CN114999952A - Method for confirming M surface in gallium nitride substrate and method for cutting gallium nitride substrate - Google Patents

Abstract

The present application provides a method for confirming an M-plane in a gallium nitride substrate and a method for cutting the gallium nitride substrate, including: providing a gallium nitride substrate; selecting a scanning point on the upper surface of the gallium nitride substrate; Perform multiple rocking curve scans on the preset crystal plane of the gallium nitride substrate based on the scanning points to obtain multiple Omega curves and multiple scanning angles corresponding to the peaks of the multiple Omega curves; The W surface of the gallium nitride substrate is scanned at 360° Phi to obtain a plurality of Phi values corresponding to the M surface; The M-plane closest to the chamfered corner and the M-plane farthest from the chamfered corner in the gallium nitride substrate are determined. In the above method for confirming the M-plane in the gallium nitride substrate, the M-plane closest to the chamfer angle and the M-plane farthest from the chamfer angle can be accurately confirmed in the gallium nitride substrate.

Description

Confirmation method of M-plane in gallium nitride substrate and cutting method of gallium nitride substrate

technical field

The present application relates to the field of semiconductor technology, and in particular, to a method for confirming an M-plane in a gallium nitride substrate and a method for cutting the gallium nitride substrate.

Background technique

When growing a gallium nitride substrate, the physical plane (such as the upper surface) of the gallium nitride substrate and the direction of the gallium nitride unit cell often have a certain angle (that is, a chamfered angle). The gallium nitride unit cell is inclined towards a certain direction of the gallium nitride substrate. In the prior art, after a gallium nitride substrate is obtained, for a gallium nitride substrate with a chamfered angle, it is necessary to find the M surface of the gallium nitride substrate closest to the chamfered angle and the M plane farthest from the chamfered angle. face, so that the gallium nitride substrate can be cut according to the required face and other subsequent processing. However, at present, there is no effective method to accurately identify the M-plane closest to the chamfer angle and the M-plane farthest from the chamfer angle of the gallium nitride substrate.

SUMMARY OF THE INVENTION

Based on the problem in the prior art that the M-plane closest to the chamfer angle and the M-plane farthest from the chamfer angle of the gallium nitride substrate cannot be accurately confirmed, a method for confirming the M-plane in a gallium nitride substrate and the method are provided. Cutting method of gallium nitride substrate.

The present application provides a method for confirming the M-plane in a gallium nitride substrate, including:

Provide gallium nitride substrate;

selecting scanning points on the upper surface of the gallium nitride substrate;

Perform multiple rocking curve scans on the preset crystal plane of the gallium nitride substrate based on the scanning points to obtain multiple Omega curves and multiple scanning angles corresponding to the peaks of the multiple Omega curves;

360°Phi scanning is performed on the W surface of the gallium nitride substrate to obtain a plurality of Phi values corresponding to the M surface;

Based on a maximum scanning angle, a minimum scanning angle and a plurality of the Phi values among the plurality of scanning angles, the M-plane closest to the bevel angle and the bevel angle in the gallium nitride substrate are determined The farthest M face.

When growing a gallium nitride substrate, the physical plane (such as the upper surface) of the gallium nitride substrate and the direction of the gallium nitride unit cell often have a certain angle (that is, a chamfered angle). The gallium nitride unit cell is inclined in a certain direction of the gallium nitride substrate; in the above-mentioned method for confirming the M plane in the gallium nitride substrate, this inclination is used to preset the crystal plane on the gallium nitride substrate. Multiple rocking curve scans, multiple Omega curves and multiple scan angles corresponding to the peaks of the multiple Omega curves, and then perform multiple Phi scans on the W surface of the gallium nitride substrate to obtain multiple and M surfaces. The corresponding Phi value, and finally based on the maximum scanning angle, the minimum scanning angle and the multiple Phi values among the multiple scanning angles, the M-plane closest to the chamfering angle and the M-plane closest to the chamfering angle in the gallium nitride substrate can be accurately confirmed. far M face.

