Method for obtaining monocrystal diamond (111) surface wafer by using double-pulse-width laser

Abstract

The invention belongs to the technical field of crystal processing, and relates to a method for obtaining a single crystal diamond (111) surface wafer by using double-pulse-width laser. Femtosecond laser and picosecond laser are adopted for machining and stripping the blocky single crystal diamond to obtain a first crystal face (111), then femtosecond laser and picosecond laser are continuously adopted for machining and stripping the remaining blocky single crystal diamond, and the blocky single crystal diamond is obtained; the process for obtaining the crystal face (111) comprises the following steps of: scanning femtosecond laser on the crystal face (111) to process a plurality of graphitization modification lines which are full of the crystal face (111) and are parallel to each other, wherein the graphitization modification lines are parallel to the crystal orientation of a diagonal line [110] of the crystal face (001); carrying out scanning processing along the graphitization modification line by utilizing picosecond laser, so as to form a leap crack on the basis of the graphitization modification line of the crystal face (111); and then stripping is carried out. By means of the method, the wafer with the complete (111) face can be obtained through cutting in the ultra-thick (001) CVD monocrystal diamond.

Description

Technical Field

[0001] The invention belongs to the technical field of crystal processing and relates to a method for obtaining a single crystal diamond (111) surface wafer by using a double-pulse width laser. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] The (111) crystal plane of diamond has shown significant advantages in the field of semiconductors and electronic devices. First, compared with other crystal planes, the (111) plane has a higher doping efficiency and a larger surface dangling bond density, which makes it have outstanding potential in the application of hydrogen-terminated diamond electronic devices. Secondly, the crystal plane has a high atomic density and strong bonding strength, and a low chemical corrosion rate, which is conducive to improving the stability and life of the material. In addition, boron doping can further optimize the electrical properties of the (111) plane, such as accelerating the growth rate, increasing the carrier density and enhancing the conductivity, which is crucial for high-temperature, high-frequency, and high-power semiconductor devices. When the diamond (111) plane is used as an epitaxial substrate, its ultra-high thermal conductivity (22W / cm·K) can effectively alleviate the self-heating effect of GaN-based devices and improve the output power and reliability. However, during the growth and epitaxy process, the growth of the diamond (111) surface is easily affected by twins and stacking faults, which limits the thickness of the diamond and the surface roughness of the grown surface is also high. Even after the (111) surface is polished, tiny cracks or steps will remain, resulting in poor surface quality of the diamond. Although some progress has been made in recent years, it is still difficult to achieve the growth of a (111) surface layer with a thickness of more than 100nm and a low surface roughness.

[0004] According to the inventors' research, the commonly used method for obtaining the (111) crystal plane on a diamond single crystal grown on other crystal planes is laser cutting. The core of laser cutting technology is to use a high-energy-density laser beam to locally heat or physically modify the diamond material, thereby inducing stress changes inside the material and ultimately achieving crack propagation along a specific crystal plane. However, the inventors have found that this method also has many shortcomings: 1. Laser cutting requires continuous high-power power supply, high energy consumption, and higher cost than traditional cutting methods; 2. The high temperature generated during laser cutting may cause a sub-surface damage layer inside the material, which needs to be removed by other methods, increasing the complexity of the process; 3. Although laser cutting significantly reduces material loss compared to traditional mechanical cutting, it will inevitably lose some expensive single-crystal diamond materials; 4. Laser cutting has strict requirements on the quality of diamond. If defects such as dislocations appear inside the diamond, cracks may extend along the defects during cutting, resulting in irregular fractures; 5. It is difficult to achieve layered adjustment of single-pulse laser energy, the heat-affected zone is easy to expand, the peeling effect is uneven, and steps or rough boundaries are easy to be generated; 6. At the same time, the thickness that can be processed by femtosecond laser of CVD single-crystal diamond is subject to the comprehensive constraints of energy attenuation, focus drift and defect amplification effect. The current industrial application is mainly sub-millimeter level, and thick diamond cutting is still in the laboratory exploration stage. In addition, the crack length generated by a single laser processing path is not enough to extend the entire (111) crystal plane, and it is impossible to directly obtain a (111) surface wafer. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, the present invention aims to provide a method for obtaining a single crystal diamond (111) face wafer using a dual-pulse width laser, which can cut a complete (111) face wafer in an ultra-thick (001) CVD single crystal diamond.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, a method for obtaining a single crystal diamond (111) surface wafer using a dual pulse width laser comprises the following steps:

