Wafer edge polishing system

Abstract

The utility model 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] Embodiments of the present application relate to the technical field of semiconductor manufacturing, and in particular, to a wafer edge polishing system. BACKGROUND

[0002] In the existing wafer processing technology, after the wafer is processed by multiple processes such as etching, the edge of the wafer is prone to have sharp burrs, or the thickness of the wafer edge is not uniform, which causes uneven stress in subsequent processing and leads to wafer cracking, affecting the yield.

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

[0004] The existing wafer edge polishing system is usually a simple edge polishing, but a large amount of fine particles will be generated during the edge polishing process, which will adhere to the edge of the wafer and increase the difficulty of cleaning in the later stage if not cleaned in time.

[0005] At the same time, the existing wafer edge polishing mechanism has only one polishing head, and the entire polishing process is completed by multiple flips of the single polishing head. During the edge polishing process of the wafer, the upper and lower surface polishing and edge polishing of the wafer need to be completed, and 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 needs to occupy a large 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.

[0006] In addition, during the edge upper and lower surface polishing, the polishing positive pressure of the single polishing head on the wafer will cause the wafer to deform and affect the polishing effect of the wafer, and may cause the wafer to crack. CONTENT OF THE INVENTION

[0007] Therefore, embodiments of the present application provide a wafer edge polishing system to at least partially solve the above problems.

[0008] According to embodiments of the present application, a wafer edge polishing system is provided, which comprises:

[0009] a front-end unit;

[0010] a polishing unit arranged adjacent to the front-end unit, which at least comprises a wafer edge polishing device;

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

[0012] The wafer edge polishing device comprises:

[0013] a loading and rotating mechanism for loading and driving the wafer to rotate around a central axis;

[0014] A polishing assembly presses a polishing belt against the edge of a wafer to polish the wafer.

[0015] The polishing assembly comprises an upper polishing head, a lower polishing head and an edge polishing head, which polish the upper surface, the lower surface and / or the edge of the wafer through horizontal and vertical feeding.

[0016] In some embodiments, the polishing assembly further comprises a timing transmission assembly and a horizontal transmission assembly, the timing transmission assembly is connected with the upper polishing head and the lower polishing head to control the vertical 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 to control the horizontal feeding of the edge polishing head to polish the edge of the wafer.

[0017] In some embodiments, the wafer edge polishing system further comprises a polishing transmission robot, which is arranged between the polishing unit and the cleaning unit, and is provided with a sliding rail arranged along the length direction of the wafer edge polishing system to transport the wafer inside the polishing unit.

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

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

[0020] In some embodiments, the wafer edge polishing system further comprises a buffer module, which is arranged between the wafer edge polishing device and the cleaning unit to buffer the wafer after polishing.

[0021] In some embodiments, the buffer module is arranged adjacent to the cleaning unit.

[0022] In some embodiments, the number of the cleaning module and the drying module is at least two groups, which are arranged in vertical stacking.

[0023] In some embodiments, the timing transmission assembly comprises a control shaft, an upper support shaft fixing the upper polishing head and a lower support shaft fixing the lower polishing head, which are arranged transversely, and the control shaft is arranged between the upper support shaft and the lower support shaft; the control shaft is provided with a control wheel in the axial direction, which is engaged with the gears of the upper support shaft and the lower support shaft to adjust the vertical position of the upper polishing head and the lower polishing head.

[0024] In some embodiments, the control shaft is configured with a first control wheel and a second control wheel, which are arranged in a spaced manner; 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, so as to drive the rotation of the cam 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.

[0025] In some embodiments, the first control wheel and the second control wheel are incomplete gears, so as to control the engagement of the first control wheel and the second control wheel with the upper gear and the lower gear, thereby adjusting the longitudinal position of the upper polishing head and the lower polishing head.

[0026] 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 sector gears are arranged in a central symmetry manner; the second control wheel is a semicircular gear.

[0027] In some embodiments, the timing transmission assembly 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.

[0028] In some embodiments, the end of the upper support shaft and the lower support shaft is configured with a fixing assembly, the fixing assembly comprises a fixing seat and a support plate, the support plate is connected to the fixing seat through a sliding block, and the upper polishing head and the lower polishing head are arranged on the support plate.

