Wafer edge processing device

Abstract

The present invention discloses a wafer edge processing device, comprising: a lifting assembly connected to a support frame in a wafer thinning device; a servo rotation assembly connected to the lifting assembly; a processing assembly connected to the bottom of the servo rotation assembly, which includes a chassis, and the bottom surface of the chassis is provided with an arc-shaped grinding and polishing part and a nozzle; and a gas-liquid joint connected to the nozzle through a gas-liquid path inside the processing assembly.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing equipment, and in particular to a wafer edge processing device. Background Art

[0002] The integrated circuit manufacturing process is typically divided into silicon wafer fabrication, front-end processing, and back-end processing. The primary purpose of the back-end process is to transform the entire wafer containing the circuit components into individual finished chips. The back-end process can be broadly divided into eight key steps: backside thinning, wafer dicing, wafer mounting, wire bonding, plastic encapsulation, laser printing, rib cutting and forming, and finished product testing. Backside grinding involves high-precision grinding of various materials, such as silicon wafers or compound semiconductors, prior to packaging, to reduce their thickness to a desired ultra-thin form.

[0003] The thinning equipment integrates the functional components of grinding and chemical mechanical polishing (CMP). The grinding process will thin the back of the wafer to a lower level, such as about 10μm. The edge of this extremely thin wafer is prone to breakage during the grinding and CMP processes. That is to say, crystal peeling will occur at the edge of the wafer, resulting in debris (commonly known as edge fragments). Especially in the CMP process, in order to improve efficiency, the polishing process will be maintained at a higher removal rate. Under high pressure, the wafer edge peeling debris will remain on the polishing pad, which can easily cause scratches on the wafer and even fragments and waste. Summary of the Invention

[0004] An embodiment of the present invention provides a wafer edge processing device, which aims to solve at least one of the technical problems existing in the prior art.

[0005] An embodiment of the present invention provides a wafer edge processing device, comprising:

[0006] A lifting assembly connected to a support frame in the wafer thinning equipment;

[0007] a servo rotating assembly connected to the lifting assembly;

[0008] A processing assembly is connected to the bottom of the servo rotating assembly, and includes a chassis, the bottom surface of which is provided with an arc-shaped polishing member and a nozzle;

[0009] The gas-liquid joint is connected to the nozzle through the gas-liquid path inside the processing component.

[0010] In one embodiment, the arc-shaped polishing member covers a portion of the edge of the wafer.

[0011] In one embodiment, during the edge processing process, the base plate is tilted relative to the wafer, and the base plate is closer to the edge of the wafer than the center of the wafer.

[0012] In one embodiment, the tilt angle between the base plate and the wafer during grinding and polishing is 0.1 to 5 degrees.

[0013] In one embodiment, a plurality of arc-shaped polishing members are evenly spaced and arranged on the bottom surface of the chassis near the edge.

[0014] In one embodiment, a plurality of nozzles are provided along the radial direction of the chassis.

[0015] In one embodiment, the nozzles located on the outside are arranged to spray at an angle, with the angled direction being towards the edge.

[0016] In one embodiment, the arc-shaped polishing member includes an arc-shaped oilstone and an arc-shaped brush.

[0017] In one embodiment, the arc-shaped polishing member includes a arc-shaped polishing pad and an arc-shaped brush.

[0018] In one embodiment, the bottom surface of the arc-shaped polishing pad is provided with grid-shaped grooves or tangential grooves.

[0019] In one embodiment, the curved polishing member covers the entire edge of the wafer.

