Quantitative detection device and quantitative detection method for multiple types of side walls of silicon carbide crystal bar

Abstract

The invention discloses a quantitative detection device and a quantitative detection method for multiple types of side walls of a silicon carbide crystal bar, and belongs to the technical field of silicon carbide crystal bar detection. The quantitative detection device comprises a three-dimensional adjusting table, a distance measuring mechanism, a Raman detection mechanism, a conveying mechanism, a visual judgment mechanism and a control mechanism, wherein the three-dimensional adjusting table is used for placing a silicon carbide crystal bar to be detected and driving the silicon carbide crystal bar to be detected to rotate in a three-dimensional manner; the ranging mechanism is used for testing the thickness of the to-be-tested silicon carbide crystal bar; the Raman detection mechanism comprises a Raman detector, a detection pipeline, a corner lens and a detection port; the transmission mechanism is used for adjusting the distance between the three-dimensional adjusting table and the detection port; if focusing is abnormal, the visual judgment mechanism transmits information to the control mechanism, and the control mechanism controls the three-dimensional adjusting table and the conveying mechanism to achieve focusing. According to the device, the visual judgment mechanism, the three-dimensional adjusting table and the conveying mechanism are matched to realize automatic focusing of Raman laser, so that the detection precision and the detection efficiency are improved, and multi-type quantitative detection on the side wall of the silicon carbide crystal bar is realized.

Description

Technical Field

[0001] The present application relates to a quantitative detection device and a quantitative detection method for the polymorphism of the side wall of a silicon carbide crystal rod, and belongs to the technical field of silicon carbide crystal rod detection. Background Art

[0002] The currently industrialized silicon carbide substrate is first obtained by crystal growth to obtain SiC ingots, and then the silicon carbide ingots are prepared into standard-sized crystal rods through flat grinding and rolling. Finally, the crystal rods are obtained through multiple processing steps such as cutting, grinding, and polishing. However, during the SiC growth process, polymorphic symbiosis is prone to occur at the edge, and after mechanical processing such as flat grinding and rolling, it will be difficult to distinguish the polymorphic symbiosis defects at the edge of the crystal rod, making it difficult to provide effective processing guidance and suggestions for subsequent processing.

[0003] Most existing testing equipment uses normal light or polarized light for differentiation. When normal light is irradiated onto a conductive silicon carbide crystal rod, it presents different colors due to the different doping concentrations of the N element, which can distinguish the polytypes of the conductive silicon carbide crystal rod to a certain extent. However, for semi-insulating silicon carbide, normal light cannot distinguish the polytypes. Polarized light is mainly used for the detection of silicon carbide substrates. Since the edge roughness of the silicon carbide crystal rod changes after flat grinding and rounding, the penetration depth of the polarized light source on the carbon and silicon surfaces is shallow, making it difficult to accurately determine the distribution position of the polytype.

[0004] As the size and thickness of silicon carbide crystal rods on the market gradually increase, it is more difficult for the above two test methods to judge the polytype, and it is difficult to accurately identify the position of polytype co-existence, and both of the above two methods are difficult to achieve quantitative detection of silicon carbide crystal rods.

[0005] Currently, XRD can also be used for polymorphic detection of silicon carbide crystal rods. However, during the XRD detection process, the crystal needs to be erected and fixed to detect the side wall of the crystal rod. The position of the crystal rod needs to be readjusted after each detection. In addition, the XRD itself needs to adjust the angle of the X-ray before testing, which makes the XRD detection time very long, making it difficult to achieve large-scale detection of silicon carbide crystal rods. Summary of the invention

[0006] In order to solve the above problems, the present application proposes a quantitative detection device and quantitative detection method for the polymorphism of the side wall of a silicon carbide crystal rod. The device and method perform polymorphism detection on the silicon carbide crystal rod through Raman laser, wherein the cooperation of the visual judgment mechanism, the three-dimensional adjustment platform, and the transmission mechanism can realize automatic focusing during the detection process, improve the detection accuracy and detection efficiency, and realize quantitative detection of the polymorphism of the side wall of the silicon carbide crystal rod.

