Wafer edge polishing device and polishing method

Abstract

The invention discloses a wafer edge polishing device and a polishing method, and relates to the technical field of wafer processing. 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 is used for polishing the upper surface, the lower surface and / or the edge part of the wafer through transverse and longitudinal feeding; the polishing assembly further comprises a time sequence transmission assembly and a horizontal transmission assembly, and the time sequence transmission assembly is connected with the upper polishing head and the lower polishing head so as to control longitudinal feeding of the upper polishing head and the lower polishing head to polish the upper surface and / or the lower surface of the edge of the wafer. The horizontal transmission assembly is connected with the edge polishing head so as to control transverse feeding of the edge polishing head to polish the edge portion of the wafer.

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 device and a polishing method. Background Art

[0002] In the existing wafer processing technology, after the wafer undergoes multiple processing technologies such as etching, sharp burrs are likely to exist on the wafer edge, or the thickness of the wafer edge is uneven, which will cause uneven stress in subsequent processing, resulting in wafer breakage and affecting the product yield.

[0003] The wafer edge polishing process is divided into upper and lower surface polishing of the edge and edge polishing. 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 edge polishing process.

[0004] During the wafer edge polishing process, three process steps of upper and lower surface polishing of the edge and edge polishing need to be performed. 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; moreover, the flipping action of the polishing head structure requires a large amount of space, which increases the space occupation of the wafer edge processing device and is not conducive to the reasonable arrangement of equipment in the Fab factory.

[0005] In addition, during the upper and lower surface polishing of the edge, the polishing normal pressure of a single polishing head on the wafer will cause the wafer to be unstable and deformed, affecting the polishing effect of the wafer and possibly causing the wafer to break. Summary of the Invention

[0006] In view of this, the embodiments of the present application provide a wafer edge polishing device and a polishing method to at least partially solve the above problems.

[0007] According to the first aspect of the embodiments of the present application, a wafer edge polishing device is provided, which includes:

[0008] A loading and rotating mechanism for loading and driving the wafer to rotate around the central axis;

[0009] A polishing assembly that presses a polishing belt against the edge of the wafer to achieve wafer polishing;

[0010] The polishing assembly includes an upper polishing head, a lower polishing head, and an edge polishing head, which achieve polishing of the upper surface, lower surface, and / or edge portion of the wafer through lateral and longitudinal feeding;

[0011] The polishing assembly further 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 feeding 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 feeding of the edge polishing head to polish the edge portion of the wafer.

[0012] In some embodiments, the timing drive 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 disposed between the upper support shaft and the lower support shaft; a control wheel is axially disposed on the control shaft and meshes with the gears of the upper support shaft and the lower support shaft to adjust the longitudinal positions of the upper polishing head and the lower polishing head.

[0013] In some embodiments, the control shaft is configured with a first control wheel and a second control wheel, which are spaced apart; the first control wheel meshes with the upper gear of the upper support shaft, and the second control wheel meshes 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 positions of the upper polishing head and the lower polishing head.

[0014] 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.

[0015] In some embodiments, 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 semi-circular gear.

[0016] In some embodiments, the timing drive assembly has at least the following three states: the first control wheel meshes with the upper gear and the second control wheel does not mesh with the lower gear; the first control wheel meshes with the upper gear and the second control wheel meshes with the lower gear; the first control wheel does not mesh with the upper gear and the second control wheel meshes with the lower gear.

[0017] In some embodiments, one sector gear of the first control wheel overlaps with the second control wheel in the circumferential direction.

[0018] In some embodiments, the first control wheel and the second control wheel do not overlap completely in a 1 / 4 area of the circumference.

[0019] In some embodiments, the ends of the upper support shaft and the lower support shaft are configured with a fixing assembly, the fixing assembly includes a fixing seat and a support plate, the support plate is connected to the fixing seat through a slider, and the upper polishing head and the lower polishing head are configured on the support plate.

[0020] In some embodiments, the fixing seat is configured with a vertical chute, the side of the slider is configured with a horizontal connecting rod, the connecting rod is disposed through the chute, and a transmission roller is disposed 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 slider moves along the length direction of the chute to change the position of the support plate.

[0021] In some embodiments, a transfer bracket is disposed at the end of the connecting rod. The transfer bracket is a U-shaped bracket, and the driving roller is rotatably connected to the transfer bracket; the position where the driving roller is disposed matches the position where the cam is disposed, such that the surface of the driving roller abuts against the profile surface of the cam.