[0029] In some embodiments, the fixing seat is configured with a vertical sliding groove, the side of the sliding block is configured with a transverse connecting rod, the connecting rod is arranged through the sliding groove, and the side of the connecting rod is configured with a transmission roller; the cam of the upper support shaft and the lower support shaft is in abutment with the transmission roller, so that the connecting rod on the sliding block moves along the length direction of the sliding groove, so as to change the position of the support plate.

[0030] In some embodiments, the end of the connecting rod is configured with an adapter frame, the adapter frame is a U-shaped frame, and the transmission roller is rotationally 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 is in abutment with the profile surface of the cam.

[0031] In some embodiments, the upper polishing head and the lower polishing head comprise a support block and a pad plate, the support block is arranged on the support plate, and the pad plate is arranged on the support block; the polishing belt passes through the guide rollers arranged on both sides of the pad plate and is wrapped on the outside of the pad plate.

[0032] In some embodiments, the support block is a trapezoidal block, and the pad plate is arranged above the small cross section of the trapezoidal block.

[0033] In some embodiments, the backing plate is made of a plastic non-metallic material, and the length of the backing plate matches the width of the polishing belt.

[0034] In some embodiments, the horizontal transmission assembly comprises a vertical plate and a horizontal actuator, the horizontal actuator is arranged at the side of the vertical plate, and the moving end of the horizontal actuator is provided with an edge polishing head; the edge polishing head has the same structure as the upper polishing head and the lower polishing head.

[0035] The beneficial effects of the utility model include:

[0036] a. The wafer edge polishing system provided by the utility model is configured with multiple wafer edge polishing devices to independently work and improve the flexibility of system operation;

[0037] b. The cleaning unit of the wafer edge polishing system comprises a cleaning module and a drying module, and each functional module is arranged in a vertical stack to reduce the floor area;

[0038] c. The polishing transmission manipulator is arranged between the wafer edge polishing device and the cleaning unit, and the polishing transmission manipulator is arranged between the pre-positioning module and the buffer module to consider the transmission between each functional module;

[0039] d. The wafer edge polishing device is configured with independent upper polishing heads, lower polishing heads and edge polishing heads, which can be fed horizontally and / or vertically to polish the edge of the wafer and improve the flexibility of edge processing;

[0040] e. The upper polishing heads, the lower polishing heads and the edge polishing heads of the polishing assembly do not need to process the edge of the wafer by swinging around a fixed point, which simplifies the structure of the polishing assembly and is beneficial to ensuring the stability of the operation of the polishing assembly;

[0041] f. The upper polishing heads, the lower polishing heads and the edge polishing heads can be combined to process the edge of the wafer, the wafer does not exist unilateral warping deformation, and then the negative influence of the warping deformation caused by unilateral processing of the edge of the wafer on the polishing quality is prevented, and the polishing quality of the edge of the wafer is ensured;

[0042] g. The working area of the edge polishing head overlaps the working area of the upper polishing head and the lower polishing head. That is, when the edge polishing head processes the edge of the wafer, it can cover the processing marks left by the upper polishing head and the lower polishing head, and then the marks left by a single polishing head are avoided to affect the polishing effect of the edge of the wafer;

[0043] h. The polishing assembly is configured with a time sequence transmission assembly, which can control the longitudinal position of the upper polishing head and the lower polishing head to selectively process the upper and lower surfaces of the wafer;

[0044] i. The first control wheel and the second control wheel of the timing transmission assembly are fixed in phase angle on the control shaft, so as to change the running state of the upper polishing head and the lower polishing head by driving the control wheel to rotate;

[0045] j. The first control wheel and the second control wheel are incomplete gears, so as to control the meshing state of the upper gear and the lower gear, and further adjust the longitudinal position of the upper polishing head and the lower polishing head;

[0046] k. The upper support shaft and the lower support shaft are provided with cams, the cams abut against transmission rollers connected with 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 abuts against the specific work area of the wafer edge;

[0047] l. The wafer edge polishing system provided by the application is provided with a cleaning unit, so that cleaning operation can be carried out after wafer edge polishing without circulating to other equipment, so as to avoid long-time adhesion of particle pollutants, and facilitate to reduce the difficulty of removing pollutants. BRIEF DESCRIPTION OF DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art according to these drawings.