In one embodiment, the predetermined crystal plane of the gallium nitride substrate is scanned multiple times on the rocking curve based on the scanning points, so as to obtain multiple Omega curves and peaks corresponding to the multiple Omega curves Multiple scan angles, including:

Perform rocking curve scanning of the preset crystal plane on the gallium nitride substrate based on the scanning points to obtain the Omega curve of this step, and record the scanning angle corresponding to the peak of the Omega curve obtained in this step;

Rotate the gallium nitride substrate by a preset angle in the XY plane, and perform rocking curve scanning of the preset crystal plane on the scanning point again to obtain the Omega curve of this step, and record the Omega obtained in this step. The scan angle corresponding to the peak of the curve;

The previous step is repeated several times until the gallium nitride substrate is rotated by 360°, so as to obtain a plurality of Omega curves and a plurality of scanning angles corresponding to the peaks of the plurality of Omega curves.

In one embodiment, before performing the rocking curve scanning of the preset crystal plane on the gallium nitride substrate based on the scanning points, the method includes:

Select any point in the XY plane as the scan start angle point.

In one embodiment, the predetermined crystal plane is a (002) plane.

In one embodiment, the preset angle is 0.1°˜30°.

In one embodiment, the preset angle is 1°˜10°.

In one embodiment, the W plane of the gallium nitride substrate is a plane parallel to the intersection of the M plane of the gallium nitride substrate and the C plane of the gallium nitride substrate.

In one embodiment, the W plane of the gallium nitride substrate is a (114) plane or a (102) plane.

In one embodiment, the rotation angle of the gallium nitride substrate in the XY plane corresponding to the maximum scanning angle is denoted as a first angle, and the gallium nitride substrate corresponding to the minimum scanning angle The rotation angle in the XY plane is denoted as the second angle; based on the maximum scanning angle, the minimum scanning angle and the plurality of the Phi values among the plurality of scanning angles, it is determined that the slope of the The M-face closest to the chamfered angle and the M-face farthest from the chamfered angle, including:

Comparing the first angle with a plurality of the Phi values, the M plane corresponding to the Phi value whose absolute value of the difference with the first angle is less than or equal to the preset value is the gallium nitride substrate The upper M face farthest from the chamfered corner;

Comparing the second angle with a plurality of the Phi values, the absolute value of the difference between the second angle and the second angle is less than or equal to the M-plane corresponding to the Phi value of the preset value, that is, the gallium nitride The M-plane closest to the chamfered corner on the substrate.

In one example, the preset value is less than or equal to 31°.

The present application also provides a method for cutting a gallium nitride substrate, comprising:

Determine the M-plane closest to the chamfered angle and the M-plane farthest from the chamfered angle in the gallium nitride substrate by using the method for confirming the M-plane in the gallium nitride substrate as described in any of the above solutions M face;

The gallium nitride substrate is cut from the M-plane of the gallium nitride substrate closest to the bevel angle or from the M-plane of the gallium nitride substrate farthest from the bevel angle .

When growing a gallium nitride substrate, the physical plane (such as the upper surface) of the gallium nitride substrate and the direction of the gallium nitride unit cell often have a certain angle (that is, a chamfered angle). The gallium nitride unit cell is inclined towards a certain direction of the gallium nitride substrate; because in the above-mentioned method for confirming the M plane in the gallium nitride substrate, this inclination is used to pre-crystallize the gallium nitride substrate Multiple rocking curve scans of the surface, multiple Omega curves and multiple scan angles corresponding to the peaks of the multiple Omega curves, and then multiple Phi scans are performed on the W surface of the gallium nitride substrate to obtain multiple and M surfaces. The corresponding Phi value, and finally based on the maximum scanning angle, the minimum scanning angle and the multiple Phi values among the multiple scanning angles, the M-plane closest to the chamfering angle in the gallium nitride substrate and the chamfering angle can be accurately confirmed. The farthest M-plane; thus, it can be ensured that when the gallium nitride substrate 10 is cut, the M-plane closest to the chamfer angle in the gallium nitride substrate or the most chamfered angle in the gallium nitride substrate can be accurately The far M face is cut to ensure the cutting yield.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the traditional technology, the following briefly introduces the accompanying drawings that are used in the description of the embodiments or the traditional technology. Obviously, the drawings in the following description are only the For some embodiments of the application, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