[0022] In some embodiments, the upper polishing head and the lower polishing head include a support block and a backing plate. The support block is disposed on the support plate, the backing plate is stacked on the support block, and the polishing belt bypasses the guide rollers disposed on both sides of the backing plate and covers the outside of the backing plate.

[0023] In some embodiments, the support block is a trapezoidal block, and the backing plate is disposed above the small cross-section of the trapezoidal block.

[0024] In some embodiments, the backing plate is made of a plastic non-metallic material, and its length matches the width of the polishing belt.

[0025] In some embodiments, the horizontal transmission assembly includes a vertical plate and a horizontal actuator. The horizontal actuator is disposed on the side of the vertical plate, and its moving end is configured with an edge polishing head; the edge polishing head has the same structure as the upper polishing head and the lower polishing head.

[0026] According to a second aspect of the embodiments of the present application, a wafer edge polishing method is provided. The method uses the wafer edge polishing device described above and includes:

[0027] Step 1, placing the wafer to be processed on the tray of the loading and rotating mechanism;

[0028] Step 2, the polishing heads of the polishing assembly are fed horizontally and / or longitudinally, such that the polishing belt abuts against the upper surface, the lower surface, and / or the edge portion of the wafer;

[0029] Step 3, the polishing belt moves to polish the upper surface, the lower surface, and / or the edge portion of the wafer.

[0030] In some embodiments, two of the polishing heads of the polishing assembly operate simultaneously to polish the edge of the wafer.

[0031] In some embodiments, when the upper polishing head or the lower polishing head processes the wafer edge alone, the backing plate of the polishing head on the other side abuts against the wafer surface, and the backing plate does not cover the polishing belt.

[0032] In some embodiments, the timing transmission assembly drives the control shaft to rotate, such that the first control wheel meshes with the upper gear, and the second control wheel meshes with the lower gear. Further, the polishing belts of the upper polishing head and the lower polishing head respectively abut against the upper and lower surfaces of the wafer to polish the upper and lower surfaces of the wafer.

[0033] In some embodiments, after the upper and lower surfaces of the wafer are polished, the horizontal transmission assembly controls the horizontal movement of the edge polishing head, and the polishing belt thereon abuts against the edge portion of the wafer to complete the polishing of the edge portion of the wafer.

[0034] In some embodiments, there is an overlapping portion between the working area of the edge polishing head and the working areas of the upper polishing head and the lower polishing head.

[0035] The beneficial effects of the present invention include:

[0036] a. The provided wafer edge polishing device is configured with an upper polishing head, a lower polishing head, and an edge polishing head that are independent of each other. It can achieve the polishing of the wafer edge through lateral and / or longitudinal feeding, improving the flexibility of edge processing;

[0037] b. The upper polishing head, the lower polishing head, and the edge polishing head of the polishing assembly do not need to swing around a fixed point to process the wafer edge, simplifying the structure of the polishing assembly and facilitating the guarantee of the stability of the operation of the polishing assembly;

[0038] c. 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. The wafer does not warp and deform towards one side, thereby preventing the negative impact of the warping and deformation caused by unilateral processing of the wafer edge on the polishing quality and ensuring the polishing quality of the wafer edge;

[0039] d. There is an overlapping area between the working area of the edge polishing head and the working areas of the upper polishing head and the lower polishing head. That is, when the edge polishing head finally processes the edge portion of the wafer, 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;

[0040] e. The polishing assembly is configured with a timing transmission assembly, which can control the longitudinal positions of the upper polishing head and the lower polishing head to selectively process the upper and lower surfaces of the wafer;

[0041] f. The first control wheel and the second control wheel of the timing transmission assembly are installed on the control shaft with a relatively fixed phase angle to change the operating states of the upper polishing head and the lower polishing head by driving the control wheels to rotate;

[0042] g. 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;

[0043] h. Cams are arranged on the upper support shaft and the lower support shaft. The cams abut against the transmission rollers connected to the upper polishing head and the lower polishing head to ensure the positions of the polishing heads of the polishing assembly by driving and maintaining the states of the upper support shaft and / or the lower support shaft, so that the polishing belt abuts against a specific working area of the wafer edge;

