A method for determining crystal form of a silicon carbide single crystal polymorphic coexisting region and application thereof

Abstract

The application discloses a crystal type determination method for a polymorph coexisting region of a silicon carbide single crystal and application, and belongs to the technical field of silicon carbide material detection. The determination method comprises the following steps: (1) testing: performing Raman testing on the silicon carbide single crystal to obtain a test spectrum, and classifying characteristic peaks in the test spectrum into first crystal type Raman characteristic peaks and second crystal type Raman characteristic peaks according to Raman characteristic peaks of different crystal types; (2) determining: determining, according to a peak intensity ratio of the first crystal type Raman characteristic peak and the second crystal type Raman characteristic peak, whether the crystal type at the test point is the first crystal type, a coexisting crystal type of the first crystal type and the second crystal type or the second crystal type. The method adopts Raman to test the silicon carbide single crystal material, and determines the crystal type at the test point according to a test spectrum, can accurately distinguish and quantitatively characterize the crystal type of the polymorph coexisting region of the silicon carbide single crystal material, and can be used for large-scale detection of the silicon carbide single crystal rod.

Description

TECHNICAL FIELD

[0001] The application relates to a crystal type determination method for a silicon carbide single crystal polymorph coexisting region and application, and belongs to the technical field of silicon carbide material detection. BACKGROUND

[0002] There are more than 200 homopolymer types of SiC single crystals. Since the growth temperature and pressure intervals of different crystal types intersect and the stacking fault energies of different polymorphs are close, polymorph coexistence is prone to occur during SiC single crystal growth using the PVT method, especially at the edges of a silicon carbide single crystal rod. In order to facilitate the optimization of the production process and the subsequent processing and production, it is often necessary to detect the produced silicon carbide single crystal material to determine the crystal type of the material.

[0003] The existing test equipment is mainly used for distinguishing by normal light or polarized light irradiation. When normal light irradiates the conductive silicon carbide crystal rod, different colors are presented due to different doping concentrations of N elements, which can realize the distinction of the polymorph of the conductive silicon carbide crystal rod to a certain extent. However, for semi-insulating silicon carbide, normal light cannot distinguish the polymorph. The polarized light irradiation method is mainly used for the detection of silicon carbide substrates. After the silicon carbide single crystal rod is processed by flat grinding and rounding, the edge roughness changes, so that the penetration depth of the polarized light source on the carbon surface and the silicon surface is shallow, and it is difficult to accurately determine the distribution position of the polymorph of the crystal rod sidewall. In addition, as the size of the silicon carbide crystal rod gradually increases and the thickness gradually thickens, it is more difficult to judge the polymorph by the above two methods, and it is difficult to accurately distinguish the polymorph coexisting position. The above two methods are difficult to accurately determine the crystal type of the polymorph coexisting region of the silicon carbide single crystal rod sidewall.

[0004] At present, XRD can be used for polymorph detection of silicon carbide single crystal rods. However, when the XRD detects the polymorph coexisting region, it is difficult to distinguish which crystal type is the main one in the polymorph coexisting region due to the relatively large detection spot coverage area, so the detection accuracy is low. In addition, the crystal needs to be erected and fixed during the XRD detection of the silicon carbide single crystal rod, and the position of the crystal needs to be adjusted again for each detection position. In addition, the XRD itself needs to adjust the angle of the X-ray before testing, which makes the detection time of the XRD very long, and it is difficult to realize the large-scale detection of the silicon carbide crystal rod. SUMMARY

[0005] In order to solve the above problems, a crystal type determination method for a silicon carbide single crystal polymorph coexisting region and application are provided. The method uses Raman to test the silicon carbide single crystal material and determines the crystal type at the test point according to the test spectrum, can accurately distinguish and quantitatively characterize the crystal type of the polymorph coexisting region of the silicon carbide single crystal material, and can be used for large-scale detection of the silicon carbide single crystal rod.