[0020] The beneficial effects of the embodiments of the present invention include: using the processing assembly to polish the edge of the wafer can grind off the tip of the edge, making the edge of the wafer smoother and reducing the possibility of debris being easily generated on the edge during the polishing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The advantages of the present invention will become clearer and easier to understand through the detailed description made in conjunction with the following drawings, but these drawings are only exemplary and do not limit the scope of protection of the present invention, among which:

[0022] Figure 1 FIG2 shows a wafer thinning device provided by an embodiment of the present invention;

[0023] Figure 2 A wafer edge processing device provided by an embodiment of the present invention is shown;

[0024] Figure 3 The processing components provided in Example 1 are shown;

[0025] Figure 4 The processing components provided in Example 2 are shown;

[0026] Figure 5 The processing components provided in Example 3 are shown;

[0027] Figure 6 FIG2 shows a wafer edge processing device provided by another embodiment of the present invention;

[0028] Figure 7 The processing components provided by Example 4 are shown. DETAILED DESCRIPTION

[0029] The technical solutions of the present invention are described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments described herein are specific embodiments of the present invention and are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be understood as limiting the embodiments of the present invention and the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications to the embodiments described herein. It should be understood that, unless otherwise specified, for ease of understanding, the following descriptions of the specific embodiments of the present invention are all based on the description of the relevant equipment, devices, components, etc. in their original static natural state without external control signals and driving forces.

[0030] In addition, it should be noted that the terms used in this application to indicate directions, such as front, back, up, down, left, right, top, bottom, front, back, horizontal, vertical, etc., are only for the convenience of description to help understand the relative position or direction, and are not intended to limit the orientation of any device or structure.

[0031] In order to illustrate the technical solution of the present invention, the following description will be made with reference to the accompanying drawings and in combination with embodiments.

[0032] In this application, chemical mechanical polishing is also referred to as chemical mechanical planarization, and wafer is also referred to as chip, silicon chip, base plate or substrate, etc., and their meanings and actual functions are equivalent.

[0033] The wafer thinning equipment provided in the embodiments of the present disclosure is mainly used for thinning the back side of the wafer. The back side here refers to the side of the wafer without devices, which is generally the substrate. The substrate material can be silicon, silicon oxide, silicon nitride, silicon carbide, sapphire, etc.

[0034] Figure 1 The wafer thinning device provided by one embodiment of the present invention includes:

[0035] The front-end module 1 is used to facilitate wafer loading and unloading. It is located at the front end of the wafer thinning equipment. It is a transition module that transfers wafers from the outside to the inside of the equipment, enabling wafer loading and unloading, thus achieving "dry-in, dry-out" of wafers.

[0036] A grinding module 3 is used for grinding the wafer, wherein the grinding includes rough grinding and fine grinding. The grinding module 3 is arranged at the end of the wafer thinning equipment;

[0037] The polishing module 2 is used to perform chemical mechanical polishing on the wafer after completing the grinding, and also has the function of transferring the wafer between these three modules (equipment front-end module 1, grinding module 3 and polishing module 2). The polishing module 2 is arranged between the equipment front-end module 1 and the grinding module 3.

[0038] It is understandable that the polishing module 2 is not a necessary technical feature and is dispensable. In another embodiment, the wafer thinning equipment only includes the equipment front-end module 1 and the grinding module 3 and the transmission mechanism therebetween, and does not have the chemical mechanical polishing function, which should also fall within the scope of protection of this application.

[0039] Device front-end module 1:

[0040] The front-end module 1 of the equipment includes a wafer storage unit 11 and a first transfer unit 12. The wafer storage unit 11 is set on the front side of the wafer thinning equipment, and the first transfer unit 12 is set between the wafer storage unit 11 and the polishing module 2 to realize the transfer of wafers between the wafer storage unit 11 and the polishing module 2.

[0041] The wafer storage unit 11 is composed of multiple front-opening unified pods (FOUPs), specifically two or three. A front-opening unified pod is a container used in semiconductor manufacturing to protect, transport, and store wafers. Its main components are a front-opening container that holds the wafers and a front-opening door structure that is airtightly connected to the outer wall of the wafer thinning equipment, connecting the front-opening container to the interior of the equipment.

