shown, the support block 21a is disposed on the side of the support plate 52; that is, the pad 21b is stacked on the side of the support block 21a.

[0100] Furthermore, the support block 21a is a trapezoidal block, and the pad 21b is arranged above the small cross section of the trapezoidal block, such as Figure 6 As shown, the polishing tape 20a is wrapped around the outside of the pad 21b without interfering with the edge of the support block 21a, thereby maintaining the polishing tape in a good use state.

[0101] In the present invention, the pad 21b is made of a plastic non-metallic material so that the polishing belt on the outer side of the pad 21b can adapt to the contour of the wafer edge and completely fit the surface to be polished of the wafer to obtain a polishing quality that meets the process requirements.

[0102] Furthermore, the length of the pad 21 b matches the width of the polishing belt, so that the moving polishing belt is in continuous contact with the surface to be processed of the wafer, thereby ensuring the efficiency of wafer edge polishing.

[0103] The polishing belt passes through the guide rollers 57 disposed on both sides of the pad 21b and covers the outer side of the pad 21b. Specifically, the guide rollers 57 are mounted on the fixing seat 51 and symmetrically disposed on both sides of the pad 21b; the polishing belt 20a passes through one guide roller 57, the pad 21b and another guide roller 57 in sequence and covers the outer side of the pad 21b.

[0104] Figure 4 In the embodiment shown, the horizontal transmission assembly 40 includes a vertical plate 41 and a horizontal actuator 42, wherein the horizontal actuator 42 is arranged on the side of the vertical plate 41, and the movable end thereof is provided with an edge polishing head 23, and a guide roller 57 for limiting the polishing belt is arranged on the vertical plate 41, as shown in FIG. Figure 4 As shown, the edge polishing head 23 is substantially the same as the upper polishing head 21 and the lower polishing head 22, and will not be described in detail herein.

[0105] It should be noted that the horizontal actuator 42 can be a linear moving module such as a cylinder or an electric cylinder, and the edge polishing head 23 is arranged at the moving end of the horizontal actuator 42 so that the polishing belt covered by the edge polishing head 23 can be brought into contact with the edge of the wafer to polish the edge of the wafer.

[0106] Fig.10 In the illustrated embodiment, the first control wheel 34 a and the second control wheel 34 b are incomplete gears to control their meshing with the upper gear 35 a and the lower gear 35 b , thereby adjusting the longitudinal positions of the upper polishing head 21 and the lower polishing head 22 .

[0107] Furthermore, the first control wheel 34a is a pair of sector gears, which are 1 / 4 of the circumference and are symmetrically arranged along the center of the circle, that is, the corresponding center angle of the sector gears is 90°; the second control wheel 34b is a semicircular gear, and its corresponding center angle is 180°.

[0108] Fig.11 Schematic diagram of a control wheel 34 provided by an embodiment of the present invention being arranged on a control shaft 31, wherein a first control wheel 34a and a second control wheel 34b are arranged at intervals along the axial direction of the control shaft 31, and the first control wheel 34a and the second control wheel 34b are installed on the control shaft 31 at a relatively fixed phase angle, so that the timing transmission component 30 can have at least the following three states:

[0109] State 1: the first control wheel 34a is meshed with the upper gear 35a, and the second control wheel 34b is not meshed with the lower gear 35b;

[0110] State 2: the first control wheel 34a is meshed with the upper gear 35a, and the second control wheel 34b is meshed with the lower gear 35b;

[0111] State three: the first control wheel 34a is not meshed with the upper gear 35a, and the second control wheel 34b is meshed with the lower gear 35b.

[0112] When the timing transmission assembly 30 is in state 1, the first control wheel 34a is only meshed with the upper gear 35a, and the upper support shaft 32 rotates around the axis to abut against the transmission roller 55 through the cam 36, so that the upper polishing head 21 changes its position as the support plate 52 moves vertically, and the polishing belt wrapped around the outer side of the pad 21b of the upper polishing head 21 abuts against the upper surface S1 of the wafer ( Figure 3 ), to polish the upper surface of the edge of the wafer.

