An apparatus and method for oriented processing of gallium oxide wafers
By combining the design of angle adjustment fixtures and grinding equipment, the high-precision problem of gallium oxide wafer crystal surface angle repair was solved, achieving precision control within 0.1° and ensuring high-quality processing of gallium oxide wafers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HANGZHOU GAREN SEMICON CO LTD
- Filing Date
- 2024-12-06
- Publication Date
- 2026-06-09
AI Technical Summary
Existing technologies struggle to achieve high-precision repair of the crystal plane angles of large-size gallium oxide wafers, especially after cutting, where it is difficult to effectively control the precision to within 0.1°.
A device including an angle adjustment fixture and a processing fixture was designed. The wafer is bonded to the bottom of the angle adjustment fixture and its angle is adjusted. Grinding is carried out in conjunction with a grinding equipment. Orientation and quantitative repair are performed using a grinding disc. The crystal surface angle is detected and adjusted in real time.
It achieves high-precision repair of the crystal plane angle of gallium oxide wafers after cutting, controlling the error range within 0.1°, ensuring processing quality and accuracy.
Smart Images
Figure CN122165272A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of wafer processing technology, and in particular to an apparatus and method for directional processing of gallium oxide wafers. Background Technology
[0002] Gallium oxide (GaO) is a semiconductor material exhibiting anisotropy, a characteristic that presents challenges for GaO processing, particularly in wafer dicing and crystal surface finishing. Traditional processing methods involve directional dicing of the crystal ingot during the dicing process, evaluating the overall lattice angle based on the angle of the ingot's end face. However, due to internal crystal stress and dicing warpage, the crystal surface angle accuracy for large-size GaO wafers can only be controlled within 1°, making subsequent correction of the wafer's crystal surface angle impossible. Therefore, there is an urgent need to design a technical solution capable of correcting the crystal surface angle of diced wafers. Summary of the Invention
[0003] The purpose of this invention is to provide an apparatus and method for directional processing of gallium oxide wafers, in order to solve the problems existing in the prior art and to repair the crystal plane angles of the cut wafers.
[0004] To achieve the above objectives, the present invention provides the following solution:
[0005] This invention provides an apparatus for directional processing of gallium oxide wafers, comprising:
[0006] An angle adjustment fixture, the bottom of which is used to bond the wafer and can adjust the angle of the wafer;
[0007] The processing fixture is fixedly connected to the top of the angle adjustment fixture and places the wafer above the grinding equipment, where it elastically contacts the grinding disc for grinding. The grinding equipment is a traditional device that uses a motor to drive the grinding disc to rotate. This invention is placed above the grinding disc, and movable guide wheels are located on the outer periphery of the grinding disc to fix the invention in place. The grinding equipment is a traditional processing method, so it will not be described in detail.
[0008] Preferably, the angle adjustment fixture includes a reference part and an adhesive part, the adhesive part is connected to the reference part, and the angle of the adhesive part can be adjusted relative to the adhesive part; the bottom of the adhesive part is fixedly bonded to the wafer, and the reference part is fixedly connected to the processing fixture.
[0009] Preferably, the reference part is a horizontally arranged reference plate, and the adhesive part is a ceramic block; a plurality of elastic screws are arranged around the end face of the reference plate near the side, and the ends of the elastic screws are threadedly connected to the ceramic block.
[0010] Preferably, the processing fixture includes an internally hollow annular seat, a flat support plate connected to the top of the annular seat, an adsorption component passing through the center of the flat support plate, and the bottom of the adsorption component being used to fix and adsorb the upper surface of the angle adjustment fixture.
[0011] Preferably, the adsorption assembly includes a hollow connecting shaft, a vacuum suction cup fixedly connected to the bottom of the connecting shaft, and a vacuum pump externally connected to the top of the connecting shaft. The vacuum suction cup is used to adsorb the upper surface of the angle adjustment fixture; the connecting shaft passes through the planar support plate.