[0049] Figure 1 is a schematic diagram of a wafer edge polishing system provided by an embodiment of the application;

[0050] Figure 2 is a schematic diagram of a wafer edge polishing device provided by an embodiment of the application;

[0051] Figure 3 is a schematic diagram of a work area corresponding to the wafer edge processed by the polishing head;

[0052] Figure 4 is a schematic diagram of a polishing assembly provided by an embodiment of the application;

[0053] Figure 5 is a schematic diagram of the cam provided on the upper support shaft;

[0054] Figure 6 is a schematic diagram of the connection between the upper support shaft and the upper polishing head;

[0055] Figure 7 is a schematic diagram of a fixing seat provided by an embodiment of the application;

[0056] Figure 8 is a schematic view of a fixing assembly of a fixed seat provided by an embodiment of the present application;

[0057] Figure 9 is a schematic view of an upper polishing head provided by an embodiment of the present application;

[0058] Figure 10 is a schematic view of a polishing assembly in Figure 4

[0059] Figure 11 is a schematic view of a control wheel provided on a control shaft provided by an embodiment of the present application;

[0060] Figure 12 is a side view of a first control wheel and a second control wheel provided on the control shaft;

[0061] Figure 13 is a schematic view of an overlapping area of a wafer edge provided by an embodiment of the present application;

[0062] Figure 14 is a schematic view of a brushing module provided by an embodiment of the present application;

[0063] Figure 15 is a schematic view of a drying module provided by an embodiment of the present application;

[0064] Figure 16 is a schematic view of a cleaning unit provided by an embodiment of the present application. DETAILED DESCRIPTION

[0065] In order to make personnel in the art 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 some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art should belong to the scope of protection of the embodiments of the present application.

[0066] The terms used in the present application are merely for the purpose of describing particular embodiments and are not intended to limit the present application. The singular forms "a", "said" and "the" 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" used herein means and includes any or all possible combinations of one or more associated listed items.

[0067] ​It should be understood that, although the terms "first", "second", "third", etc. can be used in this application to describe various information, these 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, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information without departing from the scope of the application. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0068] Figure 1 The utility model relates to a kind of wafer edge polishing systems 1000, its schematic diagram, as shown in Figure 1 Wafer edge polishing system 1000 includes:

[0069] Front-end unit 200, for storing the wafer to be polished and the wafer after polishing, is internally configured with front-end manipulator 210, to transmit the wafer in the wafer loading box of front-end unit 200 to each functional module, and is responsible for transmitting the wafer after polishing and cleaning to the wafer loading box of front-end unit 200;

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

[0071] Cleaning unit 300, for cleaning and drying wafer surface.

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

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

[0074] Specifically, the polishing transfer robot 410 is configured with a transversely arranged slide rail to increase its horizontal span and expand the range of the robot's grabbing; 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 condition of the functional modules being stacked vertically, and improve the flexibility of wafer transfer.

[0075] Figure 1 In the embodiment shown, the wafer edge polishing system 1000 further comprises a pre-positioning module 500 arranged between the front-end unit 200 and the polishing transfer robot 410 to pre-position the wafer to be processed. For example, the notch of the wafer is positioned to accurately control the feed of each polishing head of the polishing assembly 20 to achieve precise edge polishing.

[0076] Further, the wafer edge polishing system 1000 further comprises a buffer module 600 arranged between the wafer edge polishing device 100 and the cleaning unit 300 to buffer the wafer that has completed polishing. The buffer module 600 generally comprises a plurality of buffer layers arranged vertically stacked to simultaneously buffer a plurality of wafers. Meanwhile, the buffer module 600 is configured with a moisturizing assembly, such as an upper nozzle and a lower nozzle arranged on the buffer layer, to spray deionized water, ozone water, etc. toward the wafer to moisturize the wafer.

