A device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency and a method for using the device

Abstract

The present invention relates to a device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency and a method for using the device. The device provides a novel photolithography mask and a vacuum fixed base. After the wafer is coated with glue, it is exposed on the photolithography mask, and then developed and etched to prepare a deep groove structure on the wafer. The wafer is then fixed on the vacuum fixed base so that the deep groove structure on the wafer is suspended in the air; a tool is used to apply pressure from the right side of the deep groove structure of the wafer to cause the wafer to break naturally, thereby obtaining the natural cleavage surface of the wafer. The length of the natural cleavage surface of the wafer prepared by the device provided by the present invention has high consistency.

Description

Technical Field

[0001] The invention relates to a device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency and a use method thereof, belonging to the technical field of preparing the natural cleavage surface of a semiconductor laser wafer. Background Art

[0002] Semiconductor lasers are semiconductor chips that use certain semiconductor materials as working materials and generate lasers. Generally, gallium arsenide, gallium nitride, and indium phosphide semiconductor material systems are used. Like other lasers, the following three conditions must be met to generate lasers: (1) working materials; (2) the existence of an FP optical resonant cavity that allows light energy to oscillate back and forth and feedback; and (3) continuous energy injection. The working material of semiconductor lasers is mainly the quantum well active region where carrier inversion distribution occurs. The (110) natural cleavage plane of the chip is used as the FP optical resonant cavity for photon oscillation and current is used as continuous energy injection.

[0003] Currently, the most commonly used semiconductor lasers all use a ridge waveguide structure, which can not only effectively limit the lateral expansion of current and reduce the threshold current density of semiconductor lasers, but also use the refractive index guiding mechanism of the ridge waveguide to constrain the lateral light mode. Due to the light selection effect of the resonant cavity, if there is a certain deviation between the direction of the ridge waveguide and the direction of laser oscillation, some photons propagating along the ridge waveguide will deviate from the axial direction and cannot form effective laser oscillation, thereby reducing the efficiency of the laser. At the same time, the offset of the ridge waveguide will cause uneven carrier injection, causing effects such as spatial hole burning, causing the lateral light mode of the semiconductor laser to become disordered and induce high-order mode lasing. In addition, most of the current high-power semiconductor lasers have a current non-injection window. If the ridge waveguide deviation is too large, it will cause a part of the tube core on the same bar to have no window, thereby causing the entire bar to fail.

[0004] Based on the above working principle, the ridge waveguide is generally made perpendicular or nearly perpendicular to the natural cleavage plane (110) of the wafer to obtain a stable optical resonant cavity. However, since the cross section of the wafer itself is obtained by grinding after being calibrated by a crystal orientation meter, it is not a true natural cleavage plane. If the cross section of the wafer itself is used as a reference for the first step of the photolithography process, the prepared ridge waveguide will be too perpendicular to the (110) plane, that is, the deviation of the ridge waveguide is too large, resulting in failure of the entire wafer.

[0005] The ridge waveguide graphic structure is prepared through a series of photolithography and etching processes, in which the photolithography process is to transfer the pattern containing the ridge waveguide information from the photolithography mask to the photoresist on the surface of the semiconductor wafer, and then transfer the pattern to the wafer surface through development and etching processes. Therefore, the first step of photolithography is crucial to the size of the deviation.

[0006] Currently, the most commonly used method is to perform a cleavage before the first step of photolithography. The cleavage adopts the natural fracture method to obtain a real natural cleavage surface. The general process is to use a diamond knife to make a scratch with a length of 10 to 30 mm on the edge of the wafer surface. Then, by applying pressure on both sides of the scratch, it breaks naturally along the natural cleavage surface (110), thereby obtaining a fresh natural cleavage surface.

[0007] If manual process is used, the diamond knife will not be able to accurately locate the cutting position, resulting in inconsistent lengths of natural cleavage surfaces in a batch of wafers, which will have an adverse effect on subsequent processes. If cleavage equipment such as Loomis is used, the efficiency will be low and the equipment will be expensive. Summary of the invention

[0008] In view of the shortcomings of the prior art, the present invention proposes a device for preparing the natural cleavage surface of a semiconductor laser wafer with high length consistency. The device provides a new groove-type photolithography plate, the shape of the groove is consistent with the shape of the wafer, a light-transmitting area is arranged in the groove, and the rest is a light-opaque area. The wafer is exposed, developed, and corroded to obtain a deep groove structure similar to a diamond knife scratch. The wafer is then placed on a vacuum fixed base for fixation, so that the deep groove position is suspended. Then, pressure is applied by a tool at the suspended position to cause it to break along the natural cleavage surface, thereby obtaining the desired natural cleavage surface.