[0012] Preferably, a limiting ring is fixedly sleeved on the upper part of the connecting shaft, and a limiting part is provided on the planar support plate. The connecting shaft passes through the central hole of the limiting part and the central hole of the planar support plate in sequence, and there is no contact between the outer wall of the connecting shaft and the inner wall of the central hole of the limiting part and the inner wall of the central hole of the planar support plate; the bottom of the limiting ring is fixedly abutted against the limiting part by an elastic element.
[0013] Preferably, the limiting part includes a connecting ring fixed to the planar support plate, and a pressure knob is threadedly connected to the outer wall of the connecting ring, with the bottom of the elastic element abutting against the pressure knob.
[0014] Preferably, the annular seat is provided with a plurality of threaded sleeves, and the threaded sleeves are internally threaded with vertically arranged horizontal adjusting screws, the top of which is connected to the planar support plate.
[0015] Preferably, the bottom of the annular seat is provided with an outer protective ring of an annular structure, and the bottom of the outer protective ring is provided with a plurality of horizontally arranged arc-shaped grooves pointing to the center of the outer protective ring.
[0016] The present invention also provides a method for directional processing of gallium oxide wafers, comprising the following steps:
[0017] Step 1: The wafer is bonded to the bottom of the bonding part of the angle adjustment fixture using paraffin wax, and the wafer angle is detected using an orientation device;
[0018] Step 2: By using the orientation equipment to provide feedback on the crystal plane angle value, adjust the bonding part to adjust the crystal plane angle of the wafer to the target angle requirement;
[0019] Step 3: Use diamond grinding powder and mix it with water at a weight ratio of 1:10 to 1:20 to prepare a grinding slurry. Adsorb the adjusted angle adjustment fixture onto the processing fixture and place it on the grinding equipment so that the wafer comes into contact with the grinding disc for thinning grinding.
[0020] Step 4: During the grinding process, measure the angle of the grinding crystal surface and make real-time adjustments based on the changes in the crystal surface angle;
[0021] Step 5: Once the entire crystal surface has been ground to the target angle, the processing is complete, and the wafer is removed.
[0022] The present invention achieves the following technical effects compared to the prior art:
[0023] This invention fixes the cut wafer to the bottom of an angle adjustment fixture, adjusts the wafer angle according to the location and amount to be repaired, and then contacts it with a grinding disc to achieve directional and quantitative repair of the wafer angle through grinding. It can detect changes in crystal surface angle in real time and adjust the processing direction in real time, thereby producing wafers that meet the requirements. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 This is a schematic diagram of an apparatus for directional processing of gallium oxide wafers according to one embodiment of the present invention;
[0026] Figure 2 This is a schematic cross-sectional view of an apparatus for directional processing of gallium oxide wafers according to one embodiment of the present invention;
[0027] Figure 3 This is a schematic diagram of the connecting shaft and vacuum suction cup according to one embodiment of the present invention;
[0028] Figure 4 This is a schematic diagram of an angle adjustment fixture according to one embodiment of the present invention;
[0029] Figure 5 This is a schematic diagram illustrating the adjustment method of the angle adjustment fixture in one embodiment of the present invention.
[0030] In the diagram: 1-Connecting shaft, 2-Limiting ring, 3-Pressure spring, 4-Pressure knob, 5-Connecting ring, 6-Flat support plate, 7-Horizontal adjustment screw, 8-Vacuum suction cup, 9-Angle adjustment fixture, 901-Base plate, 902-Ceramic block, 10-Outer protective ring, 1001-Arc groove. Detailed Implementation
[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0032] The purpose of this invention is to provide an apparatus and method for directional processing of gallium oxide wafers, in order to solve the problems existing in the prior art and to repair the crystal plane angles of the cut wafers.
