Method for determining crystal orientation of 3C-SiC crystal and method for determining marking direction of 3C-SiC wafer or 3C-SiC film
Through the testing and scanning technology of X-ray diffractometer, the characteristic crystal direction of 3C-SiC materials was determined and marked, which solved the uncertainty of the marking direction of 3C-SiC materials, and improved the processing accuracy and efficiency of the materials.
Patent Information
- Application Number
- CN202411193290.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-28
- Publication Date
- 2024-12-10
AI Technical Summary
The lack of methods for determining the crystal direction of 3C-SiC crystals, wafers or thin films and methods for marking directions leads to uncertainty and inefficiency in the subsequent processing of materials.
X-ray diffractometer is used to perform diffraction testing on the (113) crystal surface of 3C-SiC crystal or wafer/thin film. By adjusting the incident angle and exit angle, combining Phi scan and Chi scan, the characteristic crystal direction is determined and diffraction is at the strongest Mark the peaks to determine the marking direction.
The standard accuracy and marking efficiency of 3C-SiC materials are improved, the accuracy of subsequent processing is ensured, and the flat grinding angle error is reduced through the double judgment method and the crystal direction consistency is improved.
Smart Images
Figure CN119104579A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to a method for determining a 3C-SiC crystal orientation and a method for determining a marking direction of a 3C-SiC wafer or a 3C-SiC film, belonging to the technical field of 3C-SiC material marking. Background Art
[0002] At present, it has been found that silicon carbide crystals have more than 200 crystal forms, and they show rich physical properties due to their different structures. The most common type of silicon carbide on the market is 4H / 6H type, which is a hexagonal structure material, mainly grown by physical vapor deposition. Hexagonal silicon carbide has excellent mechanical, thermal and electrical properties. In recent years, 3C-SiC crystals have been grown by liquid phase method. The crystal structure of 3C-SiC is a cubic structure, which theoretically has the highest electron drift velocity and is more suitable for photonic devices and biomedical devices.
[0003] 4H-SiC is a hexagonal structure, and the characteristic crystal directions on the 0001 plane are [1-100] and [11-20], respectively. Different crystal directions have different physical properties. For 4H-SiC wafers, the [1-100] crystal direction will be marked to calibrate the characteristic crystal direction. The growth surface of the 3C-SiC substrate is the 111 plane, and its characteristic direction is different from that of 4H-SiC. Therefore, since 3C-SiC has a different crystal structure from 4H-SiC, it does not have the same characteristic crystal direction as 4H-SiC, so the marking method cannot be applied. In addition, since the growth thickness of 3C-SiC crystal rods cannot be as thick as 4H-SiC, each rod is more than 10mm. Some 3C-SiC crystal rods are less than 3mm thick, so it is difficult to use an orientation instrument to test the crystal direction of its side to determine the marking direction.
[0004] Therefore, the determination of the crystal orientation of 3C-SiC materials is a problem that needs to be solved. The determination of the crystal orientation affects the marking method and marking direction of subsequent materials. Therefore, there is a lack of a method for determining the crystal orientation of 3C-SiC crystals, and there is also a lack of a method for determining the marking direction of 3C-SiC wafers or 3C-SiC films and corresponding marking solutions. Summary of the invention
[0005] In order to solve the above problems, a method for determining the crystal orientation of a 3C-SiC crystal is provided. The method uses an X-ray diffractometer to determine the [11-2] crystal orientation of the 3C-SiC crystal, and then marks it, which is convenient for subsequent orientation and smooth marking of the crystal, and provides a basis for the smooth marking of 3C-SiC. A method for determining the marking direction of a 3C-SiC wafer or a 3C-SiC film is also provided. The X-ray diffractometer is used to perform Phi scanning and Chi scanning on the 3C-SiC wafer or the 3C-SiC film to determine its marking direction, thereby improving the marking accuracy and marking efficiency of the 3C-SiC wafer or the 3C-SiC film.