[0008] Provide (001) CVD bulk single crystal diamond with a thickness of not less than 5mm;

[0009] The block-shaped single crystal diamond is processed and peeled off by using a femtosecond laser and a picosecond laser to obtain a first (111) crystal plane, and then the remaining block-shaped single crystal diamond is processed and peeled off by using a femtosecond laser and a picosecond laser to obtain a single crystal diamond (111) plane wafer;

[0010] The process of using femtosecond laser and picosecond laser for processing and peeling to obtain the (111) crystal plane is as follows: first, a femtosecond laser is passed through the (001) crystal plane of the block single crystal diamond to scan and process a plurality of parallel graphitization modification lines that are distributed throughout the (111) crystal plane, and the graphitization modification lines are parallel to the diagonal [-110] crystal direction of the (001) crystal plane; then a picosecond laser is used to scan and process along the graphitization modification lines to form a leaping crack on the basis of the graphitization modification lines of the (111) crystal plane; and then peeling is performed.

[0011] Specifically, the process of using femtosecond laser and picosecond laser for processing and peeling to obtain (111) crystal plane is as follows: passing the femtosecond laser through the (001) crystal plane of the block single crystal diamond, and aligning its focus to a preset depth of the (111) crystal plane inside the block single crystal diamond; scanning and processing the laser beam of the femtosecond laser in a line scanning manner, with the crystal direction [-110] parallel to the diagonal line of the (001) crystal plane as a first preset path, so that a first graphitization modification line is formed inside the block single crystal diamond; then, by gradually reducing the focus depth of the laser beam of the femtosecond laser, scanning and processing the laser beam of the femtosecond laser in parallel to the first preset path, so that a plurality of graphitization modification lines parallel to the first graphitization modification line are formed inside the block single crystal diamond, until the graphitization modification lines cover the entire (111) crystal plane;

[0012] Picosecond laser is used to scan along the graphitization modification line, so that a leaping crack is formed on the basis of the graphitization modification line of the (111) crystal plane.

[0013] The present invention uses a dual-pulse width laser to focus on the inside of a block diamond with a thickness of 5 mm or more to form interconnected and (111) crystal plane-crossing cracks. The closely arranged cracks can significantly reduce the binding force inside the diamond crystal, and the diamond crystal can be successfully separated under the condition of applying external force.

[0014] In some embodiments, the thickness of the CVD bulk single crystal diamond (001) crystal plane is 5 to 7 mm.

[0015] In some embodiments, the CVD bulk single crystal diamond is in a cube shape or a quasi-cube shape. The cube shape or the quasi-cube shape means that the ratio of length, width and thickness is 0.9 to 1.1:0.9 to 1.1:1. Among them, the thickness can be the thickness of the (001) crystal plane of the single crystal diamond, and the length and width can be the length and width of the (001) crystal plane of the single crystal diamond, respectively.

[0016] In some embodiments, the femtosecond laser is perpendicular to the (001) crystal plane of the diamond stripping block. Setting the femtosecond laser perpendicular to the (001) crystal plane of the diamond stripping block can concentrate energy, improve processing efficiency, ensure processing accuracy, reduce reflection loss, and protect equipment.

[0017] In some embodiments, the bulk single crystal diamond is natural diamond or artificial diamond.

[0018] In some embodiments, the number of graphitized modified lines is 4 to 10, and the distances between adjacent graphitized modified lines are equal, which is beneficial for connecting the leaping cracks and covering the (111) crystal plane.

[0019] In some embodiments, the (001) crystal plane of the block single crystal diamond is a polished surface, which can better achieve successful laser injection and scanning.

[0020] In some embodiments, after processing a graphitized modified line, the laser beam is directed along After the crystal rises, the next graphitization modification line is processed.

[0021] In some embodiments, when stripping the single crystal diamond, the single crystal diamonds on both sides of the leaping crack are separated by a method of glue coating combined with external force separation. Specifically, after the two sides of the leaping crack of the single crystal diamond are bonded and fixed, a tensile force is applied to peel it off. The diamond is separated by a method of glue coating combined with external force separation, while the non-diamond layer is efficiently removed, the integrity and functionality of the diamond are protected to the maximum extent. Specifically, after stripping, the two single crystal diamonds that are pulled apart are separated from the platform using an organic solvent, and the glue is removed.