[0007] According to one aspect of the present application, a quantitative detection device for the polymorphism of the sidewall of a silicon carbide crystal rod is provided, comprising:

[0008] A three-dimensional adjustment platform, which is used to place the silicon carbide crystal rod to be tested and drive the silicon carbide crystal rod to be tested to rotate three-dimensionally;

[0009] A distance measuring mechanism, wherein the distance measuring mechanism is used to measure the thickness of the silicon carbide crystal rod to be measured;

[0010] A Raman detection mechanism, which can rise or fall, comprises a Raman detector, a detection pipeline, a corner lens and a detection port, and the detection port is arranged on one side of the three-dimensional adjustment platform;

[0011] A transmission mechanism, wherein the transmission mechanism is arranged below the three-dimensional adjustment platform, and the transmission mechanism is used to adjust the distance between the three-dimensional adjustment platform and the detection port;

[0012] The visual judgment mechanism is used to record the detection information of the Raman detection mechanism and judge whether it is focused. If the focusing is abnormal, the information is transmitted to the control mechanism, and the control mechanism controls the three-dimensional adjustment stage and the transmission mechanism to achieve focusing.

[0013] Optionally, the Raman detector is a microscopic Raman detector.

[0014] Optionally, a dimming mechanism is further included, and the dimming mechanism is used to adjust the brightness of the test point.

[0015] Optionally, the dimming mechanism is a white light lamp, and there are at least two white light lamps that are evenly distributed around the detection port.

[0016] Optionally, the distance measuring mechanism is a laser distance meter, and the laser distance meter is arranged above the conveying mechanism.

[0017] Optionally, the conveying mechanism is a conveyor belt.

[0018] According to another aspect of the present application, a quantitative detection method for the polymorphism of the sidewall of a silicon carbide crystal rod is provided, which is performed using any of the detection devices described above, and comprises the following steps:

[0019] (1) placing the silicon carbide ingot to be tested after flat grinding and rounding on a three-dimensional adjustment table, and placing the three-dimensional adjustment table on a transmission mechanism, the transmission mechanism transmits the three-dimensional adjustment table to an initial position for testing, the distance measuring mechanism tests the thickness of the silicon carbide ingot to be tested, and transmits the test result to the control mechanism to guide the rising or falling distance of the Raman detection mechanism;

[0020] (2) The Raman detector emits Raman laser, which is irradiated to the side wall of the silicon carbide ingot through the detection pipe, the corner lens and the detection port. The reflected Raman laser is then fed back to the Raman detector through the detection port, the corner lens and the detection pipe. During the process, the Raman detector rises or falls and the three-dimensional adjustment stage rotates horizontally to achieve Raman detection of the side wall of the silicon carbide ingot;

[0021] (3) The visual judgment mechanism receives and records the field of view observation data of the corner lens and determines whether it is focused. If the focus is abnormal, the visual judgment mechanism transmits information to the control mechanism. The control mechanism controls the three-dimensional rotation of the three-dimensional adjustment stage and the distance between the three-dimensional adjustment stage and the detection port to achieve focusing until the side wall of the silicon carbide crystal rod is completely detected.

[0022] Optionally, the wavelength range of the Raman laser is 325nm-785nm.

[0023] Optionally, the Raman detector is a microscopic Raman detector.

[0024] Optionally, a dimming mechanism is also included. In step (3), the control mechanism can also control the dimming mechanism to adjust the brightness at the test point to achieve bright field focusing.

[0025] The side wall test spectrum of the silicon carbide ingot obtained in the above quantitative detection method is determined in the following manner to obtain quantitative characterization data of the polymorphism of the side wall of the silicon carbide ingot:

[0026] 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 a co-existing 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, 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, I Baseline is the baseline peak intensity.

[0027] The first crystal form is one of the 4H crystal form, the 6H crystal form or the 15R crystal form, and the second crystal form is one of the 4H crystal form, the 6H crystal form or the 15R crystal form;

[0028] The Raman characteristic peak of the 4H crystal form is 776.62±1.00cm -1 The Raman characteristic peak of the 6H crystal form is 788.05±1.00cm -1 The Raman characteristic peak of the 15R crystal form is 784.59±1.00cm-1 .

[0029] The beneficial effects of this application include but are not limited to:

[0030] 1. The quantitative detection device for the polymorphism of the side wall of the silicon carbide crystal rod provided in the present application, the transmission mechanism and the three-dimensional adjustment stage can realize the precise focusing of any test point on the side wall, and the Raman spectrum of the entire side wall of the silicon carbide crystal rod can be accurately obtained in combination with the Raman detection mechanism, and the Raman reference peaks of different crystal forms can be used to distinguish silicon carbides of different crystal forms.