[0044] i. The backing plate of the polishing head is made of a plastic non-metallic material, which can be adaptively deformed so that the polishing belt wrapped around the outer side of the backing plate is in close contact with the surface to be polished, ensuring the edge polishing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0046] Figure 1 is a schematic diagram of a wafer edge polishing device provided by an embodiment of the present invention;

[0047] Figure 2 is a schematic diagram of the working area corresponding to the wafer edge processed by the polishing head provided by an embodiment of the present invention;

[0048] Figure 3 is a schematic diagram of a polishing assembly provided by an embodiment of the present invention;

[0049] Figure 4 is a schematic diagram of a cam disposed on an upper support shaft provided by an embodiment of the present invention;

[0050] Figure 5 is a schematic diagram of the connection between the upper support shaft and the upper polishing head provided by an embodiment of the present invention;

[0051] Figure 6 is a schematic diagram of a fixed seat provided by an embodiment of the present invention;

[0052] Figure 7 is a schematic diagram of a fixing component for removing the fixed seat provided by an embodiment of the present invention;

[0053] Figure 8 is a schematic diagram of the upper polishing head provided by an embodiment of the present invention;

[0054] Figure 9 is Figure 3 a schematic diagram of another perspective of the polishing assembly in

[0055] Figure 10 is a schematic diagram of a control wheel disposed on a control shaft provided by an embodiment of the present invention;

[0056] Figure 11 is a side view of the first control wheel and the second control wheel disposed on the control shaft;

[0057] Figure 12 is a flowchart of a wafer edge polishing method provided by an embodiment of the present invention;

[0058] Figure 13 It is a schematic diagram of the overlapping area at the edge of a wafer provided by an embodiment of the present invention. Detailed implementation manners

[0059] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art shall fall within the protection scope of the embodiments of the present application.

[0060] The terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms of "a", "the", and "said" used in the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0061] It should be understood that although the terms "first", "second", "third", etc. may be used in the present application to describe various information, such 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 the present 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 with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0062] In the embodiments of the application, a wafer (Wafer, W) is also referred to as a substrate (Substrate), and their meanings and actual functions are equivalent.

[0063] Figure 1 It is a schematic diagram of a wafer edge polishing device 100 provided by an embodiment of the present invention. The wafer edge polishing device 100 includes:

[0064] A loading and rotating mechanism 10 for loading and driving the wafer W to rotate around the central axis;

[0065] A polishing assembly 20 that presses a polishing belt 20a ( Figure 5 shown) against the edge of the wafer to achieve wafer polishing.

[0066] Further, the loading and rotating mechanism 10 includes a tray 11, which is shown by a dashed line. A rotating motor is provided below the tray 11, and the rotating motor 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 provided 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.

[0067] Figure 1 In [the figure], the polishing assembly 20 includes an upper polishing head 21, a lower polishing head 22, and an edge polishing head 23, which achieve polishing of the upper surface S1, the lower surface S2, and / or the edge portion S3 of the wafer through lateral and longitudinal feeding; among them, Figure 2 Generally shows each operation area of wafer edge polishing. Edge polishing can remove the sharp corners of the wafer edge to eliminate the stress concentration caused by the sharp corners and make the wafer edge round.

[0068] 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 machining the upper surface and / or the lower surface of the wafer edge.

[0069] Further, 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 machining the edge portion of the wafer.

[0070] Figure 3 Is a schematic diagram of the polishing assembly 20 provided by an embodiment of the present invention. Among them, the timing transmission assembly 30 includes a control shaft 31, an upper support shaft 32, and a lower support shaft 33, all of which are arranged parallel to the horizontal plane. Among them, the upper support shaft 32 is used to fix the upper polishing head 21, 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.

[0071] Further, the control shaft 31 is configured with control wheels 34, and the number of control wheels 34 is two, namely a first control wheel 34a and a second control wheel 34b. The two are spaced apart along the axial direction of the control shaft 31, and the control wheels 34 are engaged with the gears 35 of the upper support shaft 32 and the lower support shaft 33 to adjust the longitudinal positions of the upper polishing head 21 and the lower polishing head 22.

[0072] 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 as to facilitate the meshing of the first control wheel 34a and the upper gear 35a; 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 as to facilitate the meshing of the second control wheel 34b and the lower gear 35b.

[0073] 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 3 only schematically shows the general shape of the control wheel 34; the control wheel 34 meshes with the gear 35 to drive the upper support shaft 32 and the lower support shaft 33 to rotate around their axes.