[0006] According to one aspect of the present application, a method for determining the crystal form of a silicon carbide single crystal polymorphic coexisting region is provided, comprising the following steps:

[0007] (1) Testing: Raman testing is performed on the silicon carbide single crystal to obtain a test spectrum, and the characteristic peaks in the test spectrum are classified into first crystal form Raman characteristic peaks and second crystal form Raman characteristic peaks according to the Raman characteristic peaks of different crystal forms;

[0008] (2) Determining: if RPS1 / RPS2≥10 and 0.5≤RPS2 / I Baseline ≤5, then the crystal form at the test point is the first crystal form; if 0.1≤RPS1 / RPS2<10 and RPS1 / I Baseline ≥2, RPS2 / I Baseline ≥2, then the crystal form at the test point is the coexisting crystal form of the first crystal form and the second crystal form; if RPS1 / RPS2<0.1 and 0.5≤RPS1 / I Baseline ≤5, then the crystal form at the test point is the second crystal form, wherein RPS1 is the peak intensity of the first crystal form Raman characteristic peak, RPS2 is the peak intensity of the second crystal form Raman characteristic peak, and I Baseline is the baseline peak intensity.

[0009] The determining basis of step (2) is the ratio of the peak intensity of the first crystal form Raman characteristic peak to the peak intensity of the second crystal form Raman characteristic peak and the ratio of the peak intensity of the Raman characteristic peak to the baseline peak intensity. This basis is that the Raman activity of different polytypes is different, which is reflected in the difference in peak intensity on the Raman spectrum. In SiC, the Raman characteristic peaks of different crystal forms represent the existence of polytypes, and the peak intensity reflects the relative content of polytypes. By the ratio of the peak intensity of different crystal form characteristic peaks, the type and coexisting ratio of polytypes can be determined, so it is more in line with the characteristics of Raman detection of silicon carbide single crystal material, the determination result is more accurate, and the detection precision and accuracy of silicon carbide single crystal material are improved.

[0010] In addition to the ratio of the peak intensity of the Raman characteristic peak of the first crystal form and the second crystal form in the above determining condition, the ratio of the peak intensity of the Raman characteristic peak to the baseline peak intensity is also introduced. This ratio is used to determine the peak intensity of the weaker Raman characteristic peak. If it is not within the above range, it represents that the Raman characteristic peak is relatively weak, and the accuracy of peak searching and fitting is also relatively weak. Therefore, this point is considered as an interference peak, which is a noise signal, and it is unnecessary to calculate and count. Therefore, the determination condition of the ratio of the Raman characteristic peaks of two crystal forms and the ratio of the peak intensity of the Raman characteristic peak to the baseline peak intensity can improve the accuracy of the determination method of the present application.

[0011] Optionally, the first crystal form is one of a 4H crystal form, a 6H crystal form, or a 15R crystal form, and the second crystal form is one of a 4H crystal form, a 6H crystal form, or a 15R crystal form.

[0012] Optionally, the 4H crystal form Raman characteristic peak is 776.62±1.00cm -1 , the 6H crystal form Raman characteristic peak is 788.05±1.00cm -1 , and the 15R crystal form Raman characteristic peak is 784.59±1.00cm -1 .

[0013] Optionally, the Raman test is a micro-Raman test.

[0014] Since each test point in the Raman test needs to be focused to continue testing, the test instrument first needs to determine whether it is focused. If it is not focused, the light or Raman test parameters need to be adjusted for refocusing. The micro-Raman can realize microscopic observation of the test point, improve the judgment efficiency of whether the test point is focused during detection, and further improve the detection efficiency and detection accuracy.

[0015] Optionally, the laser wavelength range of the Raman test is 325nm-785nm, preferably 532nm-785nm.

[0016] During detection, when the focal length changes, the light intensity will change. When the Raman detection mechanism is used for focusing, if there is no other light adjustment mechanism, the laser spot is adjusted to the smallest and brightest to achieve focusing. However, this focusing method has a certain focusing deviation compared to bright field focusing. When the laser wavelength is above 532nm, the focusing deviation can be ignored. Therefore, under the wavelength of 532nm-785nm, quantitative detection of multiple types can be realized without light adjustment. However, when the laser wavelength is below 532nm, the focusing deviation will cause the detection point to be in an abnormal focusing state, and the remaining light adjustment mechanism needs to be used for light adjustment to realize detection.