[0033] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0034] Gallium oxide (GaO) is an anisotropic material, meaning its physical properties differ in different directions. This characteristic presents challenges for GaO processing, particularly in wafer dicing and crystal surface finishing. The inventors' known processing method involves determining the crystal face angles of the wafer during the ingot-to-wafer cutting process. However, due to internal crystal stress and cutting warpage, the accuracy of the crystal face angles for large-size GaO wafers can only be controlled within 1°. The anisotropic and easily cleaved nature of GaO means that traditional grinding wheels cannot be used for directional thinning of GaO wafers. During processing, the excessive mechanical force of traditional grinding wheels leads to wafer breakage or edge cleavage. To achieve angle repair of the cut wafers, this invention designs a device for directional processing of GaO wafers, referencing… Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, it includes an angle adjustment fixture 9 and a processing fixture. The bottom of the angle adjustment fixture 9 is used to bond the wafer and can adjust the angle of the wafer, enabling 0 to 2° directional processing at different positions of the wafer. The processing fixture can be fixedly connected to the top of the angle adjustment fixture 9 and place the wafer above the grinding equipment, so that it can be elastically contacted with the grinding disc of the grinding equipment for grinding.
[0035] To enable processing at different angles at different positions on the wafer, the reference part of the angle adjustment fixture 9 in this embodiment adopts a horizontally arranged reference plate 901, and the bonding part adopts a ceramic block 902. Multiple elastic screws are arranged around the end face of the reference plate 901 near the side. The ends of the elastic screws are threadedly connected to the ceramic block 902. By adjusting the connection length of the elastic screws at different positions, the ceramic block 902 can be deflected in different directions and at different angles relative to the reference plate 901. The wafer is fixedly bonded to the bottom of the ceramic block 902, thereby enabling the adjustment of the wafer's angle and position. This facilitates cooperation with the grinding disc below to achieve grinding of different processing amounts at different positions on the wafer.
[0036] In one specific embodiment, the processing fixture includes a hollow annular seat, with a flat support plate 6 connected to the top of the annular seat. The flatness of the upper and lower surfaces of the flat support plate 6 is <0.02mm, mainly to ensure the verticality of the applied pressure and to ensure the overall thickness difference of the processed product. A connecting ring 5 is fixedly provided at the center of the flat support plate 6, and a pressure knob 4 is threadedly connected to the outer wall of the connecting ring 5. The hollow connecting shaft 1 of the adsorption assembly passes through the pressure knob 4, the connecting ring 5 and the flat support plate 6 in sequence and is then fixedly connected to a vacuum suction cup 8. A vacuum pump is externally connected to the top of the connecting shaft 1. The vacuum suction cup 8 is used to adsorb the upper surface of the reference plate 901 of the angle adjustment fixture 9. In a preferred embodiment, the vacuum suction cup 8 and the connecting shaft 1 are integrally machined. With the bottom of the vacuum suction cup 8 as the reference, the verticality of the connecting shaft 1 is ensured to be <0.2° during processing. An annular connecting groove is cut out at the bottom of the vacuum suction cup 8 by a milling cutter, and the center of the connecting shaft 1 is completely penetrated. Under the action of negative pressure adsorption, the angle adjustment fixture 9 is adsorbed.
[0037] In this embodiment, a limiting ring 2 is fixedly sleeved on the upper part of the connecting shaft 1. The bottom of the limiting ring 2 is fixedly abutted against the pressure knob 4 by an elastic element, which is a pressure spring 3. By adjusting the position of the pressure knob 4 on the connecting ring 5, the compression force of the pressure spring 3 can be adjusted. The forward processing pressure can be controlled by adjusting the reverse support force of the pressure spring 3. Furthermore, the elastic support of the pressure spring 3 can eliminate the self-weight pressure of the connecting shaft 1, thereby achieving light pressure control processing and ensuring the quality of wafer processing. Further, the limiting ring 2 is fixed to the connecting shaft 1 by a side screw. The processing pressure adjustment range can be controlled by adjusting the position of the limiting ring 2 on the connecting shaft 1. The force can be adjusted within the range of 50-10000g, with an adjustment accuracy of 10g. The weight of the connecting shaft 1, vacuum chuck 8, and the adjustment fixture as a whole is 10kg, so the maximum processing pressure can reach 10kg. Through the counter-pressure support of the pressure spring 3, the bottom wafer can be controlled to contact the grinding disc with zero pressure. The compression of the pressure spring 3 can be adjusted by the pressure knob 4 to control the processing pressure. At the same time, in the overall structure, the gaps at the component connections are all finely adjusted. The distance between the inner wall of the center hole of the connecting shaft 1 and the connecting ring 5 is 0.1-0.3mm, which makes up for the product processing accuracy deviation caused by the component processing or assembly tolerance, thereby achieving high-precision machining.