[0022] In some embodiments, after stripping, the stripping surface of the diamond is cleaned. The graphite remaining on the (111) crystal surface of the diamond is removed by cleaning to expose the (111) crystal surface. Specifically, the cleaning method is: immerse the diamond sample in a cleaning solution, treat it at room temperature for a period of time, and then use ultrasonic cleaning to remove the graphite remaining on the stripping surface. Specifically, the cleaning solution is a mixture of one or more of concentrated sulfuric acid, hydrogen peroxide, concentrated nitric acid, acetone, and isopropanol. A strong oxidizing acid is used to selectively oxidize graphite to carbon dioxide without corroding the inert diamond. The shock wave released by the cavitation bubbles generated by the high-frequency vibration of the ultrasound wave can directly act on the graphite on the stripping surface of the diamond, avoiding physical contact and ensuring the quality and integrity of the diamond sample.

[0023] In some embodiments, the surface area of ​​the obtained bulk single crystal diamond (111) crystal plane is equal to √3 of the vertical cross-sectional area of ​​the corresponding scanning path of the bulk single crystal diamond.

[0024] The present invention continues to use femtosecond laser and picosecond laser to process and peel off the remaining block-shaped single crystal diamond for multiple times, so as to obtain multiple single crystal diamond (111) surface wafers.

[0025] On the other hand, a system for obtaining a single crystal diamond (111) surface wafer using a dual-pulse width laser is used to implement the above method, comprising:

[0026] A femtosecond laser source, used for generating femtosecond laser;

[0027] A femtosecond laser source moving device, used to fix the femtosecond laser source and control the femtosecond laser source to move along a set path;

[0028] A picosecond laser source, used for generating picosecond laser;

[0029] A picosecond laser source moving device, used to fix the picosecond laser source and control the picosecond laser source to move along a set path;

[0030] A diamond fixing device, used for fixing diamond;

[0031] The stripping device is used to strip the diamond after laser cutting.

[0032] The beneficial effects achieved by one or more technical solutions of the present invention are as follows:

[0033] The present invention uses a block single crystal diamond with a (100) crystal plane as a growth plane, uses a femtosecond laser to perform a scan inside the diamond once, so that the (111) crystal plane is covered with modification lines, and then uses a picosecond laser to perform a second scan inside the diamond along the modification lines to form internal leap-over cracks that are interconnected and cover the entire (111) crystal plane. Under the action of tension, the diamond crystal is separated. This method can obtain a group of (double-sided) (111) crystal planes, and at the same time, the material processing range is small, the loss is low, the efficiency is high, and the obtained (111) crystal plane is the largest.

[0034] The present invention focuses a dual-pulse width laser into the interior of the diamond to achieve cutting. The dual-pulse width laser technology is used to avoid contact and friction between traditional mechanical cutting tools and diamonds, and to protect the integrity and mechanical properties of diamonds to the maximum extent. At the same time, compared with single pulse width, dual-pulse width laser (femtosecond laser and picosecond laser) has multiple advantages: in terms of energy regulation, the energy distribution of dual-pulse width laser is more flexible, and the operation of first excitation and then supplementary punching can be realized; in terms of thermal impact control, short pulse width laser punches out the initial structure, and long pulse width laser performs "gentle" peeling, which can effectively reduce thermal cracking; in terms of material response efficiency, the processing efficiency is improved through multiple mechanisms; in terms of structural integrity, the interlayer structure can be smoothly processed and the surface roughness can be reduced; in terms of precision, the method of shallow punching first and deep peeling later is adopted, which is convenient for fine control of the thickness and position of the peeling layer. Therefore, the dual-pulse width laser technology has the advantages of high efficiency, low loss, and high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0036] Figure 1 It is a schematic diagram of a flow chart in an embodiment of the present invention.

[0037] Figure 2 Schematic diagram of the structure of the diamond crystal used in the embodiment of the present invention.

[0038] Figure 3 It is a schematic diagram of focusing a femtosecond laser to a preset depth inside a diamond in an embodiment of the present invention.