[0017] Optionally, the step moving speed of the Raman test is 3000μm / step-15000μm / step.

[0018] The step moving speed affects the test point density in the Mapping test process of micro-Raman, which affects the overall test efficiency on the one hand and the test accuracy of crystal form judgment and crystal form conversion on the other hand.

[0019] Optionally, the laser spot of the Raman test is 1μm-5μm.

[0020] The index can affect the judgment of test accuracy, especially in the process of polymorphism symbiosis or crystal type conversion, and the test accuracy is relatively high when the light spot is small. The light spot of the Raman test adopted by the application is micron level, and the test light spot of the XRD itself is millimeter level. Therefore, the light spot of the Raman test is smaller than the test light spot of the XRD. Although Raman and XRD can simultaneously measure multiple crystal types of the silicon carbide crystal bar, in the polymorphism symbiosis area, Raman and XRD will have multiple characteristic peaks of different crystal types in their respective spectra. Because the test light spot of XRD covers a relatively large area, it is difficult to distinguish which crystal type is the main one in the crystal type symbiosis area, so the test accuracy is low. However, the detection area of the Raman test is small, so the detection accuracy of the silicon carbide single crystal material is higher.

[0021] Optionally, the exposure time of the Raman test is 0.5s-10s.

[0022] The exposure time can affect the test efficiency on the one hand, and the longer the exposure time, the longer the single-point test time and the longer the test time. On the other hand, the exposure time affects the peak fitting accuracy and the judgment of crystal type conversion accuracy. The longer the exposure time, the stronger the peak intensity, and the higher the relative peak fitting accuracy within a certain range, and the more accurate the crystal type judgment in the polymorphism symbiosis process of crystal type conversion.

[0023] Optionally, the Z-axis automatic focusing height range of the Raman test is -100-+100μm.

[0024] Because of the height fluctuation of the side wall of the silicon carbide crystal bar, the signal strength of the optimal reaction is further improved to improve the accuracy of the detection result.

[0025] According to another aspect of the application, the application of the crystal type determination method of the polymorphism symbiotic area of the silicon carbide single crystal in the crystal type detection of the silicon carbide material is provided.

[0026] The beneficial effects of the application include but are not limited to:

[0027] 1. The crystal type determination method of the polymorphism symbiotic area of the silicon carbide single crystal, which scans the silicon carbide single crystal by Raman, and determines the crystal type according to the peak intensity ratio of the Raman characteristic peaks of the first crystal type and the second crystal type, so as to quantitatively and accurately obtain the polymorphism distribution of the silicon carbide single crystal material. The determination result is fed back to the production or processing, so as to realize the optimization of the production process and guide the adjustment of the processing process.

[0028] 2. The crystal type determination method of the polymorphism symbiotic area of the silicon carbide single crystal has the characteristics of high detection efficiency, short detection time, low detection cost and wide detection range, and can realize batch detection of the silicon carbide single crystal material and industrialized use.

[0029] 3. The method for determining the crystal form of the polymorphic coexisting region of the silicon carbide single crystal according to the present application has a wide detection range, and is not only suitable for polymorphic detection of the sidewall of a silicon carbide single crystal rod, but also can be used for polymorphic detection of a silicon carbide substrate, and realizes quantitative characterization of the silicon carbide single crystal material.

[0030] 4. The method for determining the crystal form of the polymorphic coexisting region of the silicon carbide single crystal according to the present application determines the specific crystal form type at the test point according to the ratio of the peak intensity of the Raman characteristic peaks of different crystal forms, is more in line with the characteristics of the silicon carbide single crystal material, and thus has higher detection accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0031] The accompanying drawings, which are included to provide a further understanding of the present application, form a part of the present application and illustrate the illustrative embodiments of the present application and together with the description serve to explain the present application. In the drawings:

[0032] Figure 1 For Figure 3 Raman spectra of different crystal forms of a silicon carbide crystal rod.