[0006] According to one aspect of the present application, a method for determining the crystal orientation of a 3C-SiC crystal is provided, comprising the following steps:
[0007] (1) The 3C-SiC crystal is flat-ground and placed on the sample stage of an X-ray diffractometer;
[0008] (2) Use X-rays to perform diffraction tests on the (113) crystal plane of the 3C-SiC crystal, adjust the incident angle and the exit angle of the X-rays, and record the incident angle of the strongest diffraction peak;
[0009] (3) If the incident angle of the strongest diffraction peak is not within the range of 6.36°±0.2°, repeat steps (1) and (2) until the incident angle of the strongest diffraction peak is within the range of 6.36°±0.2°;
[0010] (4) inputting the incident angle and the exit angle of the strongest diffraction peak determined in steps (2) and (3), performing a Phi scan on the (113) crystal plane, and recording the angle at the strongest diffraction peak;
[0011] (5) Then, perform Chi scanning. If the Chi scanning angle is not within ±0.5°, repeat the above steps (1) to (4) until the Chi scanning angle is within ±0.5°. Then stop scanning and make a mark to indicate the crystal orientation of the 3C-SiC crystal.
[0012] The method is tested based on the (113) crystal plane of the 3C-SiC crystal, and can quickly determine the marking direction of the wafer after the 3C-SiC crystal is cut and the [11-2] crystal direction of the 3C-SiC crystal. The angle recorded as the strongest diffraction peak in step (4) is the angle at which the marking direction is determined.
[0013] The specific operation of marking in step (5) is: draw a marking line in the radial direction along the angle of the strongest diffraction peak in step (4), and make a positioning edge mark at the edge here. The direction of the marking line is the [11-2] crystal direction of the 3C-SiC crystal.
[0014] It can be understood by those skilled in the art that the marking lines used in the above marking can be erased after the subsequent operation is completed, and the marking of the positioning edge is also a commonly used marking method in the industry, and will not cause adverse restrictions on the crystal and the wafer formed by crystal cutting. In addition, the above marking method is only an example, and those skilled in the art can also choose a suitable marking method according to actual needs, such as using a line drawing method to replace the positioning edge mark.
[0015] And the method firstly compares the incident angle at which the strongest diffraction peak determined in step (2) appears with the range of 6.36°±0.2°, and can initially determine whether there is an error in the flat grinding angle of the 3C-SiC crystal. If the incident angle at which the strongest diffraction peak determined in step (2) appears is not within the range of 6.36°±0.2°, it proves that there is an error in the flat grinding angle, and it needs to be reworked for flat grinding correction; then, the angle range of the Chi scan is used to again determine whether there is an error in the flat grinding angle of the 3C-SiC crystal. If the angle is not within ±0.5°, it proves that there is an error in the flat grinding angle, and it needs to be reworked for flat grinding correction. The present application adopts a two-time determination method to enable the orthogonal orientation deviation to be less than 0.5°, which is beneficial to the crystal orientation consistency of subsequent cutting.
[0016] Therefore, the method of the present application can not only determine the marking direction of the wafer after 3C-SiC crystal cutting and clarify the characteristic [11-2] crystal orientation of the 3C-SiC crystal, but also play a feedback role in the flat grinding process.
[0017] Optionally, the specific method of adjusting the incident angle and the exit angle of the X-ray in step (2) is:
[0018] First, determine that the exit angle is 35.87°, and scan the incident angle within the range of 6.36°±2.5° to determine the first angle of the incident angle. Then, while keeping the first angle of the incident angle unchanged, scan the exit angle within the range of 35.87°±2.5° to determine the exit angle of the strongest diffraction peak. Finally, under the determined exit angle of the strongest diffraction peak, scan the incident angle again within the range of 6.36°±2.5° to record the incident angle and exit angle at the strongest diffraction peak.
[0019] Preferably, in step (3), if the incident angle of the strongest diffraction peak is not within the range of 6.36°±0.1°, steps (1) and (2) are repeated until the incident angle of the strongest diffraction peak is within the range of 6.36°±0.1°.
[0020] The closer the incident angle of the strongest diffraction peak recorded in step (2) is to 6.36°, the more accurate the marking direction is.