[0009] The present invention also provides a method for using the above-mentioned device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency.

[0010] The technical solution of the present invention is:

[0011] A device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency, comprising a photolithography mask and a vacuum fixed base,

[0012] A groove is provided on the surface of the photolithography mask, and the groove is used to limit the wafer. The shape of the groove is the same as that of the wafer. The shape of the groove includes a limiting flat edge and an arc edge connected to the limiting flat edge at both ends. The limiting flat edge is used to limit the cut surface of the wafer, and the arc edge is used to limit the circumference of the wafer. The groove includes a light-transmitting area and a light-impermeable area. The light-transmitting area is arranged at the edge of the groove, and the light-transmitting area is parallel to the limiting flat edge. The light-transmitting area is used to form a deep groove structure on the wafer with the same shape and position as the light-transmitting area.

[0013] A plurality of vacuum suction holes are arranged on the vacuum fixing base, and the vacuum suction holes are used to fix the wafer with the deep groove structure. The wafer fixed on the vacuum fixing base is cut by a tool, so that the deep groove structure of the wafer is naturally broken along the (110) direction, and a natural cleavage surface of the wafer is obtained.

[0014] In this device, the position of the light-transmitting area must be parallel to the limiting flat edge. Although the cut surface of the wafer itself is not a 110-degree plane, its deviation is very small, and the length of the deep groove itself is very small. Its force fracture will strictly follow the (110) plane fracture, so it can ensure that the (110) plane is obtained by cleavage on the wafer. The light-transmitting area set on the photolithography mask can fix the position of the deep groove on the wafer, which can ensure that the length of the natural cleavage plane is fixed, and achieve high consistency in the length of the natural cleavage plane of the wafer.

[0015] Preferably, according to the present invention, the depth of the groove is 40-50 μm higher than the thickness of the wafer, and the diameter of the groove is 1-2 mm larger than the diameter of the wafer, so that the wafer can be smoothly placed in the groove after being coated with photoresist.

[0016] Preferably according to the present invention, the length of the light-transmitting area is 20-30 mm, and the width of the light-transmitting area is 8-10 μm; further preferably, the length of the light-transmitting area is 30 mm, and the width of the light-transmitting area is 10 μm.

[0017] According to a preferred embodiment of the present invention, the shape of the bottom surface of the vacuum fixing base includes a flat edge and an arc shape connected to the flat edge at both ends.

[0018] A rib is also provided on the arc-shaped bottom surface, and the shape of the rib is adapted to the shape of the wafer. The middle of the rib is a limiting flat rib, and arc-shaped ribs are symmetrically provided at both ends of the limiting flat rib. The limiting flat rib is used to limit the cut surface of the wafer, and the arc-shaped rib is used to limit the circumference of the wafer.

[0019] Preferably, according to the present invention, the distance from the flat edge to the limiting flat edge is smaller than the distance from the limiting flat edge on the groove to the light-transmitting area, so that when the wafer with the deep groove structure is fixed on the vacuum fixing base, the deep groove structure is located outside the vacuum fixing base and is in a suspended state, which is convenient for cleaving the wafer.

[0020] According to the preferred embodiment of the present invention, a plurality of vacuum suction holes are arranged in a cross shape at the center of the bottom surface of the vacuum fixing base, and a plurality of vacuum suction holes are arranged in parallel on one side of the flat edge to ensure that the suction force at the flat edge is the largest, and this structure allows the deep groove structure on the wafer to be suspended in the air.

[0021] According to a preferred embodiment of the present invention, the photolithography mask is made of K9 glass, the opaque area is made of a chrome layer, and no coating is provided on the transparent area.