[0033] Figure 2 Raman spectra of the coexistence of 4H crystal form and 15R crystal form at a test point of a 4H-silicon carbide single crystal rod in Example 1 of the present application.

[0034] Figure 3 Raman spectra of the coexistence of 6H crystal form and 15R crystal form at a test point of a 4H-silicon carbide single crystal rod in Example 1 of the present application.

[0035] Figure 4 Polymorphic distribution diagram of the sidewall of a 4H-silicon carbide single crystal rod in Example 1 of the present application. DETAILED DESCRIPTION

[0036] The present application will be described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0037] The methods used in the examples of the present application are conventional methods in the prior art unless otherwise specified. In the following examples, the silicon carbide single crystal rod is subjected to Raman testing, and the basis for determining the crystal form according to the peak intensity ratio between different crystal form characteristic peaks is that Raman spectroscopy is a scattering spectrum. When a light beam is irradiated onto a substance, part of the light will be scattered. In addition to the component with the same frequency as the incident light, there are components with changed frequencies. This change includes an increase and a decrease in frequency. By analyzing the frequency and intensity of these scattered lights, the molecular vibration and rotation information of the substance can be obtained, thereby enabling the study of the structure and properties of the substance. In crystal form analysis, different crystal forms will result in different Raman characteristic peak positions, intensities and quantities due to different molecular arrangement modes and symmetry rules, thereby exhibiting different Raman characteristic peak positions. The intensity of the characteristic peak mainly reflects the degree of molecular vibration or rotation, and the intensity ratio can be used to describe the relative intensity relationship between different characteristic peaks.

[0038] Example 1

[0039] The present example relates to a method for determining the crystal form of a silicon carbide single crystal rod polymorphic intergrowth region, comprising the following steps:

[0040] (1) Testing: subjecting the silicon carbide single crystal to microscopic Raman testing to obtain a test spectrum, and classifying the characteristic peaks in the test spectrum into first crystal form Raman characteristic peaks and second crystal form Raman characteristic peaks according to the Raman characteristic peaks of different crystal forms. The wavelength of the Raman testing is 325 nm, the step movement speed is 3000 μm / step, the light spot is 1 μm, the exposure time is 0.5 s, and a light adjustment mechanism is used to assist in the precise focusing of each test point during the Raman testing.

[0041] (2) Determining: if RPS1 / RPS2>0.7, then the crystal form at the test point is the first crystal form; if 0.3≤RPS1 / RPS2≤0.7, then the crystal form at the test point is the intergrowth crystal form of the first crystal form and the second crystal form; and if RPS1 / RPS2<0.3, then the crystal form at the test point is the second crystal form. RPS1 is the peak intensity of the first crystal form Raman characteristic peak, and RPS2 is the peak intensity of the second crystal form Raman characteristic peak.

[0042] In step (2), the first crystal form is one of a 4H crystal form, a 6H crystal form or a 15R crystal form, the second crystal form is one of a 4H crystal form, a 6H crystal form or a 15R crystal form, and the crystal form types of the first crystal form and the second crystal form are different. The 4H crystal form Raman characteristic peak is 776.62±0.5 cm -1 , the 6H crystal form Raman characteristic peak is 788.05±0.5 cm -1 , and the 15R crystal form Raman characteristic peak is 784.59±0.5 cm -1 .

[0043] Figure 1 The Raman spectra of the reference peaks for silicon carbide single crystal rods in the 4H, 6H, and 15R crystal forms are provided in this application. The reference peak with the strongest intensity for each crystal form is used as the criterion for determination. Since the characteristic peaks in Raman testing are affected by substrate stress, ambient temperature and humidity, and substrate surface roughness, the characteristic peaks at the test points shift relative to the reference peaks. Therefore, in step (2), for the 4H crystal form, 776.62 ± 1.00 cm⁻¹ is used. -1 The peak at the position is used as a Raman characteristic peak; for the 6H crystal form, it is 788.05 ± 1.00 cm⁻¹. -1 The peak at the position is taken as a Raman characteristic peak, and for the 15R crystal form, it is 784.59±1.00 cm⁻¹. -1 The peak at the location is used as a Raman characteristic peak.