[0074] Figure 3 In the illustrated embodiment, cams 36 are arranged 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 abutting state between the contour shape of the cam 36 and the follower, thereby adjusting the longitudinal positions of the upper polishing head 21 and the lower polishing head 22.

[0075] In the present invention, the structure and connection relationship of the cam 36 on the upper support shaft 32 are the same as those of the cam 36 on the lower support shaft 33.

[0076] Figure 4 A schematic diagram showing the cam 36 arranged on the upper support shaft 32 is shown. The contour shape of the cam 36 is convex on one side and circular 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 contour determines the motion 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.

[0077] In the present invention, fixing components 50 are arranged at the ends of the upper support shaft 32 and the lower support shaft 33 to respectively fix the upper polishing head 21 and the lower polishing head 22. Since the fixing components 50 arranged on the upper support shaft 32 and the lower support shaft 33 have the same structure, now taking Figure 5 the fixing component 50 arranged on the upper support shaft 32 shown as an example, the structural composition and connection relationship of the fixing component 50 are described.

[0078] The fixing component 50 includes a fixing seat 51 and a support plate 52. As Figure 5 shown, the fixing seat 51 is arranged at the end of the upper support shaft 32. The support plate 52 has an L-shaped structure and is connected to the side of the fixing seat 51 through a slider 53. The upper polishing head 21 is arranged on the support plate 52.

[0079] Furthermore, the fixing seat 51 is provided with a sliding groove 51a. As Figure 6As shown, the sliding groove 51a is a through groove, which is arranged vertically.

[0080] A connecting rod 54 is arranged on the side of the slider 53. Figure 7 As shown, the connecting rod 54 is arranged horizontally and passes through the sliding groove 51a of the fixed seat 51. A transmission roller 55 is arranged at the end of the connecting rod 54. The cam 36 abuts against the transmission roller 55, so as to change the vertical position of the slider 53 fixed by the connecting rod 54 along with the change of the contour of the cam 36, so that the connecting rod 54 on the slider 53 moves along the length direction of the sliding groove 51a, so as 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.

[0081] Figure 7 In the shown embodiment, a transfer rack 56 is arranged at the end of the connecting rod 54. The transfer rack 56 is a U-shaped rack. The transmission roller 55 is rotatably connected to the transfer rack 56 through a rotating shaft.

[0082] Further, 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 as to drive the slider 53 to move up and down through the rotating cam 36, so as to change the vertical position of the support plate 52 and the upper polishing head 21 thereon.

[0083] Wherein, the upper polishing head 21 includes a support block 21a and a backing plate 21b. As Figure 8 shown, the support block 21a is arranged on the side of the support plate 52; that is, the backing plate 21b is stacked on the side of the support block 21a.

[0084] Further, the support block 21a is a trapezoidal block, and the backing plate 21b is arranged above the small cross-section of the trapezoidal block. As Figure 5 shown, it is convenient for the polishing belt 20a to cover the outside of the backing plate 21b without interfering with the edge of the support block 21a, so as to maintain a good use state of the polishing belt treatment.

[0085] In the present invention, the backing plate 21b is made of a plastic non-metallic material, so that the polishing belt outside the backing plate 21b can adapt to the contour of the wafer edge and be completely attached to the surface to be polished of the wafer, so as to obtain a polishing quality meeting the process requirements.

[0086] Further, the length of the backing plate 21b matches the width of the polishing belt, so that the moving polishing belt is continuously in contact with the surface to be processed of the wafer, thereby ensuring the efficiency of wafer edge polishing.

[0087] The polishing belt bypasses the guide rollers 57 arranged on both sides of the backing plate 21b and wraps around the outside of the backing plate 21b. Specifically, the guide rollers 57 are installed on the fixed seats 51 and symmetrically arranged on both sides of the backing plate 21b; the polishing belt 20a bypasses one guide roller 57, the backing plate 21b and the other guide roller 57 in sequence and wraps around the outside of the backing plate 21b.

[0088] Figure 3 In the illustrated embodiment, the horizontal transmission assembly 40 includes a vertical plate 41 and a horizontal actuator 42. Among them, the horizontal actuator 42 is arranged on the side of the vertical plate 41, and its moving end is configured with an edge polishing head 23. The guide roller 57 that defines the polishing belt is arranged on the vertical plate 41, as Figure 3 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 elaborated here.

