(10-13) Detection Method of Twins in Oriented Hexagonal Wurtzite Structure Crystals

Abstract

The present invention discloses a method for detecting twins of a (10-13) oriented hexagonal wurtzite structure crystal. The detection method comprises: scanning the (0002) plane of a (10-13) oriented hexagonal wurtzite structure crystal with a high-resolution X-ray diffractometer in ω-2θ. If the obtained detection result contains a (10-11) diffraction peak, it is determined that twins exist, otherwise it is determined that no twins exist. The method for detecting twins of a (10-13) oriented hexagonal wurtzite structure crystal provided by an embodiment of the present invention has few test steps, a simple method, short time consumption, low cost, and is easy to easily determine twins.

Description

Technical Field

[0001] The present invention particularly relates to a method for detecting (10-13) oriented hexagonal wurtzite structure crystal twins, belonging to the technical field of semiconductor crystal material testing. Background Art

[0002] Hexagonal wurtzite AlN has a bandgap of up to 6.2eV and is one of the most promising ultraviolet luminescent materials. It is expected to overcome some problems of the current mercury lamp ultraviolet light source. Compared with mercury lamp light sources, AlN light sources have the advantages of no pollution, low operating voltage and low power consumption, showing the potential to replace mercury lamp light sources. The natural growth direction of wurtzite AlN is

[0001] orientation, and there is a strong quantum confined Stark (QCSE) effect along this direction, which greatly reduces the internal quantum luminescence efficiency of AlN devices. Growing AlN along the semi-polar direction can significantly reduce the QCSE effect, which has attracted the attention of many researchers in recent years.

[0003] The most commonly used heterogeneous substrate material for semi-polar AlN is the m-plane (10-10) sapphire substrate. There are three possible orientations on the m-plane sapphire substrate, namely the semi-polar (11-22) orientation, the (10-13) orientation and the non-polar (10-10) orientation. The preferred orientation depends on the nitridation conditions and the growth V / III ratio. Among them, the (10-13)-oriented AlN has attracted people's attention because of its weak positive polarization electric field, which is beneficial to prevent the leakage of hole states. However, since the (10-13)-oriented AlN is essentially epitaxially grown through the a-plane in the m-plane sapphire, and there are two equivalent a-planes in the m-plane sapphire, the (10-13)-oriented AlN is usually accompanied by twinning that is difficult to remove; the presence of twins leads to problems such as poor quality of AlN films, rough surface and reduced uniformity. However, there is currently a lack of effective means to simply and quickly determine the presence of (10-13) twins. Traditional transmission electron microscopy (TEM) testing will damage the sample, and the process is complicated and technically difficult. Scanning does not require damage to the sample, but it is time-consuming and complicated to operate, which is not conducive to rapid detection and judgment. Summary of the invention

[0004] The main purpose of the present invention is to provide a method for detecting (10-13) oriented hexagonal wurtzite structure crystal twins to overcome the deficiencies in the prior art.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0006] The embodiment of the present invention provides a method for detecting twins of a (10-13) oriented hexagonal wurtzite structure crystal, which comprises:

[0007] The (0002) plane of the (10-13) oriented hexagonal wurtzite structure crystal is scanned by a high-resolution X-ray diffractometer (HRXRD). If the obtained detection results contain the nitride (0002) and (10-11) diffraction peaks, it is determined that twins exist; otherwise, it is determined that no twins exist.

[0008] Compared with the prior art, the method for detecting twins of a (10-13) oriented hexagonal wurtzite structure crystal provided in an embodiment of the present invention has fewer testing steps, a simple method, short time consumption, low cost, and is easy to simply judge twins. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is the diffraction peak of the (0001) orientation of the AlN crystal and the (10-13) plane of the twin provided in a typical implementation case of the present invention.

[0010] Figure 2a It is a diffraction peak of the (10-13) plane of an AlN crystal with a (10-13) orientation provided in a typical embodiment of the present invention;

[0011] Figure 2b It is an ω-2θ scanning curve of the (0002) plane of an AlN crystal with a (10-13) orientation provided in a typical embodiment of the present invention;

[0012] Figure 3a It is a diffraction peak of the (10-13) plane of a GaN crystal with a (10-13) orientation provided in a typical embodiment of the present invention;

[0013] Figure 3b It is an ω-2θ scanning curve of the (0002) plane of a GaN crystal with a (10-13) orientation provided in a typical embodiment of the present invention;

[0014] Figure 3c A typical embodiment of the present invention provides a (0002) surface of a GaN crystal with a (10-13) orientation. Scan the curve. DETAILED DESCRIPTION

[0015] In view of the deficiencies in the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principle will be further explained as follows.