[0038] To adjust the flatness of the planar support plate 6, this embodiment includes multiple threaded sleeves annularly mounted on the ring seat. Vertically arranged horizontal adjusting screws 7 are threaded into the inner threads of each sleeve. The tops of the horizontal adjusting screws 7 are connected to the planar support plate 6. In one specific embodiment, the four horizontal adjusting screws 7 precisely adjust the levelness of the planar support plate 6 in four directions. The four horizontal adjusting screws 7 are arranged symmetrically in sequence, with two diagonally arranged screws forming a group. One group consists of set screws used to support the planar support plate 6, and the other group consists of tightening screws used to fix the planar support plate 6 after its position has been adjusted. During adjustment, a level is placed on the planar support plate 6, and the height of the horizontal adjusting screws 7 is adjusted while the level changes are monitored in real time to achieve the required flatness of the planar support plate 6.
[0039] In this embodiment, an outer protective ring 10 with an annular structure is provided at the bottom of the annular seat. The outer protective ring 10 is made of high-strength and wear-resistant tungsten steel material and is used to support the entire device. Multiple horizontally arranged arc-shaped grooves 1001 pointing to the center of the outer protective ring 10 are provided at the bottom of the outer protective ring 10. During the grinding process, the arc-shaped grooves 1001 form multiple channels arranged in a circumferential array for the dispersion of grinding fluid.
[0040] Based on the above solution, the present invention also provides a method for directional processing of gallium oxide wafers, comprising the following steps:
[0041] Step 1: The wafer is bonded to the bottom of the bonding part of the angle adjustment fixture 9 using paraffin wax, and the wafer angle is detected by the orientation device;
[0042] Step 2, refer to Figure 5 As shown, the crystal plane angle value is fed back by the orientation device, and the bonding part is adjusted to adjust the crystal plane angle of the wafer to the target angle requirement; the orientation device has a known structure, which includes a radiation emitter and a receiver, such as... Figure 5 As shown, when X-rays are shone into a wafer, different angles of diffraction are generated on different crystal surfaces. Then, based on the diffracted rays received by the receiver, the angular deviation of the wafer's crystal surface is calculated from the diffraction angle. This is a mature solution and will not be elaborated further.
[0043] Step 3: Use diamond grinding powder and mix it with water at a weight ratio of 1:10 to 1:20 to prepare a grinding slurry. Adsorb the adjusted angle adjustment fixture 9 onto the processing fixture and place it on the grinding equipment so that the wafer comes into contact with the grinding disc for thinning grinding.
[0044] Step four: During the grinding process, the angle of the grinding crystal surface is measured and adjusted in real time according to the change of the crystal surface angle; after each grinding, the wafer can be quickly removed, the angle deviation of the wafer after grinding is measured, and the angle is adjusted in time. After multiple grinding adjustments, a gallium oxide wafer with a high-precision crystal surface is prepared.
[0045] Step 5: Once the entire crystal surface has been ground to the target angle, the processing is complete, and the wafer is removed. The grinding amount and the deviation of the crystal surface angle during processing are shown in Table 1. Grinding 1, Grinding 2, and Grinding 3 in Table 1 refer to different stages of grinding the same wafer. For example, Grinding 1 corresponds to grinding the entire wafer to 10µm, Grinding 2 corresponds to grinding the entire wafer to 15µm, and Grinding 3 corresponds to grinding the entire wafer to 21µm.
[0046] Table 1
[0047] Processing steps initial state After patch Grinding 1 Grinding 2 Grinding 3 After filming Grinding amount (µm) 0 5 10 15 21 21 Crystal plane angle deviation (°) 1.25 1.23 0.81 0.46 0.05 0.07
[0048] By using the above methods, the crystal plane angle after grinding can be controlled within an error range of 0.1°.
[0049] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.