[0089] It should be noted that the horizontal actuator 42 can be a linear motion module such as a cylinder or an electric cylinder. The edge polishing head 23 is arranged at the moving end of the horizontal actuator 42 to abut the polishing belt covered by the edge polishing head 23 against the edge portion of the wafer, so as to polish the edge portion of the wafer.

[0090] Figure 9 In the illustrated embodiment, the first control wheel 34a and the second control wheel 34b are incomplete gears to control their meshing conditions with the upper gear 35a and the lower gear 35b, thereby adjusting the longitudinal positions of the upper polishing head 21 and the lower polishing head 22.

[0091] Furthermore, the first control wheel 34a is a pair of sector gears, and the sector gears are 1 / 4 of the circumference. Moreover, the two are symmetrically arranged along the center of the circle, that is, the central angle corresponding to the sector gears is 90°; the second control wheel 34b is a semi-circular gear, and its corresponding central angle is 180°.

[0092] Figure 10 is a schematic diagram of the control wheel 34 provided in an embodiment of the present invention arranged on the control shaft 31. The first control wheel 34a and the second control wheel 34b are arranged at intervals along the axial direction of the control shaft 31. Moreover, the first control wheel 34a and the second control wheel 34b are installed with a relatively fixed phase angle on the control shaft 31, so that the timing transmission assembly 30 can at least have the following three states:

[0093] State 1: The first control wheel 34a meshes with the upper gear 35a, and the second control wheel 34b does not mesh with the lower gear 35b;

[0094] State 2: The first control wheel 34a meshes with the upper gear 35a, and the second control wheel 34b meshes with the lower gear 35b;

[0095] State 3: The first control wheel 34a does not mesh with the upper gear 35a, and the second control wheel 34b meshes with the lower gear 35b.

[0096] When the timing drive assembly 30 is in State 1, the first control wheel 34a is only engaged with the upper gear 35a, and the upper support shaft 32 rotates about the axis to abut against the drive 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 covering the outside of the backing plate 21b of the upper polishing head 21 abuts against the upper surface S1 of the wafer Figure 2 (shown in the figure), to polish the upper surface of the edge of the wafer.

[0097] When the timing drive assembly 30 is in State 2, the first control wheel 34a is engaged with the upper gear 35a, and the second control wheel 34b is engaged with the lower gear 35b, to simultaneously control the upper polishing head 21 and the lower polishing head 22 to move towards 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.

[0098] Since the upper polishing head 21 and the lower polishing head 22 simultaneously abut against the upper and lower surfaces of the wafer, the wafer does not warp and deform towards one side, thereby preventing the negative impact of the warping deformation caused by the unilateral processing of the wafer edge on the polishing quality and ensuring the polishing quality of the wafer edge.

[0099] When the timing drive assembly 30 is in State 3, the second control wheel 34b is engaged with the lower gear 35b, and the lower support shaft 33 rotates about the axis to abut against the drive 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 covering the outside of the backing plate 21b of the lower polishing head 22 abuts against the lower surface S2 of the wafer Figure 2 shown in the figure), to polish the lower surface of the edge of the wafer.

[0100] 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 Figure 11 shown in the figure, corresponding to State 2 of the timing drive assembly 30, so that 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.

[0101] It should be noted that the timing drive assembly 30 further has a State 4: 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 simultaneously.

[0102] To achieve the situation of State Four, 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 a 1 / 4 area of the circumference, as Figure 11 shown, so that the control wheel 34 does not mesh with the upper gear 35a and the lower gear 35b.

[0103] It can be understood that when the timing transmission assembly 30 is in State Four, 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.

[0104] According to the second aspect of the embodiments of the present application, a wafer edge polishing method is provided, which uses Figure 1 the wafer edge polishing device 100 shown, and the flowchart of this wafer edge polishing method is as Figure 12 shown, and it includes:

[0105] Step 1, place the wafer to be processed on the tray 11 of the loading and rotating mechanism 10;

[0106] Specifically, an external manipulator 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 and holds the wafer by vacuum adsorption, and drives the tray 11 and the wafer thereon to rotate through the loading and rotating mechanism 10;

[0107] Step 2, the polishing head of the polishing assembly 20 feeds laterally and / or longitudinally, so that the polishing belt abuts against the upper surface, the lower surface and / or the edge of the wafer;

[0108] 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;

[0109] Step 3, the polishing belt moves to polish the upper surface, the lower surface and / or the edge of the wafer.