FIG. 1 is a flowchart of a method for confirming an M-plane in a gallium nitride substrate provided in an embodiment of the application;

2 is a schematic top-view structural diagram of a gallium nitride substrate in a method for confirming an M-plane in a gallium nitride substrate provided in an embodiment of the present application;

3 is a schematic three-dimensional structure diagram of a gallium nitride unit cell in a gallium nitride substrate in a method for confirming an M-plane in a gallium nitride substrate provided in an embodiment of the application;

4 is a schematic cross-sectional structure diagram of a gallium nitride substrate in a method for confirming an M-plane in a gallium nitride substrate provided in an embodiment of the application;

FIG. 5 is a flowchart of a method for cutting a gallium nitride substrate provided in another embodiment of the present application.

Description of reference numerals: 10. Gallium nitride substrate; 101. Gallium nitride unit cell.

Detailed ways

In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the related drawings. Embodiments of the present application are presented in the accompanying drawings. However, the application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of the application are for the purpose of describing specific embodiments only, and are not intended to limit the application.

It will be understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element.

It can be understood that the "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between them.

As used herein, the singular forms "a," "an," and "the/the" can include the plural forms as well, unless the context clearly dictates otherwise. It should also be understood that the terms "comprising/comprising" or "having" etc. designate the presence of stated features, integers, steps, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more Possibilities of other features, integers, steps, operations, components, parts or combinations thereof.

Referring to FIG. 1, the present application provides a method for confirming an M-plane in a gallium nitride substrate, and the method for confirming an M-plane in a gallium nitride substrate may include the following steps:

S10: Provide gallium nitride substrate;

S11: selecting a scanning point on the upper surface of the gallium nitride substrate;

S12: Perform multiple rocking curve scans on the preset crystal plane of the gallium nitride substrate based on the scanning points to obtain multiple Omega curves and multiple scanning angles corresponding to the peaks of the multiple Omega curves;

S13: Perform 360° Phi scanning on the W surface of the gallium nitride substrate to obtain a plurality of Phi values corresponding to the M surface;

S14: Based on the maximum scanning angle, the minimum scanning angle and the plurality of the Phi values among the plurality of scanning angles, determine the M-plane closest to the chamfering angle in the gallium nitride substrate and the surface closest to the chamfering angle and the slanting angle. Chamfer the farthest M face.

When growing a gallium nitride substrate, the physical plane (such as the upper surface) of the gallium nitride substrate and the direction of the gallium nitride unit cell often have a certain angle (that is, a chamfered angle). The gallium nitride unit cell is inclined in a certain direction of the gallium nitride substrate; in the above-mentioned method for confirming the M plane in the gallium nitride substrate, this inclination is used to preset the crystal plane on the gallium nitride substrate. Multiple rocking curve scans, multiple Omega curves and multiple scan angles corresponding to the peaks of the multiple Omega curves, and then perform multiple Phi scans on the W surface of the gallium nitride substrate to obtain multiple and M surfaces. The corresponding Phi value, and finally based on the maximum scanning angle among the multiple scanning angles, the rotation angle in the XY plane corresponding to the minimum scanning angle, and the multiple Phi values, the chamfer angle in the gallium nitride substrate can be accurately confirmed. The nearest M-face and the M-face farthest from the chamfered angle.

In step S10 , referring to step S10 in FIG. 1 and FIGS. 2 to 4 , a gallium nitride substrate 10 is provided.

Specifically, the gallium nitride substrate 10 may have a crystal normal and a physical plane normal, and the physical plane normal may be the normal of the upper surface of the gallium nitride substrate 10 .

More specifically, the gallium nitride substrate 10 has a chamfered angle, and the chamfered angle of the gallium nitride substrate 10 is the angle α between the crystal normal and the physical plane normal, as shown in FIG. 4 .

In step S11 , referring to step S11 in FIG. 1 , scanning points are selected on the upper surface of the gallium nitride substrate 10 .