[0031] 2. The quantitative detection device for the side wall polymorph of the silicon carbide crystal rod provided in the present application uses a visual judgment mechanism and a control mechanism to control a three-dimensional adjustment platform and a transmission mechanism, automatically focuses and adjusts the light intensity of the SiC crystal rod side wall, and performs mapping scanning on the SiC side wall according to a preset trajectory, and then combines the identification of characteristic peaks of different crystal forms, and finally can achieve quantitative differentiation of the crystal forms of the SiC side wall polymorphs.

[0032] 3. The quantitative detection method of the polymorphism of the side wall of the silicon carbide crystal rod provided in the present application can perform quantitative detection of the polymorphism of the side wall of the silicon carbide crystal rod after flat grinding and rounding. The detection result can provide guidance for the preparation of the early silicon carbide ingot and the subsequent processing of the silicon carbide crystal rod, so as to facilitate the preparation of silicon carbide substrates with better crystallization quality.

[0033] 4. The quantitative detection method for the polymorphism of the side wall of the silicon carbide crystal rod provided in the present application has the characteristics of high detection efficiency and low detection cost, and can realize batch detection of silicon carbide crystal rods and be promoted for industrial use. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] 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:

[0035] Figure 1 This is a schematic structural diagram of a device for quantitatively detecting polymorphism of a silicon carbide crystal rod side wall according to Example 1 of the present application;

[0036] Figure 2 This is a schematic structural diagram of a device for quantitatively detecting polymorphism of a silicon carbide crystal rod side wall according to Example 3 of the present application;

[0037] Figure 3 The Raman spectra of different crystal forms of silicon carbide crystal rods;

[0038] Figure 4 This is the crystal distribution diagram of the side wall of the silicon carbide crystal rod measured by the quantitative detection method involved in Example 7 of the present application.

[0039] List of parts and reference numerals:

[0040] 1. Three-dimensional adjustment table; 2. Distance measuring mechanism; 31. Raman detector; 32. Detection pipeline; 33. Corner lens; 34. Detection port; 4. Conveying mechanism; 5. White light lamp; 6. Silicon carbide crystal rod; 7. Clean room. DETAILED DESCRIPTION

[0041] In order to more clearly illustrate the overall concept of the present application, a detailed description is given below in an illustrative manner in conjunction with the accompanying drawings.

[0042] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0043] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0044] In addition, in the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0045] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0046] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0047] In the present application, unless otherwise clearly specified and limited, a first feature "above" or "below" a second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

[0048] Example 1

[0049] refer to Figure 1 The embodiment of the present application discloses a quantitative detection device for the polymorphism of the side wall of a silicon carbide crystal rod 6, comprising a three-dimensional adjustment platform 1, a distance measuring mechanism 2, a Raman detection mechanism, a transmission mechanism 4, a visual judgment mechanism and a control mechanism, wherein the three-dimensional adjustment platform 1 is used to place the silicon carbide crystal rod 6 to be tested and drive the silicon carbide crystal rod 6 to be tested to rotate three-dimensionally; the distance measuring mechanism 2 is used to test the thickness of the silicon carbide crystal rod 6 to be tested; the Raman detection mechanism can rise or fall, and the Raman detection mechanism comprises a Raman detector 31, a detection pipe 32, a corner lens 33 and a detection port 34, and the detection port 34 is arranged on one side of the three-dimensional adjustment platform 1; the transmission mechanism 4 is arranged below the three-dimensional adjustment platform 1, and the transmission mechanism is used to adjust the distance between the three-dimensional adjustment platform 1 and the detection port 34; the visual judgment mechanism is used to record the detection information of the Raman detection mechanism and judge whether it is focused. If the focusing is abnormal, the information is transmitted to the control mechanism, and the control mechanism controls the three-dimensional adjustment platform 1 and the transmission mechanism 4 to achieve focusing.