[0039] Figure 4 This is a schematic diagram of forming a first modified line by scanning along a preset path once using a femtosecond laser in an embodiment of the present invention.

[0040] Figure 5 It is a schematic diagram of a surface modification line after a single scan along a preset path using a femtosecond laser according to an embodiment of the present invention.

[0041] Figure 6 It is a schematic diagram of forming a leaping crack on the peeling surface after a second scanning along the modified line using a picosecond laser according to an embodiment of the present invention.

[0042] Figure 7 This is a schematic diagram of the interconnected cracks on the peeling surface after a second scan along the modified line using a picosecond laser in an embodiment of the present invention.

[0043] Figure 8 Schematic diagram of the diamond peeling surface structure according to an embodiment of the present invention.

[0044] Fig. 9 Schematic diagram of a diamond stripping block according to an embodiment of the present invention.

[0045] Fig.10 Schematic diagram of a diamond (111) surface wafer according to an embodiment of the present invention.

[0046] Wherein: 100-bulk single crystal diamond; 101-bulk single crystal diamond (001) crystal plane; 102-bulk single crystal diamond (111) crystal plane; 103-diamond peeling block; 104-diamond (111) surface wafer; 200-femtosecond laser beam; 201-laser scanning path; 202-path of laser beam changing focus depth; 203-laser modification line inside bulk single crystal diamond; 204-picosecond laser beam; 205-crack. DETAILED DESCRIPTION

[0047] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0048] Example

[0049] A method for obtaining a single crystal diamond 100 (111) face wafer 104 using a double pulse width laser, such as Figures 1 to 10 As shown, the following steps are included:

[0050] S1 , directing a femtosecond laser beam 200 having a transmission wavelength perpendicular to the (001) crystal plane 101 of the bulk single crystal diamond, and positioning its focus at a preset depth of the (111) crystal plane 102 inside the bulk single crystal diamond 100 .

[0051] S2, the femtosecond laser beam performs a single path 201 line scan, so that the inner layer of the block single crystal diamond 100 directly forms a first graphitized modified line 202, and the focus depth of the femtosecond laser beam is changed along the preset path 201, and the femtosecond laser beam continues to perform a single path 201 line scan, so that the second graphitized modified line 202 is formed inside the block single crystal diamond 100, and step S2 is repeated until the modified line covers the entire (111) crystal plane 102.

[0052] S3, the picosecond laser beam 204 performs a second scan along the modified line 202, so that a leaping crack 205 is formed on the (111) crystal plane 102, and adjacent leaping cracks are connected to each other.

[0053] S4, fixing the block of single crystal diamond 100, so as to separate the block of single crystal diamond 100 along the direction of the crack 205 under the action of tension, and obtaining a diamond peeling block 103.

[0054] S5, remove the diamond stripping block 103, clean the graphite on the surface of the diamond, and dry it after cleaning for later use.

[0055] The above steps S1 to S5 are implemented until a group of (111) crystal planes on the diamond peeling block 103 are obtained.

[0056] S6, randomly select one of the diamond stripping blocks 103, focus the laser beam to a preset depth of the (001) crystal plane inside the diamond stripping block 103, and repeat the above steps S2 to S5 until a diamond (111) surface wafer 104 is obtained.

[0057] A femtosecond 200 and picosecond 204 dual-pulse laser is used. The pulsed laser emitted by the laser is injected at a preset depth, the focal depth is changed along a preset path 202, and it moves along a preset path 201 to form an extended crack 205 along the preset peeling (111) crystal plane 102 in the diamond. The cracks 205 are connected to each other to form a peeling layer 102.

[0058] The focus of the femtosecond laser is vertically positioned at 9 / 10 of the single crystal diamond thickness downward from the incident surface.

[0059] like Figure 2 The figure shows the structure of the block single crystal diamond to be processed in this embodiment, wherein the (001) plane 101 (thickness of 5 to 7 mm) is used as the growth surface of the CVD single crystal.

[0060] The bulk single crystal diamond 100 may be an insulating natural diamond or an insulating artificial diamond.

[0061] In order to achieve successful laser incidence and scanning, the (001) surface 101 of the block diamond crystal 100 should be a polished surface.