[0021] Optionally, the TTV of the 3C-SiC crystal after flat grinding is less than 20 μm.
[0022] Optionally, the scanning range of the Phi scan is 0 to 360°, the scanning step length of the Phi scan is 1° / s, and the scanning range of the Chi scan is -1° to 1°, and the scanning step length is 0.1° / s.
[0023] Optionally, the thickness of the 3C-SiC crystal is less than 10 mm;
[0024] Preferably, the thickness of the 3C-SiC crystal is less than 3 mm.
[0025] Optionally, after the 3C-SiC crystal is flat-ground, the step of cleaning the surface of the crystal with a cleaning liquid is also included;
[0026] Preferably, the cleaning solution is a 10% hydrochloric acid solution.
[0027] According to another aspect of the present application, a marking method for a 3C-SiC wafer is provided. After marking using any of the above methods for determining the crystal orientation of a 3C-SiC crystal, the 3C-SiC crystal is cut to obtain a wafer, and the wafer is laser marked according to the determined crystal orientation.
[0028] According to another aspect of the present application, a method for determining a marking direction of a 3C-SiC wafer or a 3C-SiC film is provided, comprising the following steps:
[0029] (1) polishing a 3C-SiC wafer or a 3C-SiC film and placing it on a sample stage of an X-ray diffractometer;
[0030] (2) using X-rays to perform a diffraction test on the (113) crystal plane of a 3C-SiC wafer or 3C-SiC film, adjusting the incident angle and the exit angle of the X-rays, and recording the incident angle of the strongest diffraction peak;
[0031] (3) If the incident angle of the strongest diffraction peak is not within the range of 6.36°±0.2°, repeat steps (1) and (2) until the incident angle of the strongest diffraction peak is within the range of 6.36°±0.2°;
[0032] (4) inputting the incident angle and the exit angle of the strongest diffraction peak determined in steps (2) and (3), performing a Phi scan on the (113) crystal plane, and recording the angle at the strongest diffraction peak;
[0033] (5) Then, Chi scanning is performed. If the Chi scanning angle is not within ±0.2°, the above steps (1) to (4) are repeated until the Chi scanning angle is within ±0.2°. The scanning is stopped and a mark is made to indicate the marking direction of the 3C-SiC wafer or 3C-SiC film.
[0034] In the above-mentioned polishing process of the 3C-SiC wafer or 3C-SiC film, the polishing material is zirconium oxide and silicon dioxide with a weight ratio of 1:5, and the thickness removed each time is 0.5 μm.
[0035] Optionally, the specific method of adjusting the incident angle and the exit angle of the X-ray in step (2) is:
[0036] First, determine that the exit angle is 35.87°, and scan the incident angle within the range of 6.36°±2.5° to determine the first angle of the incident angle. Then, while keeping the first angle of the incident angle unchanged, scan the exit angle within the range of 35.87°±2.5° to determine the exit angle of the strongest diffraction peak. Finally, under the determined exit angle of the strongest diffraction peak, scan the incident angle again within the range of 6.36°±2.5° to record the incident angle and exit angle at the strongest diffraction peak.
[0037] Optionally, the scanning range of the Phi scan is 0 to 360°, and the scanning step is 1° / s.
[0038] Optionally, the scanning range of the Chi scan is -0.5° to 0.5°, and the scanning step is 0.05° / s.
[0039] Optionally, the 3C-SiC film has a thickness of 10-50 μm, preferably 30-50 μm.
[0040] The 3C-SiC film refers to a 3C-SiC epitaxial layer, that is, an epitaxial 3C-SiC material obtained by epitaxial growth on a 4H-SiC or other crystalline SiC substrate.
[0041] Based on the same principle as determining the crystal orientation of a 3C-SiC crystal, testing with the (113) crystal plane of a 3C-SiC wafer or 3C-SiC film as a reference can quickly determine the marking direction of the 3C-SiC wafer or 3C-SiC film. The operator can quickly identify the marking direction of the 3C-SiC material based on the markings made, thereby improving the marking accuracy and efficiency of the 3C-SiC wafer or 3C-SiC film and providing an indication for the subsequent processing of the 3C-SiC wafer or 3C-SiC film.