[0050] The visual determination mechanism and control mechanism of the quantitative detection device are not shown in the figure. When the device performs polymorphic detection, the Raman detection mechanism rises or falls to adjust the height position of the side wall of the silicon carbide crystal rod 6 to be tested. The basis for the height position adjustment comes from the thickness of the silicon carbide crystal rod 6 measured by the distance measurement mechanism 2. The rotation of the three-dimensional adjustment platform 1 along the Z axis adjusts the peripheral position of the silicon carbide crystal rod 6 to be tested. The mapping scan of the silicon carbide side wall can be achieved through the rotation of the Raman detection mechanism and the three-dimensional adjustment platform 1 to obtain the Raman test spectrum of the entire side wall of the crystal rod.

[0051] However, due to the roughness of the side wall of the silicon carbide crystal rod 6 after flat grinding and rounding, the overall side wall is frosted, and the side wall is an arc shape, which may cause abnormal focusing during the above-mentioned Mapping scanning process, thereby affecting the test signal-to-noise ratio, and further affecting the accuracy of the test results. Therefore, the quantitative detection device can realize field observation through the corner lens 33 and transmit the detection information to the visual judgment mechanism. When the visual judgment mechanism determines that it is out of focus (abnormal focusing), it transmits information to the control mechanism. The control mechanism can control the transmission mechanism 4 to adjust the distance between the three-dimensional adjustment stage 1 and the detection port 34, that is, adjust the focal length; secondly, it can control the three-dimensional adjustment stage 1 to rotate along the X-axis, Y-axis, and Z-axis to adjust the angle of the crystal rod. The above two adjustments are combined to achieve precise focusing, thereby obtaining accurate Raman test results, so as to quantitatively analyze the polymorphic distribution of the side wall of the silicon carbide crystal rod 6.

[0052] Specifically, the distance measuring mechanism 2 can be an instrument such as a scaleless tachymeter, an electromagnetic wave distance measuring instrument, etc., as long as it can accurately measure the thickness of the silicon carbide crystal rod 6 to be measured.

[0053] Specifically, the transmission mechanism 4 can be a conveyor belt, a transmission vehicle or a transmission plate, as long as it can adjust the distance between the three-dimensional adjustment platform 1 and the detection port 34 and adjust the focal length. When a transmission plate is used, a transmission component needs to be arranged below the transmission plate to realize the movement of the transmission plate. For example, a gear is arranged on the bottom surface of the transmission plate, and a rack meshing with the gear is arranged below the gear. The gear rotates to realize the movement of the transmission plate. For example, a push rod is arranged on one side of the transmission plate, and the movement of the transmission plate is realized by pushing the push rod.

[0054] Specifically, the ascent or descent of the Raman mechanism can be carried out in a common manner in the prior art. For example, the Raman mechanism is arranged on a coarse focusing screw, and the ascent and descent of the Raman mechanism as a whole is achieved by rotating the coarse focusing screw.

[0055] Specifically, in order to reduce interference during the detection process, the detection area of ​​the quantitative detection device is set in the clean room 7, which can reduce the interference of external substances on the detection.

[0056] As an implementation mode, the distance measuring mechanism 2 is a laser distance measuring instrument, and the laser distance measuring instrument is arranged above the conveying mechanism 4. The laser distance measuring instrument fixed above the conveying mechanism 4 is used. When the conveying mechanism 4 sends the three-dimensional adjustment stage 1 and the silicon carbide crystal rod 6 to be tested to the initial position for detection, the laser distance measuring instrument first uses the plane of the three-dimensional adjustment stage 1 as a reference. Then, when the crystal rod is transmitted through the laser distance measuring instrument, the laser distance measuring instrument measures the thickness of the crystal rod according to the height difference between the surface of the crystal rod and the plane of the three-dimensional adjustment stage 1, and transmits it to the control mechanism to guide the distance of the Raman detection mechanism to rise or fall.

[0057] As an embodiment, the conveying mechanism 4 is a conveyor belt. The conveyor belt is moved by a pulley, which can improve the stability of the three-dimensional adjustment platform 1. At the same time, this setting can adjust the distance between the three-dimensional adjustment platform 1 and the detection port 34 without changing the moving distance of the conveying mechanism 4, thereby reducing interference in the detection process and further improving the detection efficiency and detection accuracy. And because the above-mentioned Raman detection mechanism is in the clean room 7, the setting of the conveying mechanism 4 can also reduce the footprint of the device and improve the compactness of the structure of the device.