[0042] The first transport unit 12 includes a wafer handling robot. This robot can rotate, extend, fold, and retract, and can also move along the transport track. The robot is a dryer robot, used to handle dry and clean wafers. The robot can retrieve unprocessed wafers from the wafer storage unit 11 through the door structure of the wafer pod and transfer them to the polishing module 2. It can also receive processed wafers from the polishing module 2 and place them into the wafer pod.

[0043] Polishing Module 2:

[0044] The polishing module 2 includes a second transfer unit 21, a third transfer unit 22, a chemical mechanical polishing unit 23 and a post-processing unit 24. The second transfer unit 21, the chemical mechanical polishing unit 23 and the post-processing unit 24 occupy the edges of the polishing module 2 respectively, and the third transfer unit 22 is located in the center.

[0045] Specifically, the second transfer unit 21 is located on one edge of the polishing module 2 and extends along the length of the device, connecting the front-end module 1 and the grinding module 3. The chemical mechanical polishing unit 23 is located on the other edge of the polishing module 2, adjacent to the grinding module 3 and the second transfer unit 21. The post-processing unit 24 is located on another edge of the polishing module 2, adjacent to the front-end module 1, the second transfer unit 21, and the chemical mechanical polishing unit 23. The third transfer unit 22 is located near the center of the polishing module 2, surrounded by the second transfer unit 21, the chemical mechanical polishing unit 23, and the post-processing unit 24. It is used to transfer wafers between the second transfer unit 21, the chemical mechanical polishing unit 23, and the post-processing unit 24.

[0046] In one embodiment, the second transport unit 21 includes a temporary storage unit and a mobile buffer unit for temporarily storing and transporting wafers. The temporary storage unit is located adjacent to the front-end module 1 of the equipment and is used to temporarily store or transfer wafers. The mobile buffer unit is located along the direction from the front-end module 1 to the grinding module 3 and is movable in both directions.

[0047] In one embodiment, the third transfer unit 22 includes a central robot, which is used to transfer the ground wafers from the mobile cache unit to the chemical mechanical polishing unit 23, transfer the polished wafers from the chemical mechanical polishing unit 23 to the post-processing unit 24, and transfer the cleaned wafers from the post-processing unit 24 to the temporary storage unit.

[0048] After the wafer is taken out from the equipment front-end module 1, it is transported to the grinding module 3 via the second transfer unit 21 for grinding; after the wafer is ground in the grinding module 3, it is transported to the chemical mechanical polishing unit 23 via the second transfer unit 21 and the third transfer unit 22 for polishing; after polishing and cleaning, the wafer is transferred back to the equipment front-end module 1 via the third transfer unit 22 and the second transfer unit 21.

[0049] The post-processing unit 24 is used to clean and dry the polished wafer, and may include a horizontal scrubbing device and a single-chamber cleaning device.

[0050] Grinding Module 3:

[0051] The grinding module 3 includes a grinding unit 31 , a cleaning unit 32 and a fourth transport unit 33 .

[0052] The grinding unit 31 is used for wafer grinding and thickness measurement. It includes a worktable, suction cups mounted on the worktable, and grinding wheels corresponding to the suction cups. Three suction cups are provided, which can rotate between rough grinding, fine grinding, and loading and unloading stations. Two grinding wheels perform rough grinding and fine grinding, respectively.

[0053] The fourth transfer unit 33 includes a simple robot, which takes the wafer from the second transfer unit 21 and sends it to the grinding unit 31 for grinding. After grinding and cleaning, the simple robot takes the wafer from the grinding unit 31 and places it in the second transfer unit 21 for subsequent transmission of the wafer.

[0054] like Figure 1 As shown, the cleaning unit 32 is used to implement chuck cleaning, polishing and wafer processing.