[0042] The specific operation of marking in step (5) is: draw a marking line in the radial direction at the angle of the strongest diffraction peak in step (4). The marking line can characterize the characteristic [11-2] crystal orientation of the 3C-SiC wafer or 3C-SiC film. The direction of the marking line is the [11-2] crystal orientation of the 3C-SiC wafer or 3C-SiC film. After marking, it is convenient for operators to quickly distinguish the crystal orientation of the 3C-SiC wafer or 3C-SiC film. In order not to affect the delivery and use of the wafer, the marking line can be erased after marking is completed.
[0043] By using any of the above methods for determining the marking direction of a 3C-SiC wafer or a 3C-SiC film, after determining the marking direction of the 3C-SiC wafer or the 3C-SiC film, laser marking can be directly used. The center line of at least one marking mark formed after marking along the radial direction of the wafer or film is the [11-2] crystal direction of the 3C-SiC wafer or film.
[0044] The beneficial effects of this application include but are not limited to:
[0045] 1. The method for determining the crystal orientation of a 3C-SiC crystal of the present application uses X-rays to perform a diffraction test on the (113) crystal plane of the 3C-SiC crystal, which can determine the crystal orientation of the 3C-SiC crystal, and the positioning edge marks made on the crystal can also provide instructions for the marking direction of the wafer formed after the crystal is cut, so that the operator can quickly identify the marking direction of the 3C-SiC material according to the marks made, thereby improving the marking accuracy and marking efficiency of the 3C-SiC crystal and providing an indication for the subsequent processing of the 3C-SiC crystal.
[0046] 2. The method for determining the crystal orientation of a 3C-SiC crystal of the present application, in which a radial marking line and a positioning edge marking are performed at the strongest diffraction peak in step (4), can characterize the characteristic [11-2] crystal orientation of the 3C-SiC crystal. The direction of the marking line is the [11-2] crystal orientation direction of the 3C-SiC crystal, which facilitates the operator to quickly distinguish the crystal orientation of the 3C-SiC crystal.
[0047] 3. The method for determining the crystal orientation of a 3C-SiC crystal of the present application, by comparing the incident angle at which the strongest diffraction peak determined in step (2) appears with the range of 6.36°±0.2° and whether the Chi scanning angle in step (5) is within the range of ±0.5°, double determines whether there is an error in the flat grinding angle of the 3C-SiC crystal, thereby providing feedback for the flat grinding process, and can also reduce the deviation from the orthogonal orientation, which is beneficial to the consistency of the crystal orientation of subsequent cutting. BRIEF DESCRIPTION OF THE DRAWINGS
[0048] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:
[0049] Figure 1 This is a test schematic diagram of different incident angles and diffraction intensities involved in Example 1 of the present application.
[0050] Figure 2 This is the test image of the Phi scan involved in Example 1 of the present application.
[0051] Figure 3 This is the test diagram of the Chi scan involved in Example 1 of the present application.
[0052] Figure 4 This is the position of the marking line in the 3C-SiC crystal involved in Example 1 of the present application.
[0053] List of parts and reference numerals:
[0054] 1. 3C-SiC crystal; 2. Marking line; 3. Positioning edge. DETAILED DESCRIPTION
[0055] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.
[0056] Unless otherwise specified, the raw materials in the examples and comparative examples of the present application were purchased through commercial channels.
[0057] Unless otherwise specified, the methods used in the examples and comparative examples of the present application are conventional methods in the prior art.