[0110] After the polishing head moves into place, the polishing belt moves to process the upper surface, the lower surface and / or the edge of the wafer through the polishing belt.

[0111] In step two, two of the polishing heads of the polishing assembly 20 operate simultaneously to polish the edge of the wafer. 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 methods, at least two parts of the upper surface, the lower surface, and the edge part of the wafer edge are subjected to the load applied by the polishing head, which can avoid the off-axis warping of the wafer edge to a certain extent, thereby ensuring the processing quality of the wafer edge.

[0112] When the upper polishing head 21 and the lower polishing head 22 process the edge of the wafer simultaneously, the timing transmission assembly 30 drives the control shaft 31 to rotate, so that the first control wheel 34a meshes with the upper gear 35a, and the second control wheel 34b meshes with the lower gear 35b. Furthermore, 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 polish the upper and lower surfaces of the wafer.

[0113] After the upper and lower surfaces of the wafer are polished, the horizontal transmission assembly 40 controls the horizontal movement of the edge polishing head 23, and the polishing belt thereon abuts against the edge part of the wafer ( Figure 2 shown as S3) to complete the polishing of the edge part of the wafer.

[0114] In some embodiments, there is an overlapping area So (as Figure 13 shown) between the working area of the edge polishing head 23 and the working areas of the upper polishing head 21 and the lower polishing head 22. That is, when the edge polishing head 23 finally processes the edge part of the wafer, it can cover the processing traces left by the upper polishing head 21 and the lower polishing head 22, thereby avoiding the traces left by a single polishing head from affecting the edge polishing effect of the wafer.

[0115] 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 as to eliminate the traces left by the action of a single polishing head through the action of the edge polishing head 23 and ensure the edge polishing effect of the wafer.

[0116] It can be understood that the upper polishing head 21 or the lower polishing head 22 can also process the edge of the wafer alone. When the upper polishing head 21 or the lower polishing head 22 processes the wafer edge alone, the backing plate 21b of the polishing head on the other side abuts against the wafer surface, and the backing plate 21b does not cover the polishing belt. With such a setting, the backing plate 21b of the polishing head on the other side can provide support for the wafer to avoid warping and deformation of the wafer, which affects the edge polishing quality.

[0117] It can be understood that each polishing head of the polishing assembly 20 can simultaneously process the upper surface, lower surface and edge portion of the edge of the wafer. Since there is an interaction between the polishing belts of adjacent polishing heads, finally, the edge polishing head 23 is also required to perform overall processing on the edge portion of the wafer to avoid the traces left by the processing of a single polishing head and ensure the quality of wafer edge polishing.

[0118] Those of ordinary skill in the art can realize that the units and method steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Skilled professionals can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the embodiments of the present application.

[0119] The above embodiments are only used to illustrate the embodiments of the present application, rather than to limit the embodiments of the present application. Those of ordinary skill in the relevant technical field can also 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, and the patent protection scope of the embodiments of the present application should be defined by the claims.

Claims

1. A wafer edge polishing device, characterized in that, Comprising: A loading and rotating mechanism for loading and driving a wafer to rotate around a central axis; A polishing assembly that presses a polishing belt against the edge of the wafer to polish the wafer; The polishing assembly includes an upper polishing head, a lower polishing head, and an edge polishing head, which achieve polishing of the upper surface, lower surface, and / or edge portion of the wafer through lateral and longitudinal feeding; The polishing assembly further 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 feeding of the upper polishing head and the lower polishing head to polish the upper surface and / or lower surface of the edge of the wafer; the horizontal transmission assembly is connected to the edge polishing head to control the lateral feeding of the edge polishing head to polish the edge portion of the wafer.

2. The wafer edge polishing device according to claim 1, wherein 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 axially arranged on the control shaft, which meshes with the gears of the upper support shaft and the lower support shaft to adjust the longitudinal positions of the upper polishing head and the lower polishing head.

3. The wafer edge polishing device according to claim 2, wherein The control shaft is configured with a first control wheel and a second control wheel, which are spaced apart; the first control wheel meshes with the upper gear of the upper support shaft, and the second control wheel meshes 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 positions of the upper polishing head and the lower polishing head.