[0044] The method of Example 1 was used to test 4H-silicon carbide single crystal rods and 6H-silicon carbide single crystal rods respectively. Specifically, the 4H-silicon carbide single crystal rods and 6H-silicon carbide single crystal rods to be tested were placed in the test area after being flat-ground and rolled into a round shape. Then, the sidewalls were mapped and scanned according to steps (1) and (2) and each test point was judged.

[0045] Figure 2 This is the Raman spectrum of a 4H-silicon carbide single crystal rod at a test point where both the 4H and 15R crystal forms coexist. Based on... Figure 2 It can be seen that at this test point, the RPS1 / 15R of 0.1≤4H is <10, and the RPS1 / I of 4H is <10. Baseline ≥2, 15R RPS2 / I Baseline ≥2, therefore the crystal form at this test point is determined to be a co-occurrence of 4H and 15R. Figure 3 This is the Raman spectrum of a 4H-silicon carbide single crystal rod where both the 6H and 15R crystal forms coexist at a certain test point. Based on... Figure 3 It can be seen that at this test point, the RPS1 / 15R of 0.1≤6H is <10, and the RPS1 / I of 6H is <10. Baseline ≥2, 15R RPS2 / I Baseline ≥2, therefore the crystal form at this test point is determined to be a symbiotic crystal form of 6H and 15R.

[0046] After the above steps (1) and (2) for testing and determination, the polymorphic distribution of the 4H-silicon carbide single crystal rod is obtained based on the crystal form determination results at each test point. The test results are shown in […]. Figure 4 , Figure 4 The green color represents the 6H crystal form, the blue color represents the 15R crystal form, and the red color represents the 4H crystal form. Figure 4The 6H crystal form width is 19246.8 μm measured in the middle (A) figure, and the 15R crystal form width is 7727.96 μm measured in the (B) figure.

[0047] The above test results prove that the crystal form determination method of the silicon carbide single crystal in the application can realize quantitative characterization of the crystal form of the silicon carbide single crystal material.

[0048] Example 2

[0049] This example relates to a crystal form determination method of a polytype coexisting region of a silicon carbide single crystal rod, which is different from example 1 in that the wavelength of the Raman test is 532 nm, the step moving speed is 15000 μm / step, the light spot is 5 μm, the exposure time is 10 s, and a light adjusting mechanism is used for assisting in the Raman test to realize accurate focusing of each test point, and the rest are the same as example 1.

[0050] The method of this example is used to test the side walls of 4H-silicon carbide single crystal rods and 6H-silicon carbide single crystal rods respectively, and the polytype distribution of the side walls of each silicon carbide single crystal rod is obtained.

[0051] Example 3

[0052] This example is different from example 1 in that the test wavelength is 785 nm, and the rest is the same as example 1.

[0053] The method of this example is used to test the side walls of 4H-silicon carbide single crystal rods and 6H-silicon carbide single crystal rods respectively, and the polytype distribution of the side walls of each silicon carbide single crystal rod is obtained.

[0054] Example 4

[0055] This example is different from example 1 in that the micro-Raman is not used, but the ordinary Raman test is used, and the rest is the same as example 1.

[0056] The method of this example is used to test the side walls of 4H-silicon carbide single crystal rods and 6H-silicon carbide single crystal rods respectively, and the polytype distribution of the side walls of each silicon carbide single crystal rod is obtained.

[0057] Example 5

[0058] This example is different from example 1 in that the exposure time is 10 s, and the rest is the same as example 1.