[0058] Example 1
[0059] This embodiment relates to a method for determining the crystal orientation of a 3C-SiC crystal, comprising the following steps:
[0060] (1)Reference Figure 4 (a) The grown 3C-SiC crystal 1 is flat-ground until the TTV is less than 20 μm, then cleaned with a 10% hydrochloric acid solution, and then the 3C-SiC crystal 1 is placed on the sample stage of an X-ray diffractometer;
[0061] (2) X-ray diffraction test was performed on the (113) crystal plane of 3C-SiC crystal 1. First, the incident angle was scanned within the range of 6.36°±2.5° when the exit angle was 35.87° to determine the first angle of the incident angle. Then, the exit angle was scanned within the range of 35.87°±2.5° while the first angle of the incident angle remained unchanged to determine the exit angle of the strongest diffraction peak. Finally, the reference Figure 1 , under the determined exit angle of the strongest diffraction peak, the incident angle is scanned again in the range of 6.36°±2.5°, and the incident angle and exit angle at the strongest diffraction peak are recorded;
[0062] (3) If the incident angle of the strongest diffraction peak determined in step (2) is not within the range of 6.36°±0.2°, repeat steps (1) and (2) until the incident angle of the strongest diffraction peak is within the range of 6.36°±0.2°;
[0063] (4) Input the incident angle and the exit angle of the strongest diffraction peak determined in steps (2) and (3), and perform a Phi scan on the (113) crystal plane. The scanning range of the Phi scan is 0 to 360°, and the scanning step is 1° / s. The Phi scan test chart is referenced Figure 2 , record the angle of the strongest diffraction peak;
[0064] (5) Then perform Chi scanning. The scanning range of Chi scanning is -1° to 1°, and the scanning step is 0.1° / s. If the Chi scanning angle is not within ±0.5°, repeat the above steps (1) to (4) until the Chi scanning angle is within ±0.5°. The Chi scanning test chart is referenced Figure 3 , stop scanning, draw a radial marking line 2 along the angle of the strongest diffraction peak in step (4), and mark the positioning edge 3 at the edge here. The position of the marking line 2 and the positioning edge 3 is referenced to Figure 4 (b) is used to indicate the crystal orientation of the 3C-SiC crystal and the marking direction of the wafer obtained after the crystal is cut.
[0065] The above-mentioned marking line 2 is the [11-2] crystal direction of the 3C-SiC crystal 1. In the actual application of the 3C-SiC crystal 1, refer to Figure 4 (c) Cut the 3C-SiC crystal 1 with the marking line 2 and the positioning edge 3 to obtain a 3C-SiC wafer. The positioning edge mark can help the operator to quickly identify it, and then the wafer can be marked with a laser.
[0066] The marking direction can be referred to Figure 4 In the direction of the two lines in (c), the crystal number is marked on the groove parallel to the positioning edge on the surface of the wafer, and the wafer number of the wafer is marked in the direction of 30° to the positioning edge groove. The distance between the above crystal number and wafer number marking and the edge of the wafer is greater than 1mm, and the center line of the crystal number along the radial direction of the wafer is the [11-2] crystal direction of the 3C-SiC wafer. When the wafer marked with the crystal number and wafer number is used in subsequent applications, the operator can directly distinguish the [11-2] crystal direction of the wafer, and can quickly find the position at 30° to the [11-2] crystal direction, which is convenient for other operations. Figure 4 (c) The two lines are only for reference and do not actually exist. Marking is performed in the direction of the two lines to form corresponding marking marks.
[0067] Since the 3C-SiC crystal 1 is also marked with a marking line 2, the marking line 2 only exists in the topmost wafer of the 3C-SiC crystal 1 as the 3C-SiC crystal 1 is cut. The marking mark of the crystal number formed by the wafer with the marking line also coincides with the marking line along the center line of the radial direction of the wafer. When the wafer is used, the marking line can be erased.
