An automatic characterization method for three-dimensional length of grain boundaries by SEM-coupled nanorobot Z-axis height detection

Abstract

The invention belongs to the field of micro-nano measurement technology, and specifically discloses a method for automatically characterizing the three-dimensional length of a grain boundary by using a SEM coupled to a nanorobot for Z-direction height detection. The method comprises the following steps: step 1, placing a zinc oxide sample; polishing the zinc oxide sample, recording the polished surface as an X-Y plane, keeping the X-Y plane horizontal and upward, and placing the zinc oxide sample in a sample chamber of a SEM; step 2, obtaining a two-dimensional contour shape and length of a target grain boundary in the X-Y plane; step 3, automatically detecting the height difference of the target grain boundary contour at different Y values ​​in three-dimensional height; dividing the position points in the Y direction, then detecting the position points in the Y direction in the Z direction, and calculating the height difference; step 4, automatically detecting the height difference of the target grain boundary contour at different X values ​​in three-dimensional height; dividing the position points in the X direction, then detecting the position points in the X direction in the Z direction, and calculating the height difference; and step 5, virtually reconstructing the three-dimensional length of the target grain boundary.

Description

Technical Field

[0001] The invention belongs to the field of micro-nano measurement technology, and in particular relates to a method for automatically characterizing the three-dimensional length of a grain boundary by SEM-coupled nanorobot Z-direction height detection. Background Art

[0002] The excellent nonlinear conductivity characteristics exhibited by polycrystalline varistor functional materials are essentially the result of the coupling effect of internal grain boundaries. At present, most of the research on grain boundaries is aimed at measuring the electrical properties of grain boundaries. There is a lack of research on the automatic characterization of grain boundary structures, and there is a lack of data on the three-dimensional structure of grain boundaries, which makes it impossible to explain its relationship with the electrical properties of grain boundaries. In addition, when studying the grain boundary structure, the main focus is on characterizing its two-dimensional surface shape, and it is impossible to measure the length of the grain boundary. There is a lack of characterization methods and data for the three-dimensional length of the grain boundary, and the characterization method is single. When measuring grain boundaries, manual measurement is mostly used, which cannot meet the needs of automatic measurement and characterization of grain boundaries, and it is even more impossible to automatically measure the three-dimensional height of the grain boundary. Summary of the invention

[0003] The purpose of the present invention is to provide a method for automatically characterizing the three-dimensional length of grain boundaries by using a SEM coupled to a nanorobot for Z-direction height detection.

[0004] Based on the above purpose, the present invention adopts the following technical solution:

[0005] A method for automatically characterizing the three-dimensional length of grain boundaries by SEM-coupled nanorobot Z-direction height detection comprises the following steps:

[0006] Step 1, placing a zinc oxide sample; polishing the zinc oxide sample, recording the polished surface as the XY plane, keeping the XY plane horizontal and upward, and placing the zinc oxide sample in the sample chamber of the SEM;

[0007] Step 2, obtaining the two-dimensional contour shape and length of the target grain boundary in the XY plane;

[0008] Step 3, automatically detect the height difference of the target grain boundary contour at different Y values ​​in three dimensions; divide the position points in the Y direction, and then detect the position points in the Y direction in the Z direction to calculate the height difference;

[0009] Step 4, automatically detect the height difference of the target grain boundary contour at different X values ​​in three dimensions; divide the position points in the X direction, and then detect the position points in the X direction in the Z direction to calculate the height difference;

[0010] Step 5: Virtually reconstruct the three-dimensional length of the target grain boundary.

[0011] Furthermore, in step 2, the method for obtaining the two-dimensional contour shape and length of the target grain boundary in the XY plane is: using SEM to perform preliminary imaging of the grain boundary in the zinc oxide sample in the XY plane, and then selecting the grain boundary with a regular contour shape in the zinc oxide sample as the target grain boundary, and then using SEM to perform a second separate imaging of the target grain boundary in the zinc oxide sample in the XY plane to obtain the two-dimensional contour shape of the target grain boundary in the XY plane, and calculate the X-direction length and Y-direction length of the two-dimensional contour shape.

[0012] Furthermore, in step 3, the method of dividing the Y-direction position points is as follows: the target grain boundary contour is equally spaced along the Y direction into Y1, Y2, ..., Y n The n different positions of the n The n XZ faces of XZ1 , face Y XZ2 , ..., face Y XZn , the surface Y XZ1 , face Y XZ2 , ..., face Y XZn There are two positions along the X direction that intersect with the two-dimensional contour of the target grain boundary, and the two positions are called Y x11 , Y x21 , Y x12 , Y x22 , ..., Y x1n , Y x2n In step 4, the method of dividing the X-direction position points is as follows: divide the target grain boundary contour into X1, X2, ..., X along the X direction. n n different positions of the system will pass through different positions X1, X2, ..., X n The n YZ faces of YZ1 , Face X YZ2 , ..., face X YZn , the surface X YZ1 , Face X YZ2 , ..., face X YZn There are two positions along the Y direction that intersect with