GaAs wafer cleavage auxiliary cracking device and method

Abstract

The invention relates to a GaAs wafer cleavage auxiliary cracking device and method, belongs to the technical field of semiconductor laser manufacturing, and solves the technical problem of poor cleavage cracking quality of a GaAs wafer thick piece, the cleavage auxiliary cracking device is of an integral structure, and a certain angle is formed between the upper surface and the bottom surface of the cleavage auxiliary cracking device. And a wafer groove and a step surface are arranged on the substrate. And the bottom of the wafer groove is parallel to the upper surface of the wafer groove. The step surface is a right-angle groove, and the bottom surface of the right-angle groove is parallel to the bottom surface of the auxiliary cracking device and lower than the bottom of the wafer groove; the vertical surface of the right-angle groove is tangent to the wafer groove and intersects with the upper surface of the auxiliary cracking device and the bottom of the wafer groove to form two straight lines parallel to the bottom surface of the right-angle groove. And exhaust holes are formed, and the exhaust holes are used for vacuum adsorption and fixation of the GaAs wafer to be cleaved and cracked. The cleavage auxiliary cracking device is used for cleavage auxiliary cracking of the GaAs wafer with the thickness of 450-600 [mu] m.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor laser manufacturing, and in particular relates to a GaAs wafer cleavage auxiliary cracking device and method. Background Art

[0002] Gallium arsenide (GaAs) semiconductor lasers have the advantages of high output power, high power conversion efficiency, small size and high reliability, and have been widely used in optical communications, optical information storage, pumped solid lasers, material processing, laser medical treatment and other fields. Gallium arsenide (GaAs) semiconductor lasers generally adopt an edge-emitting structure, with gallium arsenide as the medium, and the cleavage surface of gallium arsenide as the resonant cavity reflection surface. The particle beam is inverted by means of electrical injection excitation, and the electron and hole recombination generates stimulated radiation that oscillates and amplifies in the cavity to achieve light emission from the cleavage surface.

[0003] As a very important process technology in the preparation of gallium arsenide (GaAs) semiconductor lasers, the wafer thickness is in the range of 450-600um. The quality of cleavage and cutting will directly affect the alignment of the lithography pattern and the wafer orientation in the subsequent process steps, which will in turn affect the divergence angle, output power, etc. of the gallium arsenide (GaAs) semiconductor laser.

[0004] At present, the main cleavage methods of GaAs wafer slices (thickness ≤ 200um) are: 1. Diamond knife end face slicing + splitting with a cleaver; 2. Diamond knife end face slicing + roller splitting.

[0005] When the GaAs wafer thickness increases to 450-600um, the cleaver pressure in the first method or the roller pressure in the second method cannot separate the wafer into pieces. Summary of the invention

[0006] In order to overcome the problem of poor quality of cleavage cracking of thick GaAs wafers, the present invention provides a GaAs wafer cleavage auxiliary cracking device and method.

[0007] The technical solution adopted by the present invention to solve the technical problem is:

[0008] A GaAs wafer cleavage auxiliary cracking device is used for cleavage auxiliary cracking of GaAs wafers with a thickness of 450um to 600um; it is an integral structure, and its top and bottom surfaces form a certain angle. An exhaust hole is arranged.

[0009] Wafer grooves and step surfaces are arranged on the top.

[0010] The wafer groove is a cylindrical groove, the bottom of which is parallel to the top, and matches the outer shape structure of the GaAs wafer to be cleaved and assisted in cracking, and is used for vacuum adsorption of the GaAs wafer to be cleaved and assisted in cracking.

[0011] The step surface is a right-angle groove, the bottom surface of the right-angle groove is parallel to the bottom surface of the auxiliary cracking device and is lower than the bottom of the wafer groove; the vertical surface of the right-angle groove cuts through the wafer groove, and the vertical surface of the right-angle groove intersects with the upper surface of the auxiliary cracking device and the bottom of the wafer groove, and the intersection forms two straight lines, which are parallel to the bottom surface of the right-angle groove. The part of the vertical surface of the right-angle groove located below the bottom of the wafer groove is a steel beam. The width of the bottom surface of the right-angle groove corresponds to the cutting width of the GaAs wafer.

[0012] The exhaust hole is provided with two exhaust hole openings, the inner exhaust hole opening is located at the bottom of the wafer groove, the outer exhaust hole opening is located at the side of the auxiliary cracking device, and the outer exhaust hole opening is connected to an external vacuum device. The exhaust hole is used for vacuum adsorption and fixation of the GaAs wafer to be cleaved and cracked.