[0062] like Figure 3 , Figure 4 and Figure 5 As shown, in this embodiment, a schematic diagram of using a femtosecond laser to focus at a preset depth inside the diamond, a schematic diagram of using a femtosecond laser to scan once along a preset path to form a first modified line, and a schematic diagram of using a femtosecond laser to scan once along a preset path to form a surface modified line. In one embodiment of the present invention, the preset scanning path 201 is along the diagonal line of the (001) crystal plane 101 of the block single crystal diamond 100, and the first graphitization modified line 203 is formed by line scanning. The laser beam is along Crystalline diamond thickness The preset scanning path 201 is along the diagonal line of the (001) crystal plane 101 of the block single crystal diamond 100, and a second graphitization modified line 203 is formed by line scanning. This step is repeated to make the modified line 203 cover the entire (111) crystal plane.

[0063] like Figure 6 and Figure 7 As shown, a schematic diagram of the formation of a leaping crack on the peeling surface after the picosecond laser is scanned twice along the modified line in this embodiment and a schematic diagram of the interconnection of cracks on the peeling surface after the picosecond laser is scanned twice along the modified line. In one embodiment of the present invention, the picosecond laser beam 204 is scanned twice along the modified line 203, and a leaping crack 205 is formed by the second scanning, and the leaping cracks 205 are interconnected to cover the entire (111) crystal plane.

[0064] The block single crystal diamond crystal 100 scanned by the femtosecond laser beam 200 is coated with special glue on both sides and then bonded to the upper and lower surfaces of the separation platform, and a pulling force is applied to the separation platform to separate the block single crystal diamond crystal 100.

[0065] The block-shaped single crystal diamond 100 is peeled off by applying glue and then separating by external force, thereby protecting the interior of the diamond from being damaged.

[0066] The focus of the femtosecond laser is again positioned vertically at 9 / 10 the thickness of the single crystal diamond below the incident plane.

[0067] Figure 8 Schematic diagram of the structure of the diamond peeling surface under an embodiment of the present invention. In one embodiment of the present invention, the surface area of ​​the obtained diamond (111) crystal plane 102 is equal to √3 of the vertical cross-sectional area of ​​the block single crystal diamond crystal 100 corresponding to the scanning path 200.

[0068] The separated diamond stripping block 102 is separated from the separation platform using an organic solvent, and then subjected to debonding treatment, cleaned, and air-dried for later use. Chemical reagents such as dimethylformamide are used to assist debonding during the debonding process, which shortens the debonding time, has significant effects, and can improve efficiency.

[0069] In step S5, the diamond stripping block is first immersed in a cleaning solution, treated at room temperature for a period of time, and then cleaned with ultrasonic waves generated by an ultrasonic generator to remove the graphite remaining on the surface of the stripping surface, and then dried for later use. Of course, the cleaning solution is not limited to a mixture of concentrated sulfuric acid and concentrated nitric acid. For example, in one embodiment of the present invention, after being placed in acetone for a period of time, the graphite is cleaned with the assistance of an ultrasonicator, which can also achieve a beneficial effect.

[0070] In addition to the methods for separating the diamond crystal 100 mentioned in S4 and S5 above, in one embodiment of the present invention, the diamond block 100 after laser scanning is placed in an ultrasonic generator containing H plasma solution, the ultrasonic generator is turned on to generate ultrasonic waves, and the electrolysis device is turned on to reduce the diamond crystal 100.

[0071] During the ultrasonic cleaning process, the high-frequency cavitation effect formed in the liquid medium can directionally dissociate the CO polar bonding structure of graphene oxide. This non-contact treatment mechanism can effectively avoid the introduction of foreign pollutants while improving the removal efficiency of the amorphous carbon phase, and fully guarantee the characteristics of the diamond stripping block 102 itself. Especially in the H plasma environment, the microjet effect generated by ultrasonic cavitation can significantly enhance the desorption energy of the surface adsorbed carbon atoms, so that the sp at the interface between the stripping layer 102 and the diamond crystal 100 2 The hybrid carbon phase is separated layer by layer at the atomic level. This synergistic effect can reduce the interfacial binding energy by about 35%, thereby achieving high-cleanliness interface preparation at the nanoscale.

[0072] The specific crystal plane of the present invention is formed by using a double-pulse width laser to scan twice along a preset path to form a modified layer on the (111) crystal plane and then peeling it off. Therefore, it has the beneficial effects brought by the method of obtaining a (111) plane chip in a single crystal diamond using a double-pulse width laser in the above-mentioned embodiment, which will not be repeated here.