[0077] In the utility model, the pre-positioning module 500 and the buffer module 600 are arranged along the longitudinal direction close to the cleaning unit, which is beneficial to prevent the polishing transfer robot 410 from interfering with the pre-positioning module 500 and the buffer 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 buffer 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 further comprises a detection module 700 arranged at the end of the front-end unit 200 to detect the wafer before and after polishing, and thus 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, i.e. the wafer edge polishing device 100, will be described in detail below. The wafer edge polishing device 100 comprises:

[0080] A loading rotation mechanism 10 for loading and driving the wafer W to rotate around the central axis;

[0081] A polishing assembly 20 for pressing the polishing belt 20a (shown in the figure) against the edge of the wafer to achieve wafer polishing. Figure 6

[0082] ​Further, the loading rotation mechanism 10 comprises a tray 11, which is indicated by a dashed line, and a rotary motor is arranged below the tray 11, and the rotary motor drives the tray and the wafer W on the tray to rotate around a central axis. Since the wafer W is concentrically arranged above the tray of the loading rotation mechanism 10, it can also be said that the loading rotation mechanism drives the wafer to rotate around the central axis of the loading rotation mechanism. The inside of the tray is provided with a groove / channel, which is connected with a vacuum source through a pipeline, so as to form a negative pressure between the tray and the wafer W, and then the wafer W to be polished is adsorbed on the upper surface of the tray.

[0083] Figure 2 The polishing assembly 20 comprises an upper polishing head 21, a lower polishing head 22 and an edge polishing head 23, which are fed in the transverse and longitudinal directions to realize polishing of the upper surface S1, the lower surface S2 and / or the edge portion S3 of the wafer. Figure 3 The various operation areas of the wafer edge polishing are shown, and the edge polishing can remove the corners of the wafer edge to eliminate the stress concentration caused by the corners, so that the wafer edge becomes round.

[0084] In the utility model, the polishing assembly 20 further comprises a time sequence transmission assembly 30, which is connected with 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, and then the upper surface and / or the lower surface of the wafer edge are processed.

[0085] Further, the polishing assembly 20 further comprises a horizontal transmission assembly 40, which is connected with the edge polishing head 23 to control the transverse feeding of the edge polishing head 23, and then the edge portion of the wafer is processed.

[0086] Figure 4 It is the schematic view of the polishing assembly 20 provided by an embodiment of the utility model, wherein the time sequence transmission assembly 30 comprises a control shaft 31, an upper support shaft 32 and a lower support shaft 33, which are arranged parallel to the horizontal plane, wherein the upper support shaft 32 is used for fixing the upper polishing head 21, the lower support shaft 33 is used for fixing the lower polishing head 22, and the control shaft 31 is arranged transversely between the upper support shaft 32 and the lower support shaft 33.

[0087] Further, the control shaft 31 is provided with control wheels 34, the number of the control wheels 34 is two, namely a first control wheel 34a and a second control wheel 34b, which are arranged along the axial direction of the control shaft 31, and the control wheels 34 are 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 disposed on the upper support shaft 32, and its position is opposite to the first control wheel 34a on the control shaft 31 so that the first control wheel 34a meshes with the upper gear 35a; correspondingly, a lower gear 35b is disposed on the lower support shaft 33, and its position is opposite to the second control wheel 34b on the control shaft 31 so that the second control wheel 34b meshes with the lower gear 35b.

[0089] It should be noted that the outer circumferential surface of the control wheel 34 is equipped with teeth that mesh with the gear 35. Figure 4 The general shape of the control wheel 34 is only shown schematically; 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.

[0090] Figure 4 In the embodiment shown, cams 36 are 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 contact state with the follower, thereby adjusting the longitudinal position of the upper polishing head 21 and the lower polishing head 22.

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

[0092] Figure 5 A schematic diagram shows a cam 36 mounted on an upper support shaft 32. The cam 36 has a profile that is convex on one side and circular on the opposite side, with a relatively smooth transition between the two. The cam 36 rotates around the upper support shaft 32, and the shape of its outer profile determines the motion pattern of the follower. The follower here is the drive roller 55 mentioned below, which can drive the upper polishing head 21 to move vertically, thereby changing its longitudinal position.