4. The wafer edge polishing device according to claim 3, wherein, 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.

5. The wafer edge polishing device according to claim 4, characterized in that, The first control wheel is a pair of sector gears, and the sector gears are 1 / 4 of the circumference, and the two are symmetrically arranged along the center; the second control wheel is a semi-circular gear.

6. The wafer edge polishing device according to claim 5, wherein, The timing transmission assembly has at least the following three states: the first control wheel meshes with the upper gear, and the second control wheel does not mesh with the lower gear; the first control wheel meshes with the upper gear, and the second control wheel meshes with the lower gear; the first control wheel does not mesh with the upper gear, and the second control wheel meshes with the lower gear.

7. The wafer edge polishing device according to claim 6, wherein, One sector gear of the first control wheel overlaps with the second control wheel in the circumferential direction.

8. The wafer edge polishing device according to claim 6, wherein, The first control wheel and the second control wheel do not overlap completely in a 1 / 4 region of the circumference.

9. The wafer edge polishing device according to claim 3, characterized in that, The ends of the upper support shaft and the lower support shaft are configured with a fixing assembly, which includes a fixing seat and a support plate. The support plate is connected to the fixing seat through a slider, and the upper polishing head and the lower polishing head are configured on the support plate.

10. The wafer edge polishing device according to claim 9, characterized in that, The fixing seat is configured with a vertical sliding groove, and a lateral connecting rod is configured on the side of the slider. The connecting rod passes through the sliding 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 slider moves along the length direction of the sliding groove to change the position of the support plate.

11. The wafer edge polishing device according to claim 10, wherein A transfer frame is configured at the end of the connecting rod. The transfer frame is a U-shaped frame, and the transmission roller is rotatably connected to the transfer 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.

12. The wafer edge polishing device according to claim 9, wherein, The upper polishing head and the lower polishing head include a support block and a backing plate. The support block is disposed on the support plate, and the backing plate is stacked on the support block. The polishing belt bypasses guide rollers disposed on both sides of the backing plate and wraps around the outside of the backing plate.

13. The wafer edge polishing device according to claim 12, wherein, The support block is a trapezoidal block, and the backing plate is disposed above the small cross-section of the trapezoidal block.

14. The wafer edge polishing device according to claim 12, wherein, The backing plate is made of a plastic non-metallic material, and its length matches the width of the polishing belt.

15. The wafer edge polishing device according to claim 1, wherein, The horizontal transmission assembly includes a vertical plate and a horizontal actuator. The horizontal actuator is disposed on the side of the vertical plate, and its moving end is configured with an edge polishing head. The edge polishing head has the same structure as the upper polishing head and the lower polishing head.

16. A wafer edge polishing method, characterized in that, Using the wafer edge polishing device according to any one of claims 1-15, comprising: Step 1, placing the wafer to be processed on the tray of the loading and rotating mechanism; Step 2, the polishing heads of the polishing assembly are fed horizontally and / or longitudinally, so that the polishing belt abuts against the upper surface, the lower surface and / or the edge portion of the wafer; Step 3, the polishing belt moves to polish the upper surface, the lower surface and / or the edge portion of the wafer.

17. The wafer edge polishing method according to claim 16, wherein Two of the polishing heads of the polishing assembly operate simultaneously to polish the edge of the wafer.

18. The wafer edge polishing method according to claim 16, wherein When the upper polishing head or the lower polishing head processes the wafer edge alone, the backing plate of the polishing head on the other side abuts against the wafer surface, and the backing plate does not wrap the polishing belt.

19. The wafer edge polishing method according to claim 16, wherein The timing transmission assembly drives the control shaft to rotate, so that the first control wheel meshes with the upper gear, and the second control wheel meshes with the lower gear. Further, the polishing belts of the upper polishing head and the lower polishing head respectively abut against the upper and lower surfaces of the wafer to polish the upper and lower surfaces of the wafer.

20. The wafer edge polishing method according to claim 19, wherein, After the upper and lower surfaces of the wafer are polished, the horizontal transmission assembly controls the horizontal movement of the edge polishing head, and the polishing belt thereon abuts against the edge portion of the wafer to complete the polishing of the edge portion of the wafer.

21. The wafer edge polishing method according to claim 16, wherein There is an overlapping part between the working area of the edge polishing head and the working areas of the upper polishing head and the lower polishing head.

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