[0016] The embodiments of the present invention provide a non-destructive, rapid and easy-to-operate method for detecting (10-13) twins, which provides a new perspective and idea for in-depth understanding of the (10-13) twin structure and provides assistance for eliminating the twin structure.

[0017] The embodiment of the present invention provides a method for testing the existence of (10-13) oriented hexagonal wurtzite structure crystal twins by using the ω-2θ mode of HRXRD, which greatly improves the detection efficiency of (10-13) twins. The embodiment of the present invention provides a method for detecting (10-13) oriented hexagonal wurtzite structure crystal twins, directly performing ω-2θ scanning on the (0002) plane of the hexagonal wurtzite structure crystal, and rotating the χ angle of the hexagonal wurtzite structure crystal by a specific angle (31.6°-32.6°) during the test, so that the (0002) plane of the hexagonal wurtzite structure crystal is parallel to the direction of the incident X-ray line.

[0018] For example, taking AlN crystal as an example, if (10-13) twins exist, the (0002) diffraction peak of AlN, the (11-20) diffraction peak of Al2O3 and the (10-11) diffraction peak of AlN should appear in the test results, and the corresponding 2θ angles are 36.04°, 37.78° and 37.94° respectively; if (10-13) twins do not exist, only the (0002) diffraction peak of AlN and the (11-20) diffraction peak of Al2O3 will appear in the test results.

[0019] The embodiment of the present invention provides a method for detecting twins of a (10-13) oriented hexagonal wurtzite structure crystal, which comprises:

[0020] The hexagonal wurtzite structure crystal is placed in the [11-20] direction (determined according to the crystal orientation of the sapphire substrate positioning edge) parallel to the X-ray incident line, the corresponding χ angle is adjusted, and the (0002) plane of the (10-13) oriented hexagonal wurtzite structure crystal is scanned by a high-resolution X-ray diffractometer. If the obtained test results contain the (10-11) diffraction peak of AlN, it is determined that twins exist, otherwise it is determined that no twins exist.

[0021] Furthermore, the detection method comprises: under a fixed x-angle condition, a high-resolution X-ray diffractometer is used to perform a linkage scan on the (0002) plane of the (10-13) oriented hexagonal wurtzite structure crystal.

[0022] Furthermore, the detection method includes: making the [11-20] orientation of the crystal with hexagonal wurtzite structure (i.e., the sapphire substrate positioning edge) parallel to the X-ray incident line direction, and the sapphire positioning edge is the

[0001] crystal direction;

[0023] The χ angle of the (10-13) oriented hexagonal wurtzite structure crystal is set to a predetermined value so that the (0002) plane of the (10-13) oriented hexagonal wurtzite structure crystal is parallel to the direction of the incident x-ray line, and then the (0002) plane of the (10-13) oriented hexagonal wurtzite structure crystal is scanned from ω to 2θ using a high-resolution X-ray diffractometer.

[0024] Furthermore, the method includes: setting the χ angle of the (10-13) oriented hexagonal wurtzite structure crystal to a specific value; wherein the χ angle corresponding to AlN is 31.6°, the χ angle corresponding to GaN is 32.0°, the χ angle corresponding to InN is 31.8°, the χ angle corresponding to BN is 32.6°, and the χ angle of AlGaN and InGaN alloy materials can be determined according to Vieta's theorem.

[0025] Furthermore, the method specifically includes: performing ω-2θ linkage scanning at 30°-50° on the (0002) plane of the hexagonal wurtzite structure crystal sample.

[0026] Furthermore, the rotation step length of the (10-13) oriented hexagonal wurtzite structure crystal is 0.01°-0.05°.

[0027] Furthermore, when the diffraction peak of the (0002) plane includes the (0002) diffraction peak of nitride and the (10-11) diffraction peak of nitride, then the (10-13) oriented hexagonal wurtzite structure crystal has twins; when the diffraction peak of the (0002) plane only includes the (0002) diffraction peak of nitride, then the (10-13) oriented hexagonal wurtzite structure crystal does not have twins, wherein whether a sapphire substrate exists and whether a sapphire (11-20) diffraction peak appears does not affect the determination result.