[0058] Example 2

[0059] The difference between this embodiment and embodiment 1 is that the Raman detector 31 is a microscopic Raman detector. Conventional Raman laser and microscopic Raman laser can both realize Raman detection of the side wall of the silicon carbide crystal rod 6, and obtain the Raman spectrum of the silicon carbide side wall, thereby realizing quantitative detection of polytypes. The microscopic Raman detector 31 can be combined with the corner lens 33 to realize microscopic observation of the test point on the basis of realizing the above detection, further improving the efficiency of the device in judging whether the test point is focused, thereby further improving the detection efficiency and detection accuracy.

[0060] Example 3

[0061] refer to Figure 2 , based on embodiment 2, this embodiment further includes a dimming mechanism, and the dimming mechanism is used to adjust the brightness of the test point.

[0062] During the detection process, when the focal length changes, the light intensity will change. When the Raman detection mechanism is used to achieve focusing, if there is no other dimming mechanism, focusing is achieved by adjusting the laser spot to the smallest and brightest. However, this focusing method has a certain focusing deviation compared to bright field focusing. If the laser wavelength is above 532nm, the focusing deviation can be ignored, and the device can still achieve quantitative detection of multiple types. However, if the laser wavelength is below 532nm, the focusing deviation will cause the detection point to remain in an abnormal focusing state, making it difficult to achieve quantitative detection of multiple types.

[0063] Through the external dimming mechanism, after the focal length is adjusted, the brightness of the field of view at the test point can be automatically adjusted according to the change in light intensity, thereby achieving bright field focusing in the optimal state, so that quantitative detection of the polymorphism of the side wall of the silicon carbide crystal rod 6 can still be achieved under low-wavelength laser.

[0064] As an implementation mode, the dimming mechanism is a white light lamp 5, and there are at least two white light lamps 5, which are evenly distributed around the detection port 34. The setting of the white light lamp 5 can improve the brightness at the test point, and can improve the dimming efficiency, which is convenient for rapid focusing. At the same time, the setting and position distribution of at least two white light lamps 5 can improve the brightness consistency around the test point, thereby improving the accuracy of Raman detection.

[0065] The following Examples 4-8 are quantitative detection methods using the devices in Examples 1-3, so the corresponding components are no longer numbered.

[0066] Example 4

[0067] This embodiment uses the quantitative detection device of Embodiment 1 to implement a quantitative detection method for the polymorphism of the side wall of a silicon carbide crystal rod, including the following steps:

[0068] (1) Placing the silicon carbide ingot to be tested after flat grinding and rounding on a three-dimensional adjustment table, and placing the three-dimensional adjustment table on a transmission mechanism, the transmission mechanism transmits the three-dimensional adjustment table to the initial position of the test, the distance measuring mechanism tests the thickness of the silicon carbide ingot to be tested, and transmits the test result to the control mechanism to guide the rising or falling distance of the Raman detection mechanism;

[0069] (2) An ordinary Raman detector emits Raman laser with a wavelength range of 785 nm. The Raman laser is irradiated to the side wall of the silicon carbide crystal rod through the detection pipe, the corner lens and the detection port. The reflected Raman laser is then fed back to the Raman detector through the detection port, the corner lens and the detection pipe to achieve Raman detection of the side wall of the silicon carbide crystal rod;

[0070] (3) The visual judgment mechanism receives and records the field of view observation data of the corner lens, and determines whether it is focused. If the focus is abnormal, the information is transmitted to the control mechanism. The control mechanism controls the distance between the three-dimensional adjustment stage and the detection port to achieve focal length adjustment, and controls the three-dimensional adjustment stage to rotate along the X-axis, Y-axis and Z-axis to achieve angle adjustment, thereby achieving focusing of the laser spot at the test point. After the focusing test is completed, the Raman detector is raised or lowered and the three-dimensional adjustment stage is horizontally rotated along the Z-axis to test the next test point until the mapping scan of the silicon carbide side wall is completed to obtain the Raman test spectrum of the entire side wall of the crystal rod, that is, the side wall of the silicon carbide crystal rod is fully detected.

[0071] Example 5

[0072] This embodiment uses the quantitative detection device of Embodiment 2 to implement a quantitative detection method for the polymorphism of the side wall of a silicon carbide crystal rod, including the following steps:

[0073] (1) Same as Example 4;

[0074] (2) The microscopic Raman detector emits Raman laser with a wavelength range of 632 nm. The Raman laser is irradiated to the side wall of the silicon carbide crystal rod through the detection pipe, the corner lens and the detection port. The reflected Raman laser is then fed back to the Raman detector through the detection port, the corner lens and the detection pipe to achieve Raman detection of the side wall of the silicon carbide crystal rod;

[0075] (3) Same as Example 4.