[0113] When the timing transmission assembly 30 is in state two, the first control wheel 34a is meshed with the upper gear 35a, and the second control wheel 34b is meshed with the lower gear 35b, so as to simultaneously control the upper polishing head 21 and the lower polishing head 22 to move toward the wafer, so that the corresponding polishing belts abut against the upper and lower surfaces of the edge of the wafer to polish the upper and lower surfaces of the edge of the wafer.

[0114] Since the upper polishing head 21 and the lower polishing head 22 are in contact with the upper and lower surfaces of the wafer at the same time, the wafer does not warp or deform toward one side, thereby preventing the negative impact of warping or deformation caused by one-sided processing of the wafer edge on the polishing quality, thereby ensuring the polishing quality of the wafer edge.

[0115] When the timing transmission assembly 30 is in state three, the second control wheel 34b meshes with the lower gear 35b, and the lower support shaft 33 rotates around the axis to abut against the transmission roller 55 through the cam 36, so that the lower polishing head 22 changes its position as the support plate 52 moves vertically, and the polishing belt wrapped around the outer side of the pad 21b of the lower polishing head 22 abuts against the lower surface S2 of the wafer ( Figure 3 ), to polish the lower surface of the edge of the wafer.

[0116] In the present invention, when the control wheel 34 is fixed to the control shaft 31, a sector gear of the first control wheel 34a overlaps with the second control wheel 34b in the circumferential direction, as shown in FIG. Fig.12 As shown, in accordance with the state 2 of the timing transmission assembly 30, the two control wheels 34 are respectively engaged with the upper gear 35a and the lower gear 35b to control the upper polishing head 21 and the lower polishing head 22 to polish the edge of the wafer simultaneously.

[0117] It should be noted that the timing transmission assembly 30 also has state four: the first control wheel 34a is not engaged with the upper gear 35a, and the second control wheel 34b is not engaged with the lower gear 35b; in this state, the control wheel 34 is not engaged with the upper gear 35a and the lower gear 35b, that is, the upper polishing head 21 and the lower polishing head 22 do not polish the edge of the wafer at the same time.

[0118] In order to realize the fourth state, when the control wheel 34 is fixed to the control shaft 31, the first control wheel 34a and the second control wheel 34b do not overlap at all in the 1 / 4 area of ​​the circumference. Fig.12 As shown, the control wheel 34 is not engaged with the upper gear 35a and the lower gear 35b.

[0119] It is understandable that when the timing transmission assembly 30 is in state 4, the upper polishing head 21 and the lower polishing head 22 of the polishing assembly 20 do not process the edge of the wafer. At this time, the horizontal transmission assembly 40 can be controlled to use the edge polishing head 23 to process the edge of the wafer.

[0120] Combine the following Figure 2 The general operation process of the wafer edge polishing device 100 is briefly described as follows:

[0121] Step 1: placing the wafer to be processed on the tray 11 of the loading rotating mechanism 10;

[0122] Specifically, an external robot transfers the wafer to be processed to the tray 11 of the loading and rotating mechanism 10, and the wafer is concentrically arranged on the tray 11 to provide a reference for the control of the polishing assembly 20; the tray 11 sucks the wafer by vacuum adsorption, and the tray 11 and the wafer thereon are driven to rotate by the loading and rotating mechanism 10;

[0123] Step 2: The polishing head of the polishing assembly 20 is fed horizontally and / or vertically so that the polishing tape abuts against the upper surface, the lower surface and / or the edge of the wafer;

[0124] Specifically, the polishing assembly 20 controls the lateral and / or longitudinal feeding of the polishing head through the timing transmission assembly 30 and the horizontal transmission assembly 40, so that the polishing belt abuts against the area to be processed;

[0125] Step three: the polishing belt moves to polish the upper surface, lower surface and / or edge of the wafer.