[0028] Furthermore, the 2θ angles corresponding to the (0002) diffraction peak of the nitride, the (10-11) diffraction peak of the nitride and the (11-20) diffraction peak of the sapphire are the PDF card diffraction peaks corresponding to the hexagonal wurtzite structure crystals, for example, the 2θ angles corresponding to the (0002) diffraction peak and the (10-11) diffraction peak of A1N are 36.04° and 37.94° respectively; the 2θ angles corresponding to the (0002) peak and the (10-11) diffraction peak of GaN are 36.04° and 37.94° respectively. The 2θ angles corresponding to the diffraction peaks are 34.57° and 36.84° respectively; the 2θ angles corresponding to the (0002) diffraction peak and (10-11) diffraction peak of InN are 31.40° and 33.21° respectively; the 2θ angles corresponding to the (0002) diffraction peak and (10-11) diffraction peak of BN are 42.86° and 46.37° respectively; the 2θ angle corresponding to the (11-20) diffraction peak of Al2O3 is 37.78°.

[0029] Furthermore, the material of the (10-13) oriented hexagonal wurtzite structure crystal includes any one of AlN, GaN, BN, InN, AlGaN, InGaN and alloys formed by two or more thereof, but is not limited thereto.

[0030] Furthermore, the preparation method of the (10-13) oriented hexagonal wurtzite structure crystal includes any one of metal organic chemical vapor deposition, hydride vapor phase epitaxy, molecular beam epitaxy, physical vapor transport, and magnetron sputtering.

[0031] The technical solution, its implementation process and principle, etc. will be further explained below in conjunction with the accompanying drawings and specific implementation cases. Unless otherwise specified, the detection equipment used in the embodiments of the present invention can be those known to those skilled in the art.

[0032] Example 1

[0033] A method for detecting whether a semi-polar (10-13) AlN sample has twins, comprising:

[0034] 1) Providing AlN samples produced by any one of metal organic chemical vapor deposition, hydride vapor phase epitaxy, molecular beam epitaxy, physical vapor transport, and magnetron sputtering;

[0035] 2) Place the AlN sample on the sample stage of the HRXRD (high resolution x-ray diffraction) device, make the AlN [11-20] direction parallel to the X-ray incident direction, and perform an ω-2θ scan of the AlN sample from 10° to 110° with a step size of 0.1° to detect whether the AlN sample has a (10-13) orientation. The diffraction peak of the (10-13) orientation is located at 66.06°. The scanning results of the AlN sample with a (10-13) orientation are as follows: Figure 2a As shown;

[0036] 3) Rotate the χ angle of the A1N sample by 31.6° to make the (0002) plane parallel to the incident X-ray direction;

[0037] 4) Perform ω-2θ linkage scanning on the (0002) surface of the AlN sample in the test range of 30°-40°, with the test step length being any value between 0.01°-0.05°;

[0038] 5) Analyze the test results: Please refer to Figure 2b When the (0002) diffraction peak of AlN and the (10-11) diffraction peak of AlN appear in the scanning results, it is determined that the AlN sample has (10-13) twins. Figure 2bThe 2θ angles of the diffraction peaks are 36.04°, 37.78° and 37.94°, corresponding to the (0002) diffraction peak of AlN, the (11-20) diffraction peak of Al2O3 and the (10-11) diffraction peak of AlN, indicating the existence of twins.

[0039] Example 2

[0040] A method for detecting whether a semi-polar (10-13) GaN sample has twins, comprising:

[0041] 1) Providing a substrate-free GaN sample produced by any one of metal organic chemical vapor deposition, hydride vapor phase epitaxy, molecular beam epitaxy, physical vapor transport, and magnetron sputtering, and obtaining (10-13) oriented GaN by cutting;

[0042] 2) Place the GaN sample on the sample stage of the HRXRD (high resolution X-ray diffraction) device, make the GaN [11-20] direction parallel to the X-ray incident direction, and perform an ω-2θ scan of the GaN sample from 10° to 110° with a step size of 0.1° to detect whether the GaN sample has a (10-13) orientation. The diffraction peak of the (10-13) orientation is located at 63.43°, as shown in Figure 2. Figure 3a As shown, the GaN sample has a (10-13) orientation;