[0068] Example 2
[0069] This embodiment relates to a method for determining a marking direction of a 3C-SiC wafer, comprising the following steps:
[0070] (1) Polishing the 3C-SiC wafer and placing it on the sample stage of an X-ray diffractometer;
[0071] (2) using X-rays to perform a diffraction test on the (113) crystal plane of the 3C-SiC wafer, first determining that the incident angle is 35.87°, scanning the incident angle within the range of 6.36°±2.5°, and determining a first angle of the incident angle, then scanning the incident angle within the range of 35.87°±2.5° while keeping the first angle of the incident angle unchanged, and determining the incident angle of the strongest diffraction peak; finally, at the determined incident angle of the strongest diffraction peak, scanning the incident angle within the range of 6.36°±2.5°, and recording the incident angle and the exit angle at the strongest diffraction peak;
[0072] (3) If the incident angle of the strongest diffraction peak determined in step (2) is not within the range of 6.36°±0.2°, repeat steps (1) and (2) until the incident angle of the strongest diffraction peak is within the range of 6.36°±0.2°;
[0073] (4) Input the incident angle and the exit angle of the strongest diffraction peak determined in steps (2) and (3), perform a Phi scan on the (113) crystal plane, the scanning range of the Phi scan is 0 to 360°, the scanning step length is 1° / s, and record the angle of the strongest diffraction peak;
[0074] (5) Then, Chi scanning is performed. The scanning range of Chi scanning is -0.5° to 0.5°, and the scanning step length is 0.05° / s. If the Chi scanning angle is not within ±0.2°, the above steps (1) to (4) are repeated until the Chi scanning angle is within ±0.2°. The scanning is stopped, and a marking line is drawn in the radial direction along the angle of the strongest diffraction peak in step (4). The direction of the marking line is the direction of the [11-2] crystal orientation of the 3C-SiC wafer, indicating the marking direction of the 3C-SiC wafer. Then, laser marking can be performed directly according to the determined marking direction [11-2]. The laser marking method is the same as that in Example 1.
[0075] Example 3
[0076] This embodiment relates to a method for determining a marking direction of a 3C-SiC film, comprising the following steps:
[0077] (1) Polishing the 3C-SiC film and placing it on the sample stage of an X-ray diffractometer;
[0078] (2) using X-rays to perform a diffraction test on the (113) crystal plane of the 3C-SiC film, first determining that the incident angle is 35.87°, scanning the incident angle within the range of 6.36°±2.5°, and determining a first angle of the incident angle, then scanning the incident angle within the range of 35.87°±2.5° while keeping the first angle of the incident angle unchanged, and determining the incident angle of the strongest diffraction peak; finally, at the determined incident angle of the strongest diffraction peak, scanning the incident angle within the range of 6.36°±2.5°, and recording the incident angle and the incident angle at the strongest diffraction peak;
[0079] (3) If the incident angle of the strongest diffraction peak determined in step (2) is not within the range of 6.36°±0.2°, repeat steps (1) and (2) until the incident angle of the strongest diffraction peak is within the range of 6.36°±0.2°;
[0080] (4) Input the incident angle and the exit angle of the strongest diffraction peak determined in steps (2) and (3), perform a Phi scan on the (113) crystal plane, the scanning range of the Phi scan is 0 to 360°, the scanning step length is 1° / s, and record the angle of the strongest diffraction peak;
[0081] (5) Then, Chi scanning is performed, and the scanning range of Chi scanning is -0.5° to 0.5°. If the Chi scanning angle is not within ±0.2°, the above steps (1) to (4) are repeated until the Chi scanning angle is within ±0.2°. The scanning is stopped, and a marking line is drawn in the radial direction along the angle of the strongest diffraction peak in step (4). The direction of the marking line is the direction of the [11-2] crystal orientation of the 3C-SiC wafer, indicating the marking direction [11-2] of the 3C-SiC film. After that, laser marking can be performed directly according to the determined marking direction. The laser marking method is the same as that in Example 1.
[0082] The above is only the embodiment of the present application, and the protection scope of the present application is not limited by these specific embodiments, but is determined by the claims of the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the technical ideas and principles of the present application should be included in the protection scope of the present application.