[0059] The method of this example is used to test the side walls of 4H-silicon carbide single crystal rods and 6H-silicon carbide single crystal rods respectively, and the polytype distribution of the side walls of each silicon carbide single crystal rod is obtained.

[0060] Experimental Example

[0061] The sidewall polytype of each silicon carbide single crystal rod in the above examples is tested by XRD testing, and the testing method of XRD is as follows:

[0062] 1. First, the SiC sidewall crystal phase is confirmed by XRD. The atoms in the single crystal are arranged in a three-dimensional periodic manner, which can be regarded as a series of parallel planes with a crystal face spacing d. When a monochromatic X-ray with a certain energy is incident on the plane, and the optical path difference between adjacent planes is n times the wavelength (n is an integer), diffraction occurs, and the position of diffraction can determine the crystal phase of the crystal;

[0063] 2. According to the Bragg diffraction equation, nλ=2dsinθ, wherein θ is the angle between the incident beam and the diffraction plane, λ is the X-ray wavelength, d is the crystal face spacing, and n is the crystal face spacing. When X-rays are diffracted on the corresponding crystal face, the X-ray diffraction intensity reaches the strongest;

[0064] 3. According to the crystal system to which different SiC crystal forms belong, such as the commonly used 3C, 4H, 6H, 15R crystal forms, C, H and R respectively represent that the crystal structure belongs to cubic crystal system, hexagonal crystal system and trigonal crystal system. The crystal direction is calculated by using the relationship between the crystal face spacing d and the crystal rod parameters a, c and the Miller index h, k, l;

[0065] 4. The position of the SiC sample to be tested is adjusted so that the X-ray spot can irradiate in the region to be tested. According to the approximate orientation of the crystal to be tested or the table, the standard reference 2θ Bragg diffraction angle of different crystal forms on different diffraction planes is compared and analyzed with the measured 2θ, and the crystal form and the measured diffraction plane of the region are obtained. Tables 1-3 below are respectively the 2θ angles of different diffraction planes of 4H single crystal, 6H single crystal and 15R single crystal:

[0066] Table 1 Corresponding table of part of crystal face and 2θ Bragg angle of 4H crystal SiC

[0067]

[0068] Table 2 Corresponding table of part of crystal face and 2θ Bragg angle of 6H crystal SiC

[0069]

[0070]

[0071] Table 3 Corresponding table of part of crystal face and 2θ Bragg angle of 15R crystal SiC

[0072]

[0073] According to Tables 1-3, the SiC sidewall is tested by using XRD, the 2θ Bragg angles of 4H crystal form, 6H crystal form and 15R crystal form on the same diffraction surface are relatively close, and therefore the detection accuracy of XRD is worse than that of the present application.

[0074] The accuracy of the determination method of Examples 1-5 is represented by a deviation rate, and the calculation formula of the deviation rate is: deviation rate = (|crystal form area calculated by the example - crystal form area calculated by XRD| / crystal form area calculated by XRD) x 100, for example, the 4H deviation rate in Example 1 = (|4H crystal form area calculated by Example 1 - 4H crystal form area calculated by XRD| / 4H crystal form area calculated by XRD) x 100.

[0075] The test results of the deviation rate are shown in Table 4, and the deviation rate in Table 4 refers to the average deviation rate of five silicon carbide crystal rods.

[0076] This experimental example is only used to verify the accuracy of the present application, and therefore a certain deviation rate is calculated in Table 4, and the polytype detection results of the sidewall of the silicon carbide crystal rod obtained by the quantitative test of the present application are more accurate than the XRD test results.

[0077] Table 4

[0078]

[0079]

[0080] In each example in Table 4, since the types of silicon carbide single crystal rods are different, for each crystal form of the silicon carbide single crystal rod, the deviation rate of the main crystal form is used as the basis for measuring the accuracy of the determination method, for example, in the above-mentioned examples, the 4H deviation rate is mainly used for the 4H-silicon carbide single crystal rod, and the smaller the value represents the more accurate the detection method of the example, and the 6H deviation rate is mainly used for the 6H-silicon carbide single crystal rod.