Specifically, in one example, any point on the surface of the gallium nitride substrate 10 can be selected as the scanning point; for example, the center point of the upper surface of the gallium nitride substrate 10 can be selected as the scanning point; of course, in other examples , the scanning point can also be any point on the upper surface of the gallium nitride substrate 10 , which is not limited here.

More specifically, in one example, the scan point can be recorded as point A.

In step S12 , referring to S11 in FIG. 1 and FIGS. 2 to 4 , the preset crystal plane of the gallium nitride substrate 10 is scanned for multiple times by rocking curve based on the scanning points, so as to obtain a plurality of Omegas Curve and multiple scan angles corresponding to peaks of multiple Omega curves.

In one example, in step S12, scanning points are selected on the upper surface of the gallium nitride substrate 10, and based on the scanning points, the preset crystal planes of the gallium nitride substrate 10 are scanned for multiple times by rocking curves, so as to obtain a plurality of Omega The curve and the plurality of scan angles corresponding to the peaks of the plurality of Omega curves may include the following steps:

S121: Scan the rocking curve of the preset crystal plane on the gallium nitride substrate 10 based on the scanning points to obtain the Omega curve of this step, and record the scanning angle corresponding to the peak of the Omega curve obtained in this step; in this step The scanning angle corresponding to the peak value of the obtained Omega curve is denoted as θ ₁ ';

S122: Rotate the gallium nitride substrate 10 by a preset angle in the XY plane (the preset angle can be denoted as B), the rotation in the XY plane of the crystal is represented by Phi, and perform the rocking curve of the preset crystal plane on the scanning point again Scan to obtain the Omega curve of this step, and record the scanning angle corresponding to the peak of the Omega curve obtained in this step; the scanning angle corresponding to the peak of the Omega curve obtained in this step is recorded as θ ₂ '; XY plane and GaN The upper surface of the substrate 10 is parallel, that is, the plane where the X axis and the Y axis are located in FIG. 1 is the XY plane, and the XY plane is the physical plane (ie, the upper surface) of the gallium nitride substrate 10 in FIG. 4 . parallel;

S123 : Repeat the previous step several times until the gallium nitride substrate 10 is rotated by 360° to obtain multiple Omega curves and multiple scanning angles corresponding to the peaks of the multiple Omega curves.

Specifically, before step S121, it may further include: selecting any point in the XY plane as the scanning starting angle point, and using the scanning starting angle point as the 0° starting point.

Specifically, in step S121 , the gallium nitride substrate 10 may be placed on an XRD single crystal diffractometer to perform rocking curve scanning of the preselected crystal plane at the scanning point.

In step S122 and step S123, the gallium nitride substrate 10 may continue to be placed on the XRD single crystal diffractometer to perform rocking curve scanning of the preselected crystal plane at the scanning point. Compared with step S121, the XRD single crystal diffractometer may be adjusted. The parameters above make the gallium nitride substrate 10 rotate by a predetermined angle in the XY plane.

In one example, the preset angle may be 0.1°˜30°, and specifically, the preset angle may be 0.1°, 1°, 5°, 10°, 15°, 20°, 25° or 30°, and so on. The smaller the preset angle is, the higher the accuracy is, but the smaller the preset angle is, the more times it needs to rotate and scan, and the more the judgment efficiency will be; on the basis of ensuring that accurate judgment results can be obtained, a reasonable value range should be selected As a preset angle, the judgment efficiency can be ensured on the basis of ensuring the accuracy of the judgment result. Preferably, the preset angle may be 1°˜10°, and in this embodiment, the preset angle may be 1°, 5°, 10°, and so on.

In steps S121 to S123 , how to perform the rocking curve scanning of the preset crystal plane on the scanning point is known to those skilled in the art, and will not be described here.

In step S123, step S122 is repeated several times. The number of times step S122 is repeated is related to the size of the preset angle. The smaller the preset angle is, the more times step S122 is repeated.

Specifically, every time the gallium nitride substrate 10 rotates, an Omega curve and a scan angle corresponding to the peak of the Omega curve will be obtained; taking the preset angle as B as an example to complete a 360° rotation, after the scan, a total of 360/B scanning angles can be obtained, which can be denoted as θ ₁ ', θ ₂ ', θ ₃ ', θ ₄ '...θ _n ', respectively; wherein, n=360/B.