[0022] The method for using the above-mentioned device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency comprises:

[0023] (1) coating photoresist on the back side of the wafer;

[0024] (2) After pre-baking, the wafer is placed in the groove of the photolithography mask, with the side of the wafer coated with photoresist in contact with the groove, the cut surface of the wafer in contact with the limiting flat edge of the groove, and the circumference of the wafer in contact with the arc edge of the groove; the wafer is limited by the groove to ensure that the exposure position remains consistent;

[0025] (3) Expose and develop the wafer;

[0026] (4) After etching, a deep trench structure is prepared on the wafer;

[0027] (5) fixing the wafer obtained in step (4) on a vacuum fixing base so that the deep groove structure on the wafer is located outside the flat edge of the vacuum fixing base and the deep groove structure is suspended in the air;

[0028] (6) A cutting tool is used to apply pressure from the right side of the deep groove structure of the wafer, so that the wafer breaks naturally and a natural cleavage surface of the wafer is obtained.

[0029] According to the preferred embodiment of the present invention, in step (6), the tool applies pressure by vertically pressing downwards. This pressure application method can ensure that the side of the wafer with the deep groove structure contacts the tool first and starts to be subjected to force.

[0030] Preferably, in step (6), the tool contacts the right side of the deep groove structure, and the angle between the tool and the contact surface of the wafer is 2-3°, so that the deep groove structure of the wafer is naturally broken along the (110) direction to obtain a natural cleavage surface. The effect of this tilt angle is to make the tool contact the position of the deep groove structure first and start to apply pressure, so that the wafer starts to break from the position of the deep groove structure.

[0031] Preferably, according to the present invention, in step (4), the length of the deep trench structure on the wafer is 20-30 mm, the width of the deep trench structure is 8-10 μm, and the depth of the deep trench structure is 5-10 μm.

[0032] Preferably according to the present invention, in step (1), the photoresist is a positive photoresist.

[0033] Preferably, according to the present invention, in step (3), an ultraviolet lamp or a mercury lamp is used to irradiate and expose the photolithography mask.

[0034] Preferably, steps (1) to (7) are all performed under yellow light. Therefore, the photoresist on the wafer is not exposed, and subsequent stripping and re-coating are not required. The photoresist layer can be directly used for photolithography.

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

[0036] 1. The method provided by the present invention for preparing natural cleavage planes of semiconductor laser wafers with high length consistency can ensure that the positions of the prepared natural cleavage planes on the surface of the wafer are highly consistent, that is, the lengths of the natural cleavage planes have high consistency.

[0037] 2. In the device for preparing the natural cleavage surface of a semiconductor laser wafer with high length consistency provided by the present invention, the photolithography mask can ensure that the position of the deep groove structure on the wafer surface is fixed. Since the wafer breaks along the (110) plane, the fixed position of the deep groove can ensure that the length of the natural cleavage surface is fixed, that is, the length consistency of the natural cleavage surface of the wafer is good; the function of the vacuum fixed base is to allow the deep groove structure to be suspended in the air to facilitate cleavage.

[0038] 3. The method provided by the present invention for preparing the natural cleavage surface of a semiconductor laser wafer with high length consistency does not require the use of a photolithography machine. It only requires exposure using an ultraviolet lamp or a mercury lamp, and large-scale development and etching are performed after exposure, which is suitable for mass production.

[0039] 4. The method provided by the present invention for preparing the natural cleavage surface of a semiconductor laser wafer with high length consistency can directly proceed to the next step of photolithography without removing the glue and re-applying the glue, thus saving time and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a structural schematic diagram of a photolithography mask in a device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency provided by the present invention;

[0041] Figure 2 It is a schematic diagram of a top view of a photolithography mask in a device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency provided by the present invention;

[0042] Figure 3 It is a structural schematic diagram of a vacuum fixed base in a device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency provided by the present invention;

[0043] Figure 4 It is a schematic diagram of a method for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency provided by the present invention, and a surface of the wafer after development and etching;

[0044] Figure 5 It is a schematic diagram of the three-dimensional structure of a device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency provided by the present invention during wafer cleavage;

[0045] Figure 6It is a schematic diagram of the side structure of a device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency provided by the present invention during wafer cleavage;

[0046] Figure 7 It is a schematic diagram of the angle between the tool and the contact surface of the wafer in a method for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency provided by the present invention;

[0047] Figure 8 It is a schematic diagram of a wafer finally prepared by a method for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency provided by the present invention;

[0048] 1. Transparent area, 2. Opaque area, 3. Limiting flat edge, 4. Photolithography mask, 5. Vacuum suction hole, 6. Bottom of vacuum fixed base, 7. Limiting flat rib, 8. Wafer, 9. Chamfer of wafer, 10. Cutting surface of wafer, 11. Natural cleavage surface, 12. Deep groove structure, 13. Tool, 14. Vacuum fixed base, 15. Angle between the contact surface of tool and wafer, 16. Flat edge, 17. Arc-shaped rib. DETAILED DESCRIPTION

[0049] The present invention will be further defined below in conjunction with the accompanying drawings and embodiments, but is not limited thereto.

[0050] Example 1

[0051] A device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency, such as Figure 1 , Figure 2 and Figure 3 As shown, it includes a photolithography mask 4 and a vacuum fixing base 14,

[0052] A groove is provided on the surface of the photolithography mask 4, and the groove is used to limit the wafer 8. The shape of the groove is the same as that of the wafer 8. The shape of the groove includes a limiting flat edge 3 and an arc edge connected end to end with the limiting flat edge 3. The limiting flat edge 3 is used to limit the cut surface 10 of the wafer, and the arc edge is used to limit the circumference of the wafer 8. The groove includes a light-transmitting area 1 and a light-impermeable area 2. The light-transmitting area 1 is arranged at the edge of the groove, and the light-transmitting area 1 is parallel to the limiting flat edge 3. The light-transmitting area 1 is used to form a deep groove structure 12 on the wafer 8 with the same shape and position as the light-transmitting area 1.

[0053] The cut surface 10 of the wafer is obtained by cutting and grinding after being marked by a crystal orientation instrument, such as Figure 4 shown.

[0054] A plurality of vacuum suction holes 5 are provided on the vacuum fixing base 14, and the vacuum suction holes 5 are used to fix the wafer 8 having the deep groove structure 12. The wafer 8 fixed on the vacuum fixing base 14 is cut by a tool 13, so that the deep groove structure 12 of the wafer 8 is naturally broken along the (110) direction, thereby obtaining a natural cleavage surface 11 of the wafer 8.

[0055] In the photolithography mask 4, the position of the light-transmitting area 1 must be parallel to the limiting flat edge 3. Although the cut surface of the wafer 8 itself is not a 110-plane, its deviation is very small, and the length of the deep groove itself is very small. Its force fracture will strictly follow the (110) plane fracture, so it can ensure that the (110) plane is obtained by cleavage on the wafer 8. The light-transmitting area 1 set on the photolithography mask 4 can fix the position of the deep groove on the wafer 8, which can ensure that the length of the natural cleavage plane 11 is fixed, and achieve high consistency in the length of the natural cleavage plane 11 of the wafer 8.

[0056] The depth of the groove is 40-50 μm higher than the thickness of the wafer 8, and the diameter of the groove is 1-2 mm larger than the diameter of the wafer 8, so that the wafer 8 can be smoothly placed in the groove after being coated with photoresist.

[0057] The length of the light-transmitting region 1 is 30 mm, and the width of the light-transmitting region 1 is 10 μm.

[0058] The material of the photolithography mask 4 is K9 glass, and the material of the opaque area 2 is a chrome layer. No coating is provided on the transparent area 1.

[0059] like Figure 3 As shown, the shape of the bottom surface 6 of the vacuum fixed base includes a flat edge 16 and an arc connected to the flat edge 16 at both ends.

[0060] A rib is also provided on the arc-shaped bottom surface, and the shape of the rib is adapted to the shape of the wafer 8. The middle of the rib is a limiting flat rib 7, and arc-shaped ribs 17 are symmetrically provided at both ends of the limiting flat rib 7. The limiting flat rib 7 is used to limit the cut surface 10 of the wafer, and the arc-shaped rib 17 is used to limit the circumference of the wafer 8.

[0061] The distance from the flat edge 16 to the limiting flat rib 7 is smaller than the distance from the limiting flat edge 3 on the groove to the light-transmitting area 1. When the wafer 8 with the deep groove structure 12 is fixed on the vacuum fixing base 14, the deep groove structure 12 is located outside the vacuum fixing base 14 and is in a suspended state, which facilitates the cleavage of the wafer 8.

[0062] A plurality of vacuum suction holes 5 are arranged in a cross shape at the center of the bottom surface 6 of the vacuum fixing base, and a plurality of vacuum suction holes 5 are arranged in parallel on one side of the flat edge 16. The suction force at the flat edge 16 is ensured to be the largest, and this structure allows the deep groove structure 12 on the wafer 8 to be suspended in the air.

[0063] Example 2

[0064] Based on the method of the device for preparing the natural cleavage surface of the semiconductor laser wafer with high length consistency provided in Example 1, the method comprises:

[0065] (1) Coating a photoresist on the back side of the wafer 8; in step (1), the photoresist is a positive photoresist.

[0066] (2) After pre-baking, the wafer 8 is placed in the groove of the photolithography mask 4, the side of the wafer 8 coated with photoresist is in contact with the groove, the cut surface 10 of the wafer is in contact with the limiting flat edge 3 of the groove, and the circumference of the wafer 8 is in contact with the arc edge of the groove; the wafer 8 is limited by the groove to ensure that the exposure position remains consistent;

[0067] (3) Exposure and development treatment are performed on the wafer 8; after the treatment, the wafer 8 is as follows Figure 4 As shown, one side of the wafer has a chamfer 9. In step (3), an ultraviolet lamp or a mercury lamp is used to irradiate and expose the photolithography mask 4.

[0068] (4) After etching, a deep trench structure 12 is prepared on the wafer 8;

[0069] In step (4), the length of the deep trench structure 12 on the wafer 8 is 30 mm, the width of the deep trench structure 12 is 10 μm, and the depth of the deep trench structure 12 is 5 to 10 μm.

[0070] (5) fixing the wafer 8 obtained in step (4) on the vacuum fixing base 14 so that the deep groove structure 12 on the wafer 8 is located outside the flat edge 16 on the vacuum fixing base 14, and the deep groove structure 12 is suspended in the air;

[0071] (6) Using a cutter 13, pressure is applied from the right side of the deep groove structure 12 of the wafer 8 to cause the wafer 8 to fracture naturally, thereby obtaining a natural cleavage surface 11 of the wafer 8. Figure 5 and Figure 6 They are respectively a schematic diagram of the three-dimensional structure and a schematic diagram of the side structure of wafer 8 when it is cleaved.

[0072] The wafer 8 finally prepared by this method is as follows Figure 8 shown.

[0073] In step (6), the cutter 13 applies pressure in a vertical downward manner, which ensures that the side of the wafer 8 with the deep groove structure 12 contacts the cutter 13 first and begins to be subjected to force.

[0074] In step (6), if Figure 7As shown, the tool 13 contacts the right side of the deep groove structure 12, and the angle 15 between the tool and the contact surface of the wafer is 2-3°, so that the deep groove structure 12 of the wafer 8 is naturally broken along the (110) direction to obtain a natural cleavage surface 11. The effect of this tilt angle is to make the tool 13 contact the position of the deep groove structure 12 first and start to apply pressure, so that the wafer 8 starts to break from the position of the deep groove structure 12.

[0075] Steps (1) to (7) are all performed under yellow light. Therefore, the photoresist on the wafer 8 is not exposed, and there is no need to remove the photoresist or re-apply the photoresist. The photolithography can be performed directly using the photoresist layer.

[0076] The length of the natural cleavage plane 11 after cleavage is as follows Figure 8 As shown, the length of the natural cleavage surface 11 of 10 wafers 8 prepared by the method is shown in Table 1.

[0077] Table 1

[0078] Film number Length (mm) 1 20.02 2 20.04 3 20.01 4 20.04 5 20.02 6 20.01 7 20 8 20.03 9 20.05 10 20.01

[0079] It can be seen from Table 1 that the method provided in this embodiment obtains that the average length of the natural cleavage plane 11 of the wafer 8 is 20.02 mm, and the standard deviation is 0.015.

[0080] Comparative Example 1

[0081] The method of natural cleavage of wafers in the existing process is:

[0082] A diamond knife is used to scratch a scratch with a length of 10 to 30 mm on the edge of the wafer surface, and then pressure is applied on both sides of the scratch with tweezers to cause it to break naturally along the natural cleavage plane (110), thereby obtaining a fresh natural cleavage plane.

[0083] The length of the natural cleavage surface of 10 wafers prepared by this method is shown in Table 2.

[0084] Table 2

[0085]

[0086]

[0087] It can be seen from Table 2 that the method of natural cleavage of wafers in the existing process obtains an average value of 20.44 mm in length of the natural cleavage surface of the wafer, and a standard deviation of 0.679. Compared with the method provided in Example 2, it can be seen that the average value of the length of the natural cleavage surface prepared by the method of the device for preparing the natural cleavage surface of a semiconductor laser wafer with high length consistency provided in Example 2 of the present invention is 20.02 mm, and the standard deviation is 0.015, which has high consistency.

Claims

1. A device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency, It is characterized in that Including photolithography mask and vacuum fixed base, A groove is provided on the surface of the photolithography mask, and the groove is used to limit the wafer. The shape of the groove is the same as that of the wafer. The shape of the groove includes a limiting flat edge and an arc edge connected to the limiting flat edge at both ends. The limiting flat edge is used to limit the cut surface of the wafer, and the arc edge is used to limit the circumference of the wafer. The groove includes a light-transmitting area and a light-impermeable area. The light-transmitting area is arranged at the edge of the groove, and the light-transmitting area is parallel to the limiting flat edge. The light-transmitting area is used to form a deep groove structure on the wafer with the same shape and position as the light-transmitting area. A plurality of vacuum suction holes are arranged on the vacuum fixing base, and the vacuum suction holes are used to fix the wafer with the deep groove structure. The wafer fixed on the vacuum fixing base is cut by a tool, so that the deep groove structure of the wafer is naturally broken along the (110) direction, and a natural cleavage surface of the wafer is obtained.

2. A device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency according to claim 1, It is characterized in that The depth of the groove is 40-50 μm higher than the thickness of the wafer; the diameter of the groove is 1-2 mm larger than the diameter of the wafer.

3. The device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency according to claim 1, It is characterized in that The length of the light-transmitting area is 20-30 mm, and the width of the light-transmitting area is 8-10 μm.

4. The device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency according to claim 3, It is characterized in that The length of the light-transmitting area is 30 mm, and the width of the light-transmitting area is 10 μm.

5. The device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency according to claim 1, It is characterized in that The shape of the bottom surface of the vacuum fixed base includes a flat edge and an arc connected to the flat edge at both ends. A rib is also provided on the arc-shaped bottom surface, and the shape of the rib is adapted to the shape of the wafer. The middle of the rib is a limiting flat rib, and arc-shaped ribs are symmetrically provided at both ends of the limiting flat rib. The limiting flat rib is used to limit the cut surface of the wafer, and the arc-shaped rib is used to limit the circumference of the wafer.

6. The device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency according to claim 5, It is characterized in that The distance from the flat edge to the limiting flat rib is smaller than the distance from the limiting flat edge on the groove to the light-transmitting area.

7. The device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency according to claim 5, It is characterized in that A plurality of vacuum suction holes are arranged in a cross shape at the center of the bottom surface of the vacuum fixing base, and a plurality of vacuum suction holes are also arranged in parallel on one side of the flat edge.

8. A method for using the device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency as described in any one of claims 5 to 7, It is characterized in that The method includes: (1) coating photoresist on the back side of the wafer; (2) After pre-baking, the wafer is placed in the groove of the photolithography mask, with the side of the wafer coated with photoresist in contact with the groove, the cut surface of the wafer in contact with the limiting flat edge of the groove, and the circumference of the wafer in contact with the arc edge of the groove; (3) Expose and develop the wafer; (4) After etching, a deep trench structure is prepared on the wafer; (5) fixing the wafer obtained in step (4) on a vacuum fixing base so that the deep groove structure on the wafer is located outside the flat edge of the vacuum fixing base and the deep groove structure is suspended in the air; (6) A cutting tool is used to apply pressure from the right side of the deep groove structure of the wafer, so that the wafer breaks naturally and a natural cleavage surface of the wafer is obtained.

9. A method for using the device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency according to claim 8, It is characterized in that In step (6), the tool applies pressure by pressing vertically downward.

10. A method for using the device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency according to claim 8, It is characterized in that In step (6), the tool contacts the right side of the deep groove structure, and the angle between the tool and the contact surface of the wafer is 2-3°, so that the deep groove structure of the wafer is naturally broken along the (110) direction to obtain a natural cleavage surface.

11. A method for using the device for preparing a natural cleavage surface of a semiconductor laser wafer with high length consistency according to claim 8, It is characterized in that In step (4), the length of the deep trench structure on the wafer is 20-30 mm, the width of the deep trench structure is 8-10 μm, and the depth of the deep trench structure is 5-10 μm.

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