[0081] For 4H-SiC, 6H and 15R crystal forms are symbiotic polymorphs, wherein 15R crystal form is a transition crystal form in the transition process of 4H and 6H, and in the XRD test, because the test spot is large, when 15R and 4H or 6H exist at the same time, 15R is easily identified as 4H or 6H, and in the transition process of 4H to 15R and 15R to 6H, different crystal form characteristic peaks will appear in the same spectrum, so it is difficult to accurately identify 15R crystal form according to the peak strength ratio of the characteristic peaks, and 15R crystal form is easily identified as 4H or 6H crystal form, so that the 15R deviation rate of the 4H-silicon carbide single crystal rod measured in each embodiment is the highest, and the test conclusion is consistent with the actual crystal form transition process. In the polymorphic symbiosis of 4H-silicon carbide single crystal rod, the test method of the application has a higher test deviation rate on 15R crystal form than XRD test, and can also prove that the detection method of the application can more subtly and quantitatively analyze the polymorphic symbiosis of the silicon carbide crystal rod compared with XRD.

[0082] The above is only an embodiment of the application, and the protection scope of the application is not limited by the specific embodiments, but is determined by the claims of the application. The application can have various changes and variations for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the technical idea and principle of the application shall be included in the protection scope of the application.

Claims

1. A method for determining the crystal form of a silicon carbide single crystal polymorphic coexistence region, characterized by, The method comprises the following steps: (1) testing: performing Raman testing on the silicon carbide single crystal to obtain a test spectrum, and classifying the characteristic peaks in the test spectrum into first crystal type Raman characteristic peaks and second crystal type Raman characteristic peaks according to the Raman characteristic peaks of different crystal types; (2) determination: if RPS1 / RPS2≥10 and 0.5≤RPS2 / I Baseline ≤5, the crystal form at the test point is the first crystal form; if 0.1≤RPS1 / RPS2<10 and RPS1 / I Baseline ≥2, RPS2 / I Baseline ≥2, the crystal form at the test point is the coexisting crystal form of the first crystal form and the second crystal form; if RPS1 / RPS2<0.1 and 0.5≤RPS1 / I Baseline ≤5, the crystal form at the test point is the second crystal form, wherein RPS1 is the peak intensity of the Raman characteristic peak of the first crystal form, RPS2 is the peak intensity of the Raman characteristic peak of the second crystal form, and I Baseline is the baseline peak intensity; the first crystal type is one of 4H crystal type, 6H crystal type or 15R crystal type, and the second crystal type is one of 4H crystal type, 6H crystal type or 15R crystal type; said 4H crystalline form Raman characteristic peak is 776.62 ± 1.00 cm -1 said 6H crystalline form Raman characteristic peak is 788.05 ± 1.00 cm -1 said 15R crystalline form Raman characteristic peak is 784.59 ± 1.00 cm -1 .

2. The method of claim 1, wherein the type of the silicon carbide single crystal polymorphic coexisting region is determined by the method. the Raman testing is microscopic Raman testing.

3. The method of claim 1, wherein the type of the polytypic region of the silicon carbide single crystal is determined by the method. The laser wavelength range of the Raman testing is 325 nm-785 nm.

4. The method of claim 1, wherein the type of the polytypic region of the silicon carbide single crystal is determined. The step moving step of the Raman testing is 3000 μm / step-15000 μm / step.

5. The method of claim 1, wherein the type of the polytypic region of the silicon carbide single crystal is determined. The light spot of the Raman testing is 1 μm-5 μm.

6. The method of claim 1, wherein The exposure time of the Raman testing is 0.5 s-10 s.

7. The method of claim 1, wherein the type of the polytypic region of the silicon carbide single crystal is determined. The Z-axis automatic focusing height range of the Raman testing is -100-+100 μm.

8. Application of the crystal type determination method of the silicon carbide single crystal polymorphic intergrowth region according to any one of claims 1-7 in crystal type detection of silicon carbide material.

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