[0043] 3) Rotate the GaN sample's χ angle by 32.0° to make the (0002) plane parallel to the incident X-ray direction;

[0044] 4) Perform ω-2θ linkage scanning on the (0002) surface of the GaN sample in the test range of 30°-40°, with the test step length being any value between 0.01°-0.05°;

[0045] 5) Analyze the test results: Please refer to Figure 3b , only the diffraction peak at 34.57° (corresponding to the (0002) diffraction peak of GaN) appears in the scanning results, and the (10-11) peak at 36.84° does not appear, so there is no (10-13) twin in the GaN sample;

[0046] 6) Further adoption of general Scan to verify the existence of twins, and perform 0-360° scanning on the sample with a preset χ angle of 32° Scan with a step size of any value between 0.1-0.5°.

[0047] The scan results are as follows Figure 3c As shown, there is only one (0002) diffraction peak in the figure, confirming the absence of twins.

[0048] The embodiment of the present invention provides a method for detecting whether twins exist in a (10-13) oriented hexagonal wurtzite structure crystal. The method has few testing steps, is simple, short in time, low in cost, and is easy to determine twins.

[0049] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting twins in a (10-13) oriented hexagonal wurtzite structure crystal, characterized in that include: The x-angle of the (10-13) oriented hexagonal wurtzite structure crystal is set to a predetermined value, so that the (0002) plane of the (10-13) oriented hexagonal wurtzite structure crystal is parallel to the incident direction of the X-ray, and the (0002) plane of the (10-13) oriented hexagonal wurtzite structure crystal is linked to scan by the ω-2θ mode of the high-resolution X-ray diffractometer. When the diffraction peak of the (0002) plane includes the (0002) diffraction peak of the nitride and the (10-11) diffraction peak of the nitride, the (10-13) oriented hexagonal wurtzite structure crystal has twins; when the (0002) plane has a diffraction peak of the (0002) plane, the (10-11) diffraction peak of the nitride is greater than the (0002) plane. When the diffraction peak of the (0002) plane only includes the (0002) diffraction peak of the nitride, there is no twin in the (10-13) oriented hexagonal wurtzite structure crystal, wherein the material of the (10-13) oriented hexagonal wurtzite structure crystal includes any one of AlN, GaN, BN, InN, AlGaN, and InGaN, the χ angle corresponding to AlN is 31.6°, the χ angle corresponding to GaN is 32.0°, the χ angle corresponding to InN is 31.8°, the χ angle corresponding to BN is 32.6°, and the χ angle of AlGaN and InGaN alloy materials is determined according to the Vieta theorem.

2. The detection method according to claim 1, characterized in that include: The sapphire substrate positioning edge with hexagonal wurtzite structure crystal is parallel to the X-ray incident direction, wherein the sapphire positioning edge is the [11-20] orientation of the hexagonal wurtzite structure crystal; The hexagonal wurtzite structure crystal was scanned from 10° to 110° with a step size of 0.1° to detect whether the hexagonal wurtzite structure crystal has a (10-13) orientation. If the hexagonal wurtzite structure crystal has a (10-13) orientation, the χ angle of the (10-13) oriented hexagonal wurtzite structure crystal is set to a predetermined value, so that the (0002) plane of the (10-13) oriented hexagonal wurtzite structure crystal is parallel to the incident direction of the X-ray, and then a high-resolution X-ray diffractometer is used to perform an ω-2θ scan on the (0002) plane of the (10-13) oriented hexagonal wurtzite structure crystal, and the test step size is 0.01°-0.05°.

3. The detection method according to claim 2, characterized in that Specifically, the method comprises: performing ω-2θ scanning on the (0002) plane of a hexagonal wurtzite crystal having a (10-13) orientation, wherein the ω-2θ scanning angle is 30°-50°, and recording the diffraction peak of the (0002) plane.

4. The detection method according to claim 1, characterized in that: The 2θ angles corresponding to the (0002) diffraction peak of the nitride, the (10-11) diffraction peak of the nitride and the (11-20) diffraction peak of the sapphire are PDF card diffraction peaks corresponding to hexagonal wurtzite structure crystals.

5. The detection method according to claim 1, characterized in that: The preparation method of the (10-13) oriented hexagonal wurtzite structure crystal includes any one of metal organic chemical vapor deposition, hydride vapor phase epitaxy, molecular beam epitaxy, physical vapor transport, and magnetron sputtering.

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