[0013] The GaAs wafer cleavage auxiliary cracking device has an angle between the top and bottom surfaces of the auxiliary cracking device of 2° to 4°.

[0014] A GaAs wafer cleavage assisted cracking method based on a GaAs wafer cleavage assisted cracking device comprises the following steps:

[0015] Scribe lines on the wafer in the cleavage direction to form cutting edge lines;

[0016] Place the wafer in the wafer slot with the cut edge scribe line aligned with the steel beam;

[0017] Vacuum adsorption to fix the wafer;

[0018] A certain pressure is applied at one end of the wafer cutting edge scribing position to assist cracking, so that the cutting edge is naturally cracked and separated along the wafer direction at the scribing position.

[0019] In the above-mentioned GaAs wafer cleavage-assisted cracking method, the wafer groove size matches the 2-inch, 3-inch or 4-inch GaAs wafer thick slice.

[0020] In the above-mentioned GaAs wafer cleavage-assisted cracking method, the length of the trimming line is 2 mm to 6 mm.

[0021] In the above-mentioned GaAs wafer cleavage-assisted cracking method, the length of the trimming line is 5 mm.

[0022] The target cutting edge width of the GaAs wafer cleavage-assisted cracking method is 5 mm to 7 mm.

[0023] The beneficial effects of the present invention are:

[0024] A GaAs wafer cleavage auxiliary cracking device is provided for GaAs wafers with a thickness in the range of 450um to 600um that cannot be cleaved and cracked by conventional cleavage methods. The wafer trimming position is aligned with a steel beam by marking, and the wafer is fixed by vacuum adsorption. There is a certain height difference between the trimming edge and the step surface. A certain pressure is applied at one end of the wafer trimming edge marking position to assist cracking, so that the trimming edge is naturally cracked and separated along the wafer direction at the marking position, and the end face is flush and undamaged.

[0025] A GaAs wafer cleavage auxiliary cracking device solves the problem of thick-slice cleavage edge cutting of GaAs wafers by combining thin-slice cleavage equipment with thick-slice cleavage auxiliary cracking equipment.

[0026] A GaAs wafer cleavage auxiliary cracking device can cleave the edge of a GaAs wafer thick slice of any width by adjusting the step surface width. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of a gallium arsenide (GaAs) wafer cleavage auxiliary cracking device according to embodiment 1 of the present invention;

[0028] Figure 2 This is a front view of the auxiliary cracking device of the first embodiment of the invention;

[0029] Figure 3 This is a left view of the auxiliary cracking device of the first embodiment of the invention;

[0030] Figure 4 This is a cross-sectional view of the AA plane of the front view of the auxiliary cracking device of the first embodiment of the invention;

[0031] Figure 5 This is a schematic diagram of thick slice cleavage using the auxiliary cracking device according to Example 1 of the invention.

[0032] Figure numerals: 1. Inner opening of exhaust hole, 2. Outer opening of exhaust hole, 3. Wafer groove, 4. Steel beam, 5. Step surface, 6. GaAs wafer, 7. Trimming and scribing line, 8. Auxiliary cracking device. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Embodiment 1

[0035] refer to Figures 1 to 5 , an example of a gallium arsenide (GaAs) wafer thick slice cleavage auxiliary cracking device includes: an exhaust hole inner opening 1, an exhaust hole outer opening 2, a wafer groove 3, a steel beam 4, a step surface 5, and a GaAs wafer thick slice 6.

[0036] The inner opening 1 of the exhaust hole is circular and is connected to the air pipe of the vacuum equipment when in use to provide suction force for vacuum adsorbing the wafer;

[0037] The exhaust hole outer port 2 is connected to the exhaust hole inner port 1, and the wafer is vacuum-absorbed to fix the wafer. When pressure is applied to the cut edge of the thick wafer, the cut edge is successfully cleaved and separated;

[0038] The wafer groove 3 is circular with a flat surface, matching the size of the wafer, and serves to limit the position of the wafer. It is combined with the exhaust hole outer port 2 to vacuum absorb and fix the wafer;

[0039] The steel beam 4 is flat and has no defects, and its plane is higher than the step surface 5;

[0040] The step surface 5 maintains a certain height difference with the steel beam surface. In addition, the width of the step surface corresponds to the trimming width. The target trimming width requirement can be achieved by adjusting the step surface width.