Claims
1. A method for determining the crystal orientation of a 3C-SiC crystal, characterized in that: The steps include: (1) The 3C-SiC crystal is flat-ground and placed on the sample stage of an X-ray diffractometer; (2) Use X-rays to perform diffraction tests on the (113) crystal plane of the 3C-SiC crystal, adjust the incident angle and the exit angle of the X-rays, and record the incident angle of the strongest diffraction peak; (3) If the incident angle of the strongest diffraction peak is not within the range of 6.36°±0.2°, repeat steps (1) and (2) until the incident angle of the strongest diffraction peak is within the range of 6.36°±0.2°; (4) inputting the incident angle and the exit angle of the strongest diffraction peak determined in steps (2) and (3), performing a Phi scan on the (113) crystal plane, and recording the angle at the strongest diffraction peak; (5) Then, perform Chi scanning. If the Chi scanning angle is not within ±0.5°, repeat the above steps (1) to (4) until the Chi scanning angle is within ±0.5°. Then stop scanning and make a mark to indicate the crystal orientation of the 3C-SiC crystal.
2. The method according to claim 1, characterized in that The specific method for adjusting the incident angle and the outgoing angle of the X-ray in step (2) is: First, determine that the exit angle is 35.87°, and scan the incident angle within the range of 6.36°±2.5° to determine the first angle of the incident angle. Then, while keeping the first angle of the incident angle unchanged, scan the exit angle within the range of 35.87°±2.5° to determine the exit angle of the strongest diffraction peak. Finally, under the determined exit angle of the strongest diffraction peak, scan the incident angle again within the range of 6.36°±2.5° to record the incident angle and exit angle at the strongest diffraction peak.
3. The method according to claim 1, characterized in that The TTV of 3C-SiC crystal after flat grinding is less than 20μm.
4. The method according to claim 1, characterized in that The scanning range of the Phi scan is 0-360°, and the scanning step is 1° / s; and / or The scanning range of the Chi scan is -1° to 1°, and the scanning step is 0.1° / s.
5. The method according to claim 1, characterized in that The thickness of the 3C-SiC crystal is less than 10 mm; Preferably, the thickness of the 3C-SiC crystal is less than 3 mm.
6. The method according to claim 1, characterized in that After the 3C-SiC crystal is flat-ground, the step of using a cleaning liquid to clean the surface of the crystal is also included; Preferably, the cleaning solution is a 10% hydrochloric acid solution.
7. A method for determining the marking direction of a 3C-SiC wafer or a 3C-SiC film, characterized in that: The steps include: (1) polishing a 3C-SiC wafer or a 3C-SiC film and placing it on a sample stage of an X-ray diffractometer; (2) using X-rays to perform a diffraction test on the (113) crystal plane of a 3C-SiC wafer or 3C-SiC film, adjusting the incident angle and the exit angle of the X-rays, and recording the incident angle of the strongest diffraction peak; (3) If the incident angle of the strongest diffraction peak is not within the range of 6.36°±0.2°, repeat steps (1) and (2) until the incident angle of the strongest diffraction peak is within the range of 6.36°±0.2°; (4) inputting the incident angle and the exit angle of the strongest diffraction peak determined in steps (2) and (3), performing a Phi scan on the (113) crystal plane, and recording the angle at the strongest diffraction peak; (5) Then, Chi scanning is performed. If the Chi scanning angle is not within ±0.2°, the above steps (1) to (4) are repeated until the Chi scanning angle is within ±0.2°. Then, the scanning is stopped and a mark is made to indicate the marking direction of the 3C-SiC wafer or 3C-SiC film.
8. The method according to claim 7, characterized in that The specific method for adjusting the incident angle and the outgoing angle of the X-ray in step (2) is: First, determine that the exit angle is 35.87°, and scan the incident angle within the range of 6.36°±2.5° to determine the first angle of the incident angle. Then, while keeping the first angle of the incident angle unchanged, scan the exit angle within the range of 35.87°±2.5° to determine the exit angle of the strongest diffraction peak. Finally, under the determined exit angle of the strongest diffraction peak, scan the incident angle again within the range of 6.36°±2.5° to record the incident angle and exit angle at the strongest diffraction peak.
9. The method according to claim 7, characterized in that: The scanning range of the Phi scan is 0-360°, and the scanning step is 0.5° / s.
10. The method according to claim 7, characterized in that The scanning range of the Chi scan is -0.5° to 0.5°, and the scanning step is 0.05° / s.