[0055] The cleaning unit 32 includes a suction cup processing device and a wafer edge processing device 40, both of which are mounted on a support frame 34. The support frame 34 is located on one side of the workbench, and the grinding wheel is located on the other side of the workbench. The support frame 34 is adjacent to the loading and unloading station to process the suction cups and / or wafers moved to the loading and unloading station. The suction cup processing device and the wafer edge processing device 40 are respectively connected to the support frame 34 via a horizontal movement mechanism. The horizontal movement mechanism can drive the suction cup processing device and the wafer edge processing device 40 to move horizontally to change the position of the suction cup processing device and the wafer edge processing device 40 relative to the suction cup. When the suction cup processing device or the wafer edge processing device 40 is moved directly above the suction cup, the suction cup or wafer can be processed. When the suction cup processing device and the wafer edge processing device 40 are moved away from the suction cup, a simple robot can be used to remove the wafer from the suction cup.

[0056] Figures 2 to 7 A wafer edge processing device 40 provided in the present application is shown.

[0057] like Figure 2 As shown, the wafer edge processing device 40 includes:

[0058] A lifting assembly 50 connected to a support frame 34 in the wafer thinning equipment;

[0059] The servo rotation assembly 60 is connected to the lifting assembly 50;

[0060] The processing assembly 70 is connected to the bottom of the servo rotating assembly 60 and includes a base plate 71. The bottom surface of the base plate 71 is provided with an arc-shaped polishing member 72 and a nozzle 73;

[0061] The gas-liquid joint 80 is connected to the nozzle 73 through the gas-liquid path inside the processing assembly 70 .

[0062] In this embodiment, the lifting assembly 50 is capable of driving the servo rotary assembly 60 and the processing assembly 70 at its bottom to move vertically up and down, thereby adjusting the distance between the base 71 of the processing assembly 70 and the wafer W. When the horizontal movement mechanism moves the wafer edge processing device 40 to directly above the wafer W at the loading and unloading station, the lifting assembly 50 drives the processing assembly 70 to move into contact with the wafer W, and the servo rotary assembly 60 drives the processing assembly 70 to rotate, thereby using the arc-shaped polishing member 72 to polish the edge of the wafer W, removing the sharp tip and making the edge of the wafer W smoother, thereby reducing the possibility of debris generated at the edge during the polishing process.

[0063] In one embodiment, the servo rotating assembly 60 includes a rotating motor, a speed reducer, a coupling, and a rotating shaft connected in sequence, and the rotating shaft is connected to the chassis 71 of the processing assembly 70 .

[0064] In one embodiment, the gas-liquid connector 80 is connected to an external deionized water source, so that the deionized water enters the nozzle 73 through the gas-liquid path within the processing assembly 70, and is then sprayed by the nozzle 73 onto the surface of the wafer w for cleaning. It is understood that in order to improve the scattering effect of the fluid, some gas, such as air, can be added to the deionized water source to ensure the cleaning effect of the fluid sprayed by the nozzle 73.

[0065] Since the wafer w will have edge chipping (broken edges) after grinding, and the subsequent polishing process will also have edge chipping, which may cause scratches on the wafer w, using the processing component 70 to grind the edge of the wafer w can complete the subsequent edge chipping phenomenon in advance in this process, reducing the probability of edge chipping in the subsequent polishing process, thereby reducing the probability of wafer w being damaged.

[0066] The processing component 70 in the embodiment of the present invention can be implemented in a variety of ways, which are described in detail below.

[0067] Example 1

[0068] like Figure 2 and Figure 3 As shown, the bottom surface of the chassis 71 of the processing assembly 70 in Example 1 is provided with an arc-shaped polishing member 72 and a nozzle 73. The bottom surface of the chassis 71 is circular, and the arc-shaped polishing member 72 is an arc concentric with the chassis 71 and is used to polish the edge of the wafer.

[0069] like Figure 2 As shown, the diameter of the chassis 71 is slightly larger than the radius of the wafer W. Specifically, the outer diameter of the arc-shaped polishing member 72 is 10 to 30 mm longer than the radius of the wafer W. Preferably, when the processed wafer W is a 12-inch wafer, the outer diameter of the arc-shaped polishing member 72 is 170 mm, that is, 20 mm longer than the radius of the wafer.