[0126] After the polishing head is moved into position, the polishing belt moves to process the upper surface, the lower surface and / or the edge portion of the wafer by the polishing belt.

[0127] In step 2, two of the polishing heads of the polishing assembly 20 operate simultaneously to achieve polishing of the wafer edge. Specifically, the upper polishing head 21 and the lower polishing head 22 process the edge of the wafer simultaneously, the upper polishing head 21 and the edge polishing head 23 process the edge of the wafer simultaneously, or the lower polishing head 22 and the edge polishing head 23 process the edge of the wafer simultaneously. In the above processing method, the upper surface, the lower surface and at least two parts of the edge of the wafer edge are subjected to the load applied by the polishing head, which can avoid the wafer edge from being warped by the eccentric load to a certain extent, thereby ensuring the processing quality of the wafer edge.

[0128] When the upper polishing head 21 and the lower polishing head 22 process the edge of the wafer at the same time, the timing transmission assembly 30 drives the control shaft 31 to rotate, so that the first control wheel 34a engages with the upper gear 35a, and the second control wheel 34b engages with the lower gear 35b, and then the polishing belts of the upper polishing head 21 and the lower polishing head 22 respectively abut against the upper and lower surfaces of the wafer to achieve polishing of the upper and lower surfaces of the wafer.

[0129] After the upper and lower surfaces of the wafer are polished, the horizontal transmission assembly 40 controls the edge polishing head 23 to move horizontally, and the polishing belt on the edge of the wafer ( Figure 3 S3) is shown to complete polishing of the edge portion of the wafer.

[0130] In some embodiments, the working area of ​​the edge polishing head 23 overlaps with the working areas of the upper polishing head 21 and the lower polishing head 22 (eg, Fig.13 That is, when the edge polishing head 23 processes the edge of the wafer for the last time, it can cover the processing marks left by the upper polishing head 21 and the lower polishing head 22, thereby avoiding the marks left by a single polishing head from affecting the polishing effect of the wafer edge.

[0131] In the present invention, the length of the overlapping area So is less than or equal to 1 / 4 of the upper surface S1 or the lower surface S2, so that the traces left by the single polishing head can be eliminated through the edge polishing head 23 to ensure the effect of wafer edge polishing.

[0132] It is understandable that the upper polishing head 21 or the lower polishing head 22 can also process the edge of the wafer separately. When the upper polishing head 21 or the lower polishing head 22 processes the edge of the wafer separately, the pad 21b of the polishing head on the other side abuts against the surface of the wafer, and the pad 21b is not covered with the polishing tape. In this way, the pad 21b of the polishing head on the other side can provide support for the wafer to prevent the wafer from warping and deformation and affecting the edge polishing quality.

[0133] It can be understood that each polishing head of the polishing assembly 20 can process the upper surface, lower surface and edge of the edge of the wafer at the same time. Since the polishing belts of adjacent polishing heads influence each other, it is finally necessary to use the edge polishing head 23 to perform overall processing on the edge of the wafer to avoid traces left by a single polishing head and ensure the quality of wafer edge polishing.

[0134] In the present invention, the cleaning unit 300 includes a cleaning module 310 and a drying module 320, which are arranged in parallel. Figure 1 As shown, the drying module 320 is arranged close to the front-end unit 200. This is because the cleanliness of the wafer after drying is high, and the transmission path of the wafer needs to be shortened to maintain the cleanliness of the wafer surface.

[0135] In the present invention, the cleaning module 310 is a scrubbing module, and its schematic diagram is as shown in FIG. Fig.14 As shown, the wafer is clamped horizontally and driven to rotate by a driving mechanism, and cleaning brushes are arranged on the upper and lower surfaces of the wafer to remove residual contaminants on the surface of the wafer.

[0136] The drying module 320 is a horizontal drying module, and its schematic diagram is as shown in FIG. Fig.15 As shown, the drying module 320 peels off the water film on the surface of the wafer based on the Marangoni effect, thereby obtaining a wafer with a clean surface.