[0076] Example 6

[0077] The difference between this embodiment and embodiment 5 is that the wavelength range of the laser is 325 nm, and the rest is the same as embodiment 5.

[0078] Example 7

[0079] This embodiment uses the quantitative detection device of Embodiment 3 to implement a quantitative detection method for the polymorphism of the sidewall of a silicon carbide crystal rod, including the following steps:

[0080] (1) Same as Example 4;

[0081] (2) The microscopic Raman detector emits Raman laser with a wavelength range of 325 nm. The Raman laser is irradiated to the side wall of the silicon carbide crystal rod through the detection pipe, the corner lens and the detection port. The reflected Raman laser is then fed back to the Raman detector through the detection port, the corner lens and the detection pipe to realize Raman detection of the side wall of the silicon carbide crystal rod;

[0082] (3) The visual judgment mechanism receives and records the field of view observation data of the corner lens, and determines whether it is focused. If the focus is abnormal, the information is transmitted to the control mechanism. The control mechanism controls the distance between the three-dimensional adjustment stage and the detection port to adjust the focal length, and controls the three-dimensional adjustment stage to rotate along the X-axis, Y-axis and Z-axis to adjust the angle. At the same time, the control mechanism controls the power of the white light lamp to adjust the brightness of the field of view at the test point, so as to achieve bright field focusing at the test point under the optimal state. After the bright field focus test is completed, the Raman detector is raised or lowered and the three-dimensional adjustment stage is rotated horizontally along the Z-axis to test the next test point until the mapping scan of the silicon carbide side wall is completed to obtain the Raman test spectrum of the entire side wall of the crystal rod, that is, the side wall of the silicon carbide crystal rod is fully detected.

[0083] Example 8

[0084] The difference between this embodiment and embodiment 7 is that the wavelength range of the laser is 532 nm, and the rest is the same as embodiment 7.

[0085] Figure 3 The Raman spectra of different crystal forms of silicon carbide crystal rods are shown in Figure 4. Based on this, the test methods of Examples 4-8 are used to perform polymorphic detection and analysis on the silicon carbide crystal rods, and quantitative characterization of the polymorphic sidewalls of the silicon carbide crystal rods can be achieved.

[0086] The quantitative characterization diagram of the sidewall polymorphism of the 6-inch 4H-SiC crystal rod obtained by the test in Example 7 is as follows: Figure 4 As shown, Figure 4 The green one is 6H crystal form, the blue one is 15R crystal form, and the red one is 4H crystal form. Figure 4 The width of the 6H crystal measured in Figure (A) is 19246.8μm, and the width of the 15R crystal measured in Figure (B) is 7727.96μm.

[0087] Compared with Example 7, in Example 8, the laser wavelength range is increased, the test depth is increased, and the signal-to-noise ratio of the test signal is increased, so the recognition accuracy of the SiC crystal type is further improved.

[0088] Compared with Example 7, Examples 5 and 6 do not add a dimming mechanism. The test accuracy of Example 5 is higher than that of Example 6, which proves that the introduction of the dimming mechanism can increase the test accuracy at low wavelengths.

[0089] The conventional Raman detector used in Example 4 has a lower test accuracy than that of Example 7 using a micro Raman detector, but it can still achieve quantitative characterization of the polymorphism of the sidewall of the silicon carbide crystal rod, proving that micro Raman can have more precise control over the measured position, thereby improving the recognition accuracy.

[0090] For the present application, although XRD can also detect sidewall polymorphism, since the test spot of XRD itself is at the millimeter level, and the test spot of Raman in the present application is at the micrometer level, the test spot of XRD is larger than that of Raman. Both Raman and XRD can simultaneously measure multiple crystal forms of silicon carbide crystal rods, but when measuring the polymorphic symbiotic region, Raman and XRD will have multiple characteristic peaks of different crystal forms in their respective spectra. Because XRD has a relatively large spot coverage area, it is difficult to distinguish which crystal form is dominant in the crystal symbiotic region, so its test accuracy is low. The area tested by Raman in the present application is small, so the accuracy is relatively high.