[0070] like Figure 2As shown, in this embodiment, the diameter of the chassis 71 is slightly larger than the radius of the wafer w. In other words, the arc-shaped polishing member 72 and the wafer w are processed in a semi-contact manner. Since the edge of the wafer w is mainly polished, the protruding tip of the edge of the wafer w needs to be polished smooth. Therefore, during the edge processing process, the chassis 71 is relatively tilted with respect to the wafer w, and the chassis 71 is closer to the edge of the wafer w than the center of the wafer w. In this way, the downward pressure on the edge is greater, and the polishing effect is better and faster. Specifically, during polishing, the tilt angle between the chassis 71 and the wafer w is 0.1 to 5 degrees, preferably 1 to 3 degrees.

[0071] like Figure 3 As shown, multiple nozzles 73 are provided along the radius of the chassis 71 and arranged in a linear array. As a variation of this embodiment, the nozzles 73 can also be arranged in a curved pattern radiating outward from the center of the chassis 71, that is, a group of nozzles 73 can be distributed along a curve on the chassis 71. The nozzles 73 spray liquid onto the surface of the wafer w to wash away particles generated by grinding and polishing. Furthermore, the nozzles 73 located on the outside are configured to spray liquid at an angle, with the tilt direction toward the edge.

[0072] like Figure 3 As shown, multiple arcuate polishing members 72 are evenly spaced and arranged on the bottom surface of the chassis 71 near the edge. The arcuate polishing members 72 include arcuate oilstones 74 and arcuate brushes 75. The arcuate oilstones 74 and arcuate brushes 75 are evenly arranged on the edge of the chassis 71. The width of the arcuate oilstones 74 is 4 to 6 mm, the thickness of the arcuate oilstones 74 is 5 to 10 mm, and the grit of the arcuate oilstones 74 is 200 to 600. The arcuate brushes 75 are made of hard bristles and have the same width and thickness as the arcuate oilstones 74.

[0073] Example 2

[0074] like Figure 2 and Figure 4 As shown, in Example 2, the diameter of the chassis 71 is slightly larger than the radius of the wafer w. During the edge processing process, the chassis 71 and the wafer w are relatively tilted, and the chassis 71 is closer to the edge of the wafer w than the center of the wafer w.

[0075] like Figure 4 As shown, the arc-shaped polishing member 72 includes an arc-shaped polishing pad 76 and an arc-shaped brush 75. The arc-shaped polishing pad 76 and the arc-shaped brush 75 are evenly arranged on the edge of the chassis 71. The arc-shaped polishing pad 76 can be made of polyurethane. In Example 2, the bottom surface of the arc-shaped polishing pad 76 is provided with a grid-shaped groove for abutting and polishing the wafer w. The width of the arc-shaped polishing pad 76 is 4 to 10 mm, preferably 6 mm. The thickness of the arc-shaped polishing pad 76 is 2 to 6 mm, preferably 3 mm. The width of the arc-shaped brush 75 is the same as that of the arc-shaped polishing pad 76, and the thickness of the arc-shaped brush 75 is 5 to 10 mm.

[0076] Example 3

[0077] like Figure 2 and Figure 5 As shown, in Example 3, the diameter of the chassis 71 is slightly larger than the radius of the wafer w. During the edge processing process, the chassis 71 and the wafer w are relatively tilted, and the chassis 71 is closer to the edge of the wafer w than the center of the wafer w.

[0078] like Figure 5 As shown, the curved polishing member 72 includes a curved polishing pad 76 and a curved brush 75. The curved polishing pad 76 and the curved brush 75 are evenly arranged along the edge of the base 71. In Example 3, the bottom surface of the curved polishing pad 76 is provided with a tangential groove. The tangential groove forms an angle with the curved edge of the curved polishing pad 76; in other words, the tangential groove is not parallel to the curved edge. Preferably, the tangential groove extends perpendicular to the rotation direction of the curved polishing pad 76, thereby effectively polishing the edge of the wafer w.