It should be noted that, since each rotating side obtains an Omega curve and a scan angle corresponding to the peak of the Omega curve, the scan angle corresponding to each Omega curve and the peak of the Omega curve also corresponds to a gallium nitride substrate 10 in the XY plane. For example, taking the preset angle as B as an example, the rotation angle of the gallium nitride substrate 10 in the XY plane corresponding to the scanning angle corresponding to the Omega curve obtained for the first time and the peak value of the Omega curve is 0° , the rotation angle of the gallium nitride substrate 10 in the XY plane corresponding to the scanning angle corresponding to the Omega curve obtained after one rotation and the peak value of the Omega curve is B, the Omega curve obtained after rotating twice and the peak value of the Omega curve The rotation angle of the gallium nitride substrate 10 in the XY plane corresponding to the two corresponding scanning angles is 2B, and so on.

As an example, after obtaining multiple scanning angles, the multiple scanning angles are compared, and the samples corresponding to the maximum scanning angle θmax and the minimum scanning angle θmin of the multiple scanning angles can be selected from the multiple scanning angles in the XY plane The rotation angle of the sample in the XY plane corresponding to the maximum scanning angle θmax can be recorded as the first angle Phimax, and the rotation angle of the sample corresponding to the minimum scanning angle θmin in the XY plane can be recorded as the second angle Phimin . In steps S121 to S123, an Omega curve can be obtained for each scan, each Omega curve has a peak, and each peak of the Omega curve corresponds to a scanning angle during the scanning process of the XRD single crystal diffractometer. Each scan angle corresponds to a rotation angle of the gallium nitride substrate 10 in the XY plane.

In step S13 , referring to S12 in FIG. 1 and FIGS. 2 to 4 , a 360° Phi scan is performed on the W surface of the gallium nitride substrate 10 to obtain a plurality of Phi values corresponding to the M surface.

In one example, as shown in FIG. 3 , the gallium nitride unit cell 101 has a hexahedral column structure, and the W plane of the gallium nitride substrate 10 is the M plane of the gallium nitride substrate 10 and the gallium nitride substrate 10 . The plane of the intersection of the C plane (ie, the 0001 crystal plane) is parallel, such as the plane where the line segment AB and C'D' are located in Figure 3, the plane where the line segment A'B' and the line segment CD are located, etc.; GaN The (102) crystal plane and the (114) crystal plane in the substrate 10 are the W planes of the gallium nitride substrate 10 .

It can be seen from FIG. 3 that the gallium nitride unit cell 101 has a hexahedral column structure, and its side surface is the M surface of the gallium nitride substrate 10 , and there are 6 M surfaces in total; 6 Phi values corresponding to 6 M surfaces can be obtained by performing the Phi scans one-to-one, that is, each M surface corresponds to a Phi value of a Phi scan. The six Phi values can be denoted as Phi1, Phi2, Phi3, Phi4, Phi5 and Phi6, respectively. It should be noted that the Phi value here is the peak value corresponding to each M-plane during the Phi scanning process.

It should be noted that, how to perform 360°Phi scanning on the W surface of the gallium nitride substrate 10 is known to those skilled in the art, and will not be described here.

In step S14 , referring to step S13 in FIG. 1 and FIGS. 2 to 4 , based on the maximum scanning angle, the minimum scanning angle and the plurality of Phi values among the plurality of scanning angles, the slope of the gallium nitride substrate 10 is determined. The M-face closest to the chamfered corner and the M-face farthest from the chamfered corner.