[0137] In some embodiments, the number of the cleaning modules 310 and the drying modules 320 is two groups, which are stacked vertically, such as Fig.16 As shown, the footprint of the equipment can be reduced, and multiple cleaning and drying modules can be arranged in a relatively small space, thereby improving the cleaning capacity of the wafer edge polishing system.

[0138] Figure 1 In the illustrated embodiment, a dotted line with an arrow is used to indicate a transport path of a wafer in the wafer edge polishing system 1000. The transport process of the wafer in this embodiment is briefly described below:

[0139] First, the front-end robot of the front-end unit 200 transfers the wafer to the pre-positioning module 500 to pre-position the wafer;

[0140] Next, the polishing transfer robot 410 transfers the wafer to a wafer edge polishing apparatus 100 to polish the wafer edge using the polishing assembly 20; Next, the polishing transfer robot 410 transfers the wafer from one wafer edge polishing apparatus 100 to another wafer edge polishing apparatus 100 to continue polishing the wafer edge;

[0141] When the wafer has completed edge polishing, the polishing transfer robot 410 transfers the wafer to the buffer module 600;

[0142] Next, the cleaning transfer robot 420 or the polishing transfer robot 410 near the buffer module 600 transfers the wafer to the cleaning unit 300 to perform a cleaning process on the wafer;

[0143] Next, the cleaning and transferring robot 420 disposed between the cleaning module 310 and the drying module 320 transfers the wafer to the drying module 320 to dry the wafer;

[0144] Finally, when the wafers are completely dried, the front-end robot 210 transfers the dried wafers to a wafer loading box of the front-end unit 200 .

[0145] Those of ordinary skill in the art will appreciate that the units and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the embodiments of the present application.

[0146] The above implementation methods are only used to illustrate the embodiments of the present application, and are not limitations on the embodiments of the present application. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the embodiments of the present application. Therefore, all equivalent technical solutions also belong to the scope of the embodiments of the present application. The scope of patent protection of the embodiments of the present application should be limited by the claims.

Claims

1. A wafer edge polishing system, characterized in that: include: Front end unit; a polishing unit, disposed adjacent to the front end unit, comprising at least one wafer edge polishing device; A cleaning unit for cleaning and drying the wafer surface; The wafer edge polishing device comprises: A loading and rotating mechanism is used to load and drive the wafer to rotate around the central axis; A polishing assembly that presses the polishing tape against the edge of the wafer to achieve wafer polishing; The polishing assembly includes an upper polishing head, a lower polishing head and an edge polishing head, which realizes polishing of the upper surface, the lower surface and / or the edge of the wafer by horizontal and vertical feeding; The polishing assembly also includes a timing transmission assembly and a horizontal transmission assembly. The timing transmission assembly is connected to the upper polishing head and the lower polishing head to control the longitudinal feed of the upper polishing head and the lower polishing head to polish the upper surface and / or lower surface of the wafer edge; the horizontal transmission assembly is connected to the edge polishing head to control the lateral feed of the edge polishing head to polish the edge of the wafer.

2. The wafer edge polishing system according to claim 1, characterized in that: It also includes a polishing transfer robot, which is arranged between the polishing unit and the cleaning unit. The polishing transfer robot is equipped with a slide rail arranged along the length direction of the wafer edge polishing system to transfer the wafer inside the polishing unit.

3. The wafer edge polishing system according to claim 1, characterized in that: The cleaning unit comprises a cleaning module, a drying module and a cleaning and transporting robot. The cleaning module and the drying module are arranged in parallel. The drying module is arranged adjacent to the front-end unit. The cleaning and transporting robot is arranged adjacent to the cleaning module and the drying module.

4. The wafer edge polishing system according to claim 2, characterized in that: It also includes a pre-positioning module, which is arranged between the front-end unit and the polishing and transmission robot to pre-position the wafer to be processed.

5. The wafer edge polishing system according to claim 1, characterized in that: The device also includes a buffer module, which is arranged between the wafer edge polishing device and the cleaning unit to buffer the wafers that have been polished.