[0093] In this invention, the ends of the upper support shaft 32 and the lower support shaft 33 are equipped with fixing components 50 to fix the upper polishing head 21 and the lower polishing head 22, respectively. Since the fixing components 50 on the upper support shaft 32 and the lower support shaft 33 have the same structure, they will now be used as... Figure 6 Taking the fixed component 50 set on the upper support shaft 32 as an example, the structural composition and connection relationship of the fixed component 50 are explained.

[0094] The fixing component 50 includes a fixing base 51 and a support plate 52, such as Figure 6 As shown, the fixed seat 51 is located at the end of the upper support shaft 32, the support plate 52 has an L-shaped structure, and it is connected to the side of the fixed seat 51 by a slider 53. The upper polishing head 21 is located on the support plate 52.

[0095] Furthermore, the fixed base 51 is provided with a sliding groove 51a, such as Figure 7As shown, the sliding groove 51a is a through groove, which is arranged vertically.

[0096] The sliding block 53 is arranged laterally Figure 8 The connecting rod 54 is shown, which is arranged transversely and passes through the sliding groove 51a of the fixing base 51, and the end of the connecting rod 54 is arranged with a transmission roller 55, which abuts against the cam 36, so as to change the vertical position of the sliding block 53 fixed by the connecting rod 54 along with the contour change of the cam 36, so that the connecting rod 54 on the sliding block 53 moves along the length direction of the sliding groove 51a, so as to change the position of the support plate 52, that is, the longitudinal position of the support plate 52 and the upper polishing head 21 thereon.

[0097] Figure 8 In the embodiment shown, the end of the connecting rod 54 is arranged with an adapter frame 56, which is a U-shaped frame, and the transmission roller 55 is rotationally connected to the adapter frame 56 through a rotating shaft.

[0098] 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 sliding block 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.

[0099] Among them, the upper polishing head 21 includes a support block 21a and a pad plate 21b, as Figure 9 As shown, the support block 21a is arranged laterally to the support plate 52; that is, the pad plate 21b is stacked laterally to the support block 21a.

[0100] Further, the support block 21a is a trapezoidal block, and the pad plate 21b is arranged above the small section of the trapezoidal block, as Figure 6 As shown, so that the polishing belt 20a is wrapped outside the pad plate 21b without interference with the edge of the support block 21a, thereby maintaining the use state of the polishing belt in good condition.

[0101] In the utility model, the pad plate 21b is made of plastic non-metallic material, so that the polishing belt outside the pad plate 21b can adapt to the contour of the wafer edge and completely match the polishing surface of the wafer, so as to obtain the polishing quality meeting the process requirements.

[0102] Further, the length of the pad plate 21b matches the width of the polishing belt, so that the moving polishing belt continuously contacts the machining surface of the wafer, thereby ensuring the efficiency of polishing the wafer edge.

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

[0104] Figure 4 In the illustrated embodiment, the horizontal transmission assembly 40 includes a vertical plate 41 and a horizontal actuator 42, wherein the horizontal actuator 42 is arranged at the side of the vertical plate 41, the moving end of the horizontal actuator 42 is configured with the edge polishing head 23, and the guide rollers 57 for limiting the polishing belt are arranged on the vertical plate 41, as shown in the figure. 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, which will not be described here.

[0105] It should be noted that the horizontal actuator 42 can be a linear motion module such as a pneumatic cylinder or an electric cylinder, and 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 to the edge portion of the wafer to polish the edge portion of the wafer.

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

[0107] Further, the first control wheel 34a 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, that is, the central angle corresponding to the sector gears is 90°; the second control wheel 34b is a semicircular gear, and the central angle corresponding to the second control wheel 34b is 180°.

[0108] Figure 11 is a schematic view of the control wheel 34 provided by an embodiment of the utility model and 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, and the first control wheel 34a and the second control wheel 34b are fixed in phase angle on the control shaft 31, so that the time sequence transmission assembly 30 can exist at least in the following three states:

[0109] State one: 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 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;

[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 one, the first control wheel 34a is only engaged with the upper gear 35a, and the upper support shaft 32 rotates around the axis to abut the transmission roller 55 through the cam 36, so that the upper polishing head 21 changes its position along with the vertical movement of the support plate 52, and the polishing belt wrapped outside the pad plate 21b of the upper polishing head 21 abuts the upper surface S1 of the wafer edge (as shown), so as to polish the upper surface of the wafer edge. Figure 3

[0113] When the timing transmission assembly 30 is in state two, 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, so as to control the upper polishing head 21 and the lower polishing head 22 to move towards the wafer at the same time, so that the corresponding polishing belts abut the upper surface and the lower surface of the wafer edge, so as to polish the upper and lower surfaces of the wafer edge.