In one example, in step S14, based on the first angle Phimax of the rotation of the gallium nitride substrate 10 in the XY plane corresponding to the maximum scanning angle among the plurality of scanning angles, and the minimum scanning angle among the plurality of scanning angles The second angle Phimin and a plurality of Phi values corresponding to the rotation of the gallium nitride substrate 10 in the XY plane determine the M-plane closest to the chamfered angle and the farthest from the chamfered angle in the gallium nitride substrate 10 The M side of , can include:

S141 : Compare the first angle Phimax with a plurality of Phi values, and the absolute value of the difference with the first angle Phimax is less than or equal to the preset value of the M surface corresponding to the Phi value, that is, the surface on the gallium nitride substrate 10 The M face farthest from the chamfered corner;

S142 : Compare the second angle Phimin with a plurality of Phi values, and the absolute value of the difference between the second angle Phimin and the second angle Phimin is less than or equal to the preset value of the M surface corresponding to the Phi value, that is, the surface on the gallium nitride substrate 10 The M-plane closest to the chamfered corner.

In one example, the preset value is less than or equal to 31°; specifically, the preset value may be 31°, 30°, 25°, 20°, 15°, 10°, or 5°, etc.; preferably, this implementation For example, the preset value may be 31°.

It should be noted that, among the multiple Phi values, there is only one Phi value whose absolute value of the difference with the first angle Phimax is less than or equal to the preset value, and the absolute value of the difference with the second angle Phimin is less than or equal to the preset value. There is only one Phi value for the set value, and each Phi value corresponds to an M-plane. Through the confirmation method of the M-plane in the gallium nitride substrate above, it can be accurately determined that the gallium nitride substrate 10 is closest to the chamfered angle. The M-plane and the M-plane farthest from the chamfered angle in the gallium nitride substrate 10 .

Please refer to FIG. 5 in conjunction with FIGS. 1 to 4 . The present application further provides a method for cutting a gallium nitride substrate. The method for cutting a gallium nitride substrate may include the following steps:

S20: Determine the M-plane closest to the chamfer angle in the gallium nitride substrate 10 and the M-plane farthest from the chamfer angle in the gallium nitride substrate 10;

S21 : The gallium nitride substrate 10 is cut from the M surface of the gallium nitride substrate 10 that is closest to the chamfer angle or from the M surface of the gallium nitride substrate 10 that is farthest from the chamfer angle.

When growing a gallium nitride substrate, the physical plane (such as the upper surface) of the gallium nitride substrate and the direction of the gallium nitride unit cell often have a certain angle (that is, a chamfered angle). The gallium nitride unit cell is inclined towards a certain direction of the gallium nitride substrate; because in the above-mentioned method for confirming the M plane in the gallium nitride substrate, this inclination is used to pre-crystallize the gallium nitride substrate Multiple rocking curve scans of the surface, multiple Omega curves and multiple scan angles corresponding to the peaks of the multiple Omega curves, and then multiple Phi scans are performed on the W surface of the gallium nitride substrate to obtain multiple and M surfaces. The corresponding Phi value, and finally based on the maximum scanning angle, the minimum scanning angle and the multiple Phi values among the multiple scanning angles, the M-plane closest to the chamfering angle in the gallium nitride substrate and the chamfering angle can be accurately confirmed. The farthest M-plane; thus, it can be ensured that when the gallium nitride substrate 10 is cut, the M-plane closest to the chamfered angle in the gallium nitride substrate 10 or the chamfered angle in the gallium nitride substrate 10 can be accurately aligned. The farthest M side is cut to ensure the cutting yield.

In one example, in step S20, the M-plane in the gallium nitride substrate 10 closest to the chamfered angle and the gallium nitride can be determined by the method for confirming the M-plane in the gallium nitride substrate as described in the above-mentioned embodiment. For the M-plane of the substrate 10 that is farthest from the chamfered angle, please refer to FIG. 1 to FIG. 4 and the description of the related embodiments for details, and will not be repeated here. .

In step S21, the gallium nitride substrate 10 may be cut by any existing gallium nitride substrate cutting method, for example, wire cutting or laser cutting, etc., and the specific cutting process is not limited here.