6. The wafer edge polishing system according to claim 3, characterized in that: The number of the cleaning modules and the drying modules is at least two groups, which are vertically stacked.

7. The wafer edge polishing system according to claim 1, characterized in that: The timing transmission assembly includes a control shaft, an upper support shaft for fixing the upper polishing head, and a lower support shaft for fixing the lower polishing head. The three are arranged horizontally, and the control shaft is arranged between the upper support shaft and the lower support shaft; a control wheel is arranged axially on the control shaft, which meshes with the gears of the upper support shaft and the lower support shaft to adjust the longitudinal position of the upper polishing head and the lower polishing head.

8. The wafer edge polishing system according to claim 7, characterized in that: The control shaft is configured with a first control wheel and a second control wheel, which are arranged at an interval; the first control wheel is engaged with the upper gear of the upper support shaft, and the second control wheel is engaged with the lower gear of the lower support shaft to drive the rotation of the cams of the upper support shaft and the lower support shaft, thereby changing the longitudinal position of the upper polishing head and the lower polishing head.

9. The wafer edge polishing system according to claim 8, characterized in that: The first control wheel and the second control wheel are incomplete gears to control their meshing with the upper gear and the lower gear, thereby adjusting the longitudinal positions of the upper polishing head and the lower polishing head.

10. The wafer edge polishing system according to claim 9, characterized in that: The first control wheel is a pair of sector gears, the sector gears are 1 / 4 of the circumference, and the two are symmetrically arranged along the center of the circle; the second control wheel is a semicircular gear.

11. The wafer edge polishing system according to claim 10, characterized in that: The timing transmission component has at least the following three states: the first control wheel is meshed with the upper gear, and the second control wheel is not meshed with the lower gear; the first control wheel is meshed with the upper gear, and the second control wheel is meshed with the lower gear; the first control wheel is not meshed with the upper gear, and the second control wheel is meshed with the lower gear.

12. The wafer edge polishing system according to claim 8, characterized in that: The ends of the upper support shaft and the lower support shaft are provided with fixing components, and the fixing components include a fixing seat and a supporting plate. The supporting plate is connected to the fixing seat via a sliding block, and an upper polishing head and a lower polishing head are provided on the supporting plate.

13. The wafer edge polishing system according to claim 12, characterized in that: The fixed seat is configured with a vertical slide groove, and a horizontal connecting rod is configured on the side of the sliding block. The connecting rod is set through the slide groove, and a transmission roller is configured on the side of the connecting rod; the cams configured on the upper support shaft and the lower support shaft abut against the transmission roller, so that the connecting rod on the sliding block moves along the length direction of the slide groove to change the position of the support plate.

14. The wafer edge polishing system according to claim 13, characterized in that: The end of the connecting rod is provided with an adapter frame, the adapter frame is a U-shaped frame, and the transmission roller is rotatably connected to the adapter frame; the setting position of the transmission roller matches the setting position of the cam, so that the surface of the transmission roller abuts against the contour surface of the cam.

15. The wafer edge polishing system according to claim 12, wherein: The upper polishing head and the lower polishing head include a support block and a pad, wherein the support block is arranged on the support plate, the pad is stacked on the support block, and the polishing belt passes around guide rollers arranged on both sides of the pad and covers the outer side of the pad.

16. The wafer edge polishing system according to claim 15, characterized in that: The support block is a trapezoidal block, and the pad is arranged above the small cross section of the trapezoidal block.

17. The wafer edge polishing system according to claim 15, characterized in that: The pad is made of a plastic non-metal material, and its length matches the width of the polishing belt.

18. The wafer edge polishing system according to claim 1, wherein: The horizontal transmission assembly includes a vertical plate and a horizontal actuator. The horizontal actuator is arranged on the side of the vertical plate, and an edge polishing head is arranged at the movable end thereof. The edge polishing head has the same structure as the upper polishing head and the lower polishing head.

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