[0041] The GaAs wafer thick piece 6 can be 2 inches, 3 inches, 4 inches, etc. in size, and can be any thickness between 450-600um, with a flat edge parallel or perpendicular to the crystal direction;

[0042] The trimming line 7 is parallel or perpendicular to the flat edge of the GaAs wafer thick slice 6, has a length of 2-5 mm, and is required to be aligned with the steel beam 4 when cleaving the slice;

[0043] The steel beam angle θ is the angle between the plane where the steel beam is located and the vertical plane, which is in the range of 92°-94°;

[0044] This embodiment can realize the cleavage separation of a 3-inch GaAs wafer with a 4mm width, and the end surface is flat and undamaged. At the same time, it is found in the actual cleavage process that increasing the length of the edge scribe line is conducive to the edge cleavage separation. Experimental data show that when the edge scribe line length is increased to 5mm, the pressure required to be applied is smaller, and the edge is easier to cleave.

[0045] Embodiment 2

[0046] In the second embodiment, refer to Figure 2 , adjust the width of the step surface 5 to make the target cutting edge width 5mm, 6mm, and 7mm. The actual cleavage process shows that the larger the cutting edge width, the smaller the pressure required to be applied, and the end face of the cutting edge is smooth and undamaged.

[0047] Embodiment 3

[0048] In Example 3, reference Figure 4 , the steel beam angle θ was adjusted to 93° and 94°. The actual cleavage process showed that the increase of the steel beam angle θ did not significantly change the actual pressure, and the end face of the cut edge was smooth and undamaged.

Claims

1. A GaAs wafer cleavage auxiliary cracking device, characterized in that: Used for cleavage and auxiliary cracking of GaAs wafers with a thickness of 450um to 600um; it is an integral structure with a certain angle between the top and bottom surfaces; exhaust holes are provided; A wafer groove (3) and a step surface (5) are arranged on the auxiliary cracking device (8); The wafer groove (3) is a cylindrical groove, the bottom of which is parallel to the top; it matches the outer structure of the GaAs wafer (6) to be cleaved and assisted in cracking, and is used for vacuum adsorption of the GaAs wafer (6) to be cleaved and assisted in cracking; The step surface (5) is a right-angle groove, the bottom surface of the right-angle groove is parallel to the bottom surface of the auxiliary cracking device (8) and is lower than the bottom of the wafer groove (3); the vertical surface of the right-angle groove cuts through the wafer groove (3), the vertical surface of the right-angle groove intersects with the upper surface of the auxiliary cracking device (8) and the bottom of the wafer groove (3), and the intersection forms two straight lines, and the two straight lines are parallel to the bottom surface of the right-angle groove; the part of the vertical surface of the right-angle groove located below the bottom of the wafer groove (3) is a steel beam (4); the width of the bottom surface of the right-angle groove corresponds to the cutting width of the GaAs wafer (6); The exhaust hole is provided with two exhaust hole openings, the exhaust hole inner opening (1) is located at the bottom of the wafer groove (3), the exhaust hole outer opening (2) is located at the side of the auxiliary cracking device (8), and the exhaust hole outer opening (2) is connected to an external vacuum device; the exhaust hole is used for vacuum adsorption and fixation of the GaAs wafer (6) to be cleaved and cracked.

2. The GaAs wafer cleavage auxiliary cracking device according to claim 1, characterized in that: The angle between the top and bottom surfaces of the auxiliary cracking device (8) is 2° to 4°.

3. A GaAs wafer cleavage-assisted cracking method based on the GaAs wafer cleavage-assisted cracking device according to claim 1 or 2, characterized in that: The following steps are involved: Marking the wafer along the cleavage direction to form a cutting edge marking line (7); Place the wafer in the wafer slot, aligning the trimming line (7) with the steel beam; Vacuum adsorption to fix the wafer; A certain pressure is applied at one end of the wafer cutting edge scribing position to assist cracking, so that the cutting edge is naturally cracked and separated along the wafer direction at the scribing position.

4. The GaAs wafer cleavage assisted cracking method according to claim 3, characterized in that: The wafer slot size matches a 2-inch, 3-inch or 4-inch GaAs wafer thick piece (6).

5. The GaAs wafer cleavage assisted cracking method according to claim 3, characterized in that: The length of the trimming line (7) is 2 mm to 6 mm.

6. The GaAs wafer cleavage-assisted cracking method according to claim 3, characterized in that: The length of the trimming line (7) is 5 mm.

7. The GaAs wafer cleavage-assisted cracking method according to claim 3, characterized in that: The target cutting edge width is 5mm to 7mm.

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