[0114] Since the upper polishing head 21 and the lower polishing head 22 abut the upper and lower surfaces of the wafer at the same time, the wafer does not exist the deformation of warping towards a single side, and further, the negative influence of the warping deformation caused by the single side processing of the wafer edge on the polishing quality is prevented, and the polishing quality of the wafer edge is ensured.

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

[0116] In the utility model, when the control wheel 34 is fixed to the control shaft 31, one sector gear of the first control wheel 34a overlaps the second control wheel 34b in the circumferential direction, as shown, so as to correspond to state two of the timing transmission assembly 30, so that the two control wheels 34 are engaged with the upper gear 35a and the lower gear 35b respectively, so as to control the upper polishing head 21 and the lower polishing head 22 to polish the wafer edge at the same time. Figure 12

[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 wafer edge at the same time.

[0118] ​​​In order to realize the 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 are completely not overlapped in the 1 / 4 area of the circumference, as shown in the figure, so that the control wheel 34 is not engaged with the upper gear 35a and the lower gear 35b. Figure 12

[0119] It can be understood that when the timing transmission assembly 30 is in the 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.

[0120] The following will be described in detail the operation process of the wafer edge polishing device 100: Figure 2

[0121] Step one, place the wafer to be processed on the tray 11 of the loading rotation mechanism 10;

[0122] Specifically, the external mechanical arm transmits the wafer to be processed to the tray 11 of the loading rotation 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 is attracted by vacuum adsorption and rotates with the wafer on the tray 11 by the loading rotation mechanism 10;

[0123] Step two, the polishing head of the polishing assembly 20 is fed transversely and / or longitudinally, so that the polishing belt abuts against the upper surface, the lower surface and / or the edge of the wafer;

[0124] Specifically, the polishing assembly 20 controls the transverse 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 realize the polishing of the upper surface, the lower surface and / or the 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 of the wafer by the polishing belt.

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

[0128] ​​When the upper polishing head 21 and the lower polishing head 22 simultaneously polish the edge of the wafer, the timing transmission assembly 30 drives the control shaft 31 to rotate, so that 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, and then the polishing belts of the upper polishing head 21 and the lower polishing head 22 are respectively abutted on the upper and lower surfaces of the wafer, so as to realize the 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 horizontal movement of the edge polishing head 23, and the polishing belt on the edge polishing head 23 is abutted on the edge of the wafer (as shown in S3), so as to complete the polishing of the edge of the wafer. Figure 3

[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 (as shown in S4). Figure 13 That is, when the edge polishing head 23 finishes polishing the edge of the wafer, it can cover the polishing traces left by the upper polishing head 21 and the lower polishing head 22, so as to avoid the influence of the traces left by a single polishing head on the polishing effect of the edge of the wafer.

[0131] In the utility model, 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 a single polishing head can be eliminated by the edge polishing head 23, and the polishing effect of the edge of the wafer is ensured.

[0132] It can be understood that the upper polishing head 21 or the lower polishing head 22 can also polish the edge of the wafer alone. When the upper polishing head 21 or the lower polishing head 22 polishes the edge of the wafer alone, the pad 21b of the polishing head on the other side is abutted on the surface of the wafer, and the pad 21b is not covered by the polishing belt. In this way, the pad 21b of the polishing head on the other side can provide support for the wafer, so as to avoid the wafer from being deformed and affecting the polishing quality of the edge.

[0133] It can be understood that the polishing heads of the polishing assembly 20 can simultaneously polish the upper surface, the lower surface and the edge of the wafer. Due to the mutual influence of the polishing belts of the adjacent polishing heads, the edge polishing head 23 is finally used to polish the edge of the wafer as a whole, so as to avoid the traces left by a single polishing head and ensure the polishing quality of the edge of the wafer.