[0091] Since the above embodiment is for testing 4H-SiC crystal rods, for 4H-SiC crystal rods, 4H is the required crystal form, and 6H and 15R are unnecessary polymorphic intergrowth crystal forms. However, if it is for 6H single crystal products or other crystal form products, 6H or other crystal forms are the required crystal forms, and the remaining other crystal forms are unnecessary polymorphic intergrowth crystal forms, and the test method of the above embodiment can still be used for testing.

[0092] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0093] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A quantitative detection device for polymorphism of the side wall of a silicon carbide crystal rod, characterized in that: include: A three-dimensional adjustment platform, which is used to place the silicon carbide crystal rod to be tested and drive the silicon carbide crystal rod to be tested to rotate three-dimensionally; A distance measuring mechanism, wherein the distance measuring mechanism is used to measure the thickness of the silicon carbide crystal rod to be measured; A Raman detection mechanism, which can rise or fall, comprises a Raman detector, a detection pipeline, a corner lens and a detection port, and the detection port is arranged on one side of the three-dimensional adjustment platform; A transmission mechanism, wherein the transmission mechanism is arranged below the three-dimensional adjustment platform, and the transmission mechanism is used to adjust the distance between the three-dimensional adjustment platform and the detection port; The visual judgment mechanism is used to record the detection information of the Raman detection mechanism and judge whether it is focused. If the focusing is abnormal, the information is transmitted to the control mechanism, and the control mechanism controls the three-dimensional adjustment stage and the transmission mechanism to achieve focusing.

2. The device for quantitatively detecting polymorphism of the side wall of a silicon carbide crystal rod according to claim 1, characterized in that: The Raman detector is a microscopic Raman detector.

3. The quantitative detection device for polymorphism of the side wall of a silicon carbide crystal rod according to claim 1, characterized in that: It also includes a dimming mechanism, which is used to adjust the brightness of the test point.

4. The device for quantitatively detecting polymorphism of the side wall of a silicon carbide crystal rod according to claim 3, characterized in that: The dimming mechanism is a white light lamp, and there are at least two white light lamps that are evenly distributed around the detection port.

5. The device for quantitatively detecting polymorphism of the side wall of a silicon carbide crystal rod according to claim 1, characterized in that: The distance measuring mechanism is a laser distance meter, and the laser distance meter is arranged above the transmission mechanism.

6. The device for quantitatively detecting polymorphism of the side wall of a silicon carbide crystal rod according to claim 1, characterized in that: The conveying mechanism is a conveyor belt.

7. A quantitative detection method for polymorphism of silicon carbide crystal rod sidewall, characterized in that: The method is carried out using the detection device according to any one of claims 1 to 6, and comprises the following steps: (1) The silicon carbide ingot to be tested after flat grinding and rounding is placed on a three-dimensional adjustment table. The transmission mechanism transmits the three-dimensional adjustment table to the initial position of the test. The distance measuring mechanism tests the thickness of the silicon carbide ingot to be tested and transmits the test result to the control mechanism; (2) The Raman detector emits Raman laser, which is irradiated to the side wall of the silicon carbide crystal rod through the detection pipe, the corner lens and the detection port for Raman testing; (3) The visual judgment mechanism receives and records the field of view observation data of the corner lens and determines whether it is focused. If the focus is abnormal, the information is transmitted to the control mechanism. The control mechanism controls the three-dimensional rotation of the three-dimensional adjustment stage and the distance between the three-dimensional adjustment stage and the detection port to achieve the focusing of the test point. After the test is completed, the Raman detector is raised or lowered and the three-dimensional adjustment stage is rotated horizontally to test the next test point until the side wall of the silicon carbide crystal rod is completely detected.

8. The method for quantitatively detecting polymorphism of the side wall of a silicon carbide crystal rod according to claim 7, characterized in that: The wavelength range of the Raman laser is 325nm-785nm.

9. The method for quantitatively detecting polymorphism of the side wall of a silicon carbide crystal rod according to claim 7, characterized in that: The Raman detector is a microscopic Raman detector.

10. The method for quantitatively detecting polymorphism of the side wall of a silicon carbide crystal rod according to claim 7, characterized in that: It also includes a dimming mechanism. In step (3), the control mechanism can also control the dimming mechanism to adjust the brightness at the test point to achieve bright field focusing.

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