Claims
1. An apparatus for directional processing of gallium oxide wafers, characterized in that: include: An angle adjustment fixture, the bottom of which is used to bond the wafer and can adjust the angle of the wafer; The processing fixture is able to be fixedly connected to the top of the angle adjustment fixture and place the wafer above the grinding equipment, so that it can be elastically ground in contact with the grinding disc of the grinding equipment.
2. The apparatus for directional processing of gallium oxide wafers according to claim 1, characterized in that: The angle adjustment fixture includes a reference part and an adhesive part. The adhesive part is connected to the reference part, and the angle of the adhesive part can be adjusted relative to the adhesive part. The wafer is fixedly bonded to the bottom of the adhesive part, and the reference part is fixedly connected to the processing fixture.
3. The apparatus for directional processing of gallium oxide wafers according to claim 2, characterized in that: The reference part is a horizontally arranged reference plate, and the adhesive part is a ceramic block; multiple elastic screws are arranged around the end face of the reference plate near the side, and the ends of the elastic screws are threadedly connected to the ceramic block.
4. The apparatus for directional processing of gallium oxide wafers according to claim 1, characterized in that: The processing fixture includes a hollow annular seat, a flat support plate connected to the top of the annular seat, an adsorption component inserted at the center of the flat support plate, and the bottom of the adsorption component used to fix and adsorb the upper surface of the angle adjustment fixture.
5. The apparatus for directional processing of gallium oxide wafers according to claim 4, characterized in that: The adsorption assembly includes a hollow connecting shaft, a vacuum suction cup fixedly connected to the bottom of the connecting shaft, and a vacuum pump externally connected to the top of the connecting shaft. The vacuum suction cup is used to adsorb the upper surface of the angle adjustment fixture. The connecting shaft passes through the planar support plate.
6. The apparatus for directional processing of gallium oxide wafers according to claim 5, characterized in that: A limiting ring is fixedly sleeved on the upper part of the connecting shaft, and a limiting part is provided on the planar support plate. The connecting shaft passes through the center hole of the limiting part and the center hole of the planar support plate in sequence, and there is no contact between the outer wall of the connecting shaft and the inner wall of the center hole of the limiting part and the inner wall of the center hole of the planar support plate; the bottom of the limiting ring is fixedly abutted against the limiting part by an elastic element.
7. The apparatus for directional processing of gallium oxide wafers according to claim 6, characterized in that: The limiting part includes a connecting ring fixed to the planar support plate, and a pressure knob is threadedly connected to the outer wall of the connecting ring. The bottom of the elastic element abuts against the pressure knob.
8. The apparatus for directional processing of gallium oxide wafers according to claim 4, characterized in that: The annular seat is surrounded by multiple threaded sleeves, and each threaded sleeve is internally threaded with a vertically arranged horizontal adjusting screw. The top of the horizontal adjusting screw is connected to the planar support plate.
9. The apparatus for directional processing of gallium oxide wafers according to claim 4, characterized in that: The bottom of the annular seat is provided with an outer protective ring of an annular structure, and the bottom of the outer protective ring is provided with multiple horizontally arranged arc-shaped grooves pointing to the center of the outer protective ring.
10. A method for directional processing of gallium oxide wafers, characterized in that: Includes the following steps: Step 1: The wafer is bonded to the bottom of the bonding part of the angle adjustment fixture using paraffin wax, and the wafer angle is detected using an orientation device; Step 2: By using the orientation equipment to provide feedback on the crystal plane angle value, adjust the bonding part to adjust the crystal plane angle of the wafer to the target angle requirement; Step 3: Use diamond grinding powder and mix it with water at a weight ratio of 1:10 to 1:20 to prepare a grinding slurry. Adsorb the adjusted angle adjustment fixture onto the processing fixture and place it on the grinding equipment so that the wafer comes into contact with the grinding disc for thinning grinding. Step 4: During the grinding process, measure the angle of the grinding crystal surface and make real-time adjustments based on the changes in the crystal surface angle; Step 5: Once the entire crystal surface has been ground to the target angle, the processing is complete, and the wafer is removed.