[0134] In the utility model, the cleaning unit 300 comprises a cleaning module 310 and a drying module 320, and the two are arranged in parallel (as shown in S5). Figure 1 The drying module 320 is arranged close to the front end unit 200. This is because the wafer is clean after drying, and the transmission path of the wafer needs to be shortened to maintain the cleanliness of the surface of the wafer.

[0135] ​The utility model discloses a cleaning module 310 is brush washing module, its schematic diagram, as shown in Figure 14 The wafer is horizontally clamped and rotated by a driving mechanism, and the upper and lower surfaces of the wafer are provided with cleaning brushes to remove the pollutants remaining on the surface of the wafer.

[0136] The drying module 320 is a horizontal drying module, and its schematic diagram is shown in Figure 15 The drying module 320 is based on the Malan Goni effect to peel off the water film on the surface of the wafer, and then obtain the wafer with clean surface.

[0137] In some embodiments, the number of cleaning module 310 and drying module 320 is two groups, which are arranged in vertical stacking, as shown in Figure 16 In order to reduce the floor area of the device, and then arrange multiple cleaning and drying modules in a relatively small space, and then improve the cleaning capacity of the wafer edge polishing system.

[0138] Figure 1 In the embodiment shown, the dashed line with arrow indicates a transmission path of the wafer in the wafer edge polishing system 1000, and the transmission process of the wafer in this embodiment is briefly described as follows:

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

[0140] Then, the polishing transmission manipulator 410 transmits the wafer to one wafer edge polishing device 100 to polish the wafer edge using the polishing assembly 20; then, the polishing transmission manipulator 410 transfers the wafer from one wafer edge polishing device 100 to another wafer edge polishing device 100 to polish the wafer edge;

[0141] When the wafer completes the edge polishing, the polishing transmission manipulator 410 transfers the wafer to the buffer module 600;

[0142] Then, the cleaning transmission manipulator 420 or the polishing transmission manipulator 410 close to the buffer module 600 transmits the wafer to the cleaning unit 300 to clean the wafer;

[0143] Then, the cleaning transmission manipulator 420 arranged between the cleaning module 310 and the drying module 320 transmits the wafer to the drying module 320 to dry the wafer;

[0144] Finally, when the wafer completes the drying, the front end manipulator 210 transmits the dried wafer to the wafer loading box of the front end unit 200.

[0145] Those skilled in the art can understand that the units and method steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software manner depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered as beyond the scope of the embodiments of the present application.

[0146] The above embodiments are only used to illustrate but not to limit the embodiments of the present application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of the present application, and all equivalent technical solutions belong to the scope of the embodiments of the present application. The patent protection scope of the embodiments of the present application should be defined by the claims.

Claims

1. A wafer edge polishing system, comprising: The application relates to a wafer edge polishing system, which comprises: a front-end unit; a polishing unit arranged adjacent to the front-end unit, which at least comprises a 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 for loading and rotating the wafer around a central axis; a polishing assembly for pressing a polishing belt against the edge of the wafer to polish the wafer; the polishing assembly comprises an upper polishing head, a lower polishing head and an edge polishing head, which are fed in the horizontal and vertical directions to polish the upper surface, the lower surface and / or the edge of the wafer.

2. The wafer edge polishing system of claim 1, wherein, The polishing assembly further comprises a timing transmission assembly and a horizontal transmission assembly; the timing transmission assembly is connected with the upper polishing head and the lower polishing head to control the vertical feeding of the upper polishing head and the lower polishing head to polish the upper surface and / or the lower surface of the wafer edge; the horizontal transmission assembly is connected with the edge polishing head to control the horizontal feeding of the edge polishing head to polish the edge of the wafer.

3. The wafer edge polishing system of claim 1, wherein, The polishing system further comprises a polishing transmission robot arranged between the polishing unit and the cleaning unit, which is provided with a sliding rail arranged along the length direction of the wafer edge polishing system to transport the wafer in the polishing unit.