In the description of this specification, description with reference to the terms "one of the embodiments", "the other embodiment", etc. means that a particular feature, structure, material or feature described in connection with that embodiment or example is included in at least one implementation of the invention example or example. In this specification, schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

The technical features of the above-described embodiments can be combined arbitrarily. To simplify the description, all possible combinations of the technical features of the above-described embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the description in this specification.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (11)

1. A method for identifying an M-plane in a gallium nitride substrate, comprising:

providing a gallium nitride substrate;

selecting a scanning point on the upper surface of the gallium nitride substrate;

carrying out multiple swing curve scanning on a preset crystal face of the gallium nitride substrate based on the scanning point to obtain multiple Omega curves and multiple scanning angles corresponding to peak values of the multiple Omega curves;

scanning the W surface of the gallium nitride substrate by 360 degrees Phi to obtain a plurality of Phi values corresponding to the M surface;

and determining the M surface closest to the oblique cutting angle and the M surface farthest from the oblique cutting angle in the gallium nitride substrate based on the maximum scanning angle and the minimum scanning angle in the plurality of scanning angles and the plurality of Phi values.

2. The method for confirming the M-plane in the gallium nitride substrate according to claim 1, wherein the performing a plurality of rocking curve scans on the predetermined crystal plane of the gallium nitride substrate based on the scanning point to obtain a plurality of Omega curves and a plurality of scanning angles corresponding to peaks of the plurality of Omega curves comprises:

carrying out swing curve scanning on the preset crystal face of the gallium nitride substrate based on the scanning point to obtain an Omega curve of the step, and recording a scanning angle corresponding to a peak value of the Omega curve obtained in the step;

rotating the gallium nitride substrate by a preset angle in an XY plane, scanning the scanning point by the swing curve of the preset crystal face again to obtain an Omega curve of the step, and recording a scanning angle corresponding to the peak value of the Omega curve obtained in the step;

repeating the previous step for a plurality of times until the gallium nitride substrate rotates 360 degrees in the XY plane to obtain a plurality of Omega curves and a plurality of scanning angles corresponding to the peak values of the Omega curves.

3. The method for confirming the M-plane in the gallium nitride substrate according to claim 2, wherein before the scanning of the rocking curve of the preset crystal plane of the gallium nitride substrate based on the scanning point, the method comprises:

any point in the XY plane is selected as the scanning start angle point.

4. The method of confirming the M-plane in a gallium nitride substrate according to claim 2, wherein the predetermined crystal plane is a (002) plane.

5. The method of claim 2, wherein the predetermined angle is 0.1 ° to 30 °.

6. The method according to claim 3, wherein the predetermined angle is 1 ° to 10 °.

7. The method according to claim 1, wherein the W-plane of the gallium nitride substrate is a plane parallel to an intersection line between the M-plane of the gallium nitride substrate and the C-plane of the gallium nitride substrate.

8. The method of claim 7, wherein the gallium nitride substrate has a (114) plane or a (102) plane as a W plane.

9. The method according to any one of claims 2 to 8, wherein a rotation angle of the gallium nitride substrate in an XY plane corresponding to the maximum scanning angle is denoted as a first angle, and a rotation angle of the gallium nitride substrate in an XY plane corresponding to the minimum scanning angle is denoted as a second angle; determining an M-plane of the gallium nitride substrate closest to the chamfer angle and an M-plane of the gallium nitride substrate furthest from the chamfer angle based on a maximum scan angle, a minimum scan angle of a plurality of the scan angles and a plurality of the Phi values, comprising:

comparing the first angle with the Phi values, wherein the absolute value of the difference value between the first angle and the Phi values is smaller than or equal to the M surface corresponding to the Phi value with a preset value, namely the M surface which is farthest away from the chamfer angle on the gallium nitride substrate;

and comparing the second angle with the Phi values, wherein the absolute value of the difference value between the second angle and the Phi values is smaller than or equal to the M surface corresponding to the Phi value of the preset value, namely the M surface closest to the chamfer angle on the gallium nitride substrate.

10. The method of claim 9, wherein the predetermined value is less than or equal to 31 °.

11. A method for cutting a gallium nitride substrate, comprising:

determining the M-plane closest to the chamfer angle and the M-plane farthest from the chamfer angle in the gallium nitride substrate by using the method for determining the M-plane in the gallium nitride substrate according to any one of claims 1 to 10;

and cutting the gallium nitride substrate from the M surface of the gallium nitride substrate closest to the oblique cutting angle or the M surface of the gallium nitride substrate farthest from the oblique cutting angle.

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