[0079] Example 4

[0080] like Figure 6 and Figure 7 As shown, in Example 4, the diameter of the base 71 is slightly larger than the diameter of the wafer w, so that the curved polishing member 72 covers the entire edge of the wafer w. Specifically, the outer diameter of the curved polishing member 72 is 1-5 mm longer than the diameter of the wafer w. Preferably, when the processed wafer w is a 12-inch wafer, the outer diameter of the curved polishing member 72 is 302 mm, which is 2 mm longer than the diameter of the wafer w. Furthermore, the curved polishing member 72 can also be a complete ring.

[0081] like Figure 7 As shown, the arcuate polishing member 72 includes an arcuate oilstone 74 and an arcuate brush 75. The arcuate oilstone 74 and the arcuate brush 75 are evenly arranged on the edge of the base 71. The width of the arcuate oilstone 74 is 4 to 6 mm, the thickness of the arcuate oilstone 74 is 5 to 10 mm, and the grit of the arcuate oilstone 74 is 200 to 600. The arcuate brush 75 is made of hard bristles and has the same width and thickness as the arcuate oilstone 74.

[0082] Alternatively, the curved polishing member 72 includes a curved polishing pad 76 and a curved brush 75. The curved polishing pad 76 and the curved brush 75 are evenly arranged on the edge of the base 71. The bottom surface of the curved polishing pad 76 is provided with a grid-like groove or a tangential groove. The width of the curved polishing pad 76 is 4 to 10 mm, preferably 6 mm. The thickness of the curved polishing pad 76 is 2 to 6 mm, preferably 3 mm. The width of the curved brush 75 is the same as that of the curved polishing pad 76, and the thickness of the curved brush 75 is 5 to 10 mm.

[0083] The drawings in this specification are schematic diagrams that assist in illustrating the concepts of the present invention and schematically illustrate the shapes of the various components and their interrelationships. It should be understood that in order to clearly illustrate the structures of the various components of the embodiments of the present invention, the drawings are not drawn to the same scale, and the same reference numerals are used to represent the same parts in the drawings.

[0084] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0085] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A wafer edge processing device, characterized in that: include: A lifting assembly connected to a support frame in the wafer thinning equipment; a servo rotating assembly connected to the lifting assembly; A processing assembly is connected to the bottom of the servo rotation assembly and includes a chassis. The bottom surface of the chassis is provided with an arc-shaped polishing member and a nozzle. The lifting assembly drives the processing assembly to move to abut the wafer, and the servo rotation assembly drives the processing assembly to rotate, thereby using the arc-shaped polishing member to polish the edge of the wafer; A plurality of arc-shaped polishing members are evenly spaced and arranged on the bottom surface of the chassis near the edge, the arc-shaped polishing members covering part of the edge of the wafer, and the arc-shaped polishing members include an arc-shaped oilstone and an arc-shaped brush, or an arc-shaped polishing pad and an arc-shaped brush; An air-liquid joint is connected to a nozzle through an air-liquid path inside the processing assembly. The nozzle sprays liquid onto the surface of the wafer for cleaning. Multiple nozzles are arranged along the radial direction of the chassis. The nozzles located on the outer side are arranged to spray at an angle, with the tilt direction facing the edge. During the edge processing process, the chassis and the wafer are tilted relative to each other, and the chassis is closer to the edge of the wafer than the center of the wafer. The arc-shaped polishing part and the wafer are processed in a semi-contact manner.

2. The wafer edge processing device according to claim 1, wherein: During grinding and polishing, the tilt angle between the base plate and the wafer is 0.1 to 5 degrees.

3. The wafer edge processing device according to claim 2, wherein: The outer diameter of the arc-shaped polishing member is 10 to 30 mm longer than the radius of the wafer.

4. The wafer edge processing device according to claim 1, wherein: The bottom surface of the arc-shaped polishing pad is provided with grid-shaped grooves or tangential grooves.

Images