4. The wafer edge polishing system of claim 1, wherein, The cleaning unit comprises a cleaning module, a drying module and a cleaning transmission robot; the cleaning module and the drying module are arranged in parallel, and the drying module is arranged adjacent to the front-end unit; the cleaning transmission robot is arranged adjacent to the cleaning module and the drying module.

5. The wafer edge polishing system of claim 3, wherein, The polishing system further comprises a pre-positioning module arranged between the front-end unit and the polishing transmission robot to pre-position the wafer to be processed.

6. The wafer edge polishing system of claim 1, wherein, The polishing system further comprises a buffer module arranged between the wafer edge polishing device and the cleaning unit to buffer the polished wafer.

7. The wafer edge polishing system of claim 6, wherein, The buffer module is arranged adjacent to the cleaning unit.

8. The wafer edge polishing system of claim 4, wherein, The number of the cleaning module and the drying module is at least two groups, which are arranged in vertical layers.

9. The wafer edge polishing system of claim 2, wherein, The timing transmission assembly comprises a control shaft, an upper supporting shaft for fixing the upper polishing head and a lower supporting shaft for fixing the lower polishing head, which are arranged in the horizontal direction, and the control shaft is arranged between the upper supporting shaft and the lower supporting shaft; the control shaft is provided with a control wheel arranged in the axial direction, which is engaged with the gears of the upper supporting shaft and the lower supporting shaft to adjust the vertical position of the upper polishing head and the lower polishing head.

10. The wafer edge polishing system of claim 9, wherein, The control shaft is provided with a first control wheel and a second control wheel, which are arranged in the interval; the first control wheel is engaged with the upper gear of the upper supporting shaft, and the second control wheel is engaged with the lower gear of the lower supporting shaft to drive the rotation of the cams of the upper supporting shaft and the lower supporting shaft, thereby changing the vertical position of the upper polishing head and the lower polishing head.

11. The wafer edge polishing system of claim 10, wherein, The first control wheel and the second control wheel are incomplete gears to control the engagement with the upper gear and the lower gear, thereby adjusting the vertical position of the upper polishing head and the lower polishing head.

12. The wafer edge polishing system of claim 11, wherein, The first control wheel is a pair of sector gears, which are 1 / 4 of the circumference and are arranged in the center symmetry; the second control wheel is a semicircular gear.

13. The wafer edge polishing system of claim 12, wherein, The timing transmission assembly has at least 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.

14. The wafer edge polishing system of claim 10, wherein, Ends of the upper support shaft and the lower support shaft are provided with a fixing assembly, which comprises a fixing seat and a support plate, the support plate is connected to the fixing seat through a sliding block, and the support plate is provided with an upper polishing head and a lower polishing head.

15. The wafer edge polishing system of claim 14, wherein, The fixing seat is provided with a vertical sliding groove, the sliding block is provided with a transverse connecting rod, the connecting rod is arranged through the sliding groove, and the connecting rod is provided with a transmission roller on the side thereof; the cam provided on the upper support shaft and the lower support shaft abuts against the transmission roller, so that the connecting rod on the sliding block moves along the length direction of the sliding groove, so as to change the position of the support plate.

16. The wafer edge polishing system of claim 15, wherein, 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 is matched with the setting position of the cam, so that the surface of the transmission roller abuts against the profile surface of the cam.

17. The wafer edge polishing system of claim 14, wherein, The upper polishing head and the lower polishing head comprise a support block and a pad, the support block is arranged on the support plate, and the pad is arranged on the support block; the polishing belt passes through the guide rollers arranged on both sides of the pad and is wrapped on the outer side of the pad.

18. The wafer edge polishing system of claim 17, wherein, The support block is a trapezoidal block, and the pad is arranged above the small section of the trapezoidal block.

19. The wafer edge polishing system of claim 17, wherein, The pad is made of plastic non-metallic material, and the length of the pad is matched with the width of the polishing belt.

20. The wafer edge polishing system of claim 2, wherein, The horizontal transmission assembly comprises a vertical plate and a horizontal actuator, the horizontal actuator is arranged on the side of the vertical plate, and the moving end of the horizontal actuator is provided with an edge polishing head; the edge polishing head has the same structure as the upper polishing head and the lower polishing head.

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