[0073] In addition, an embodiment of the present invention also provides a system for obtaining a single-crystal diamond (111) surface wafer using a dual-pulse width laser, which is used to implement the method of the above embodiment, including a femtosecond laser source and a femtosecond laser source moving device for fixing and moving the femtosecond laser source, a picosecond laser source and a picosecond laser source moving device for fixing and moving the picosecond laser source, a diamond fixing device for fixing diamond, and a stripping device for stripping the diamond after laser cutting processing.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for obtaining a single crystal diamond (111) surface wafer using a double pulse width laser, characterized in that: The steps include: Provide (001) CVD bulk single crystal diamond with a thickness of not less than 5mm; The block-shaped single crystal diamond is processed and peeled off by using a femtosecond laser and a picosecond laser to obtain a first (111) crystal plane, and then the remaining block-shaped single crystal diamond is processed and peeled off by using a femtosecond laser and a picosecond laser to obtain a single crystal diamond (111) plane wafer; The process of using femtosecond laser and picosecond laser for processing and peeling to obtain the (111) crystal plane is as follows: first, a femtosecond laser is passed through the (001) crystal plane of the block single crystal diamond to scan and process a plurality of parallel graphitization modification lines that are distributed throughout the (111) crystal plane, and the graphitization modification lines are parallel to the diagonal [-110] crystal direction of the (001) crystal plane; then a picosecond laser is used to scan and process along the graphitization modification lines to form a leaping crack on the basis of the graphitization modification lines of the (111) crystal plane; and then peeling is performed.

2. The method according to claim 1, characterized in that: The process of using femtosecond laser and picosecond laser for processing and peeling to obtain (111) crystal plane is as follows: passing the femtosecond laser through the (001) crystal plane of the block single crystal diamond, and aligning its focus to a preset depth of the (111) crystal plane inside the block single crystal diamond; scanning and processing the laser beam of the femtosecond laser in a line scanning manner, with the crystal direction [-110] parallel to the diagonal line of the (001) crystal plane as a first preset path, so that a first graphitization modification line is formed inside the block single crystal diamond; then, by gradually reducing the focus depth of the laser beam of the femtosecond laser, scanning and processing the laser beam of the femtosecond laser in parallel to the first preset path, so that a plurality of graphitization modification lines parallel to the first graphitization modification line are formed inside the block single crystal diamond, until the graphitization modification lines cover the entire (111) crystal plane; Picosecond laser is used to scan along the graphitization modification line, so that a leaping crack is formed on the basis of the graphitization modification line of the (111) crystal plane.

3. The method according to claim 1, characterized in that: The femtosecond laser is perpendicular to the (001) crystal plane of the diamond peeling block.

4. The method according to claim 1, characterized in that: The number of the graphitization modification lines is 4 to 10, and the distances between adjacent graphitization modification lines are equal.

5. The method according to claim 1, characterized in that: The (001) crystal plane of the blocky single crystal diamond is a polished surface.

6. The method according to claim 1, characterized in that: After processing a graphitization modification line, the laser beam After the crystal rises, the next graphitization modification line is processed.

7. The method according to claim 1, characterized in that: When stripping the single crystal diamond, the single crystal diamonds on both sides of the crossing crack are stripped by a method of applying glue combined with external force separation.

8. The method according to claim 1, characterized in that: After stripping, the stripped surface of the diamond is cleaned.

9. The method according to claim 1, characterized in that: The surface area of ​​the obtained block single crystal diamond (111) crystal plane is equal to the vertical cross-sectional area of ​​the set block single crystal diamond corresponding to the scanning path.

10. A system for obtaining single crystal diamond (111) surface wafers using a dual pulse width laser, characterized in that: The method for implementing any one of claims 1 to 9 comprises: A femtosecond laser source, used for generating femtosecond laser; A femtosecond laser source moving device, used to fix the femtosecond laser source and control the femtosecond laser source to move along a set path; Picosecond laser source, used to generate femtosecond laser; A picosecond laser source moving device, used to fix the picosecond laser source and control the picosecond laser source to move along a set path; A diamond fixing device, used for fixing diamond; The stripping device is used to strip the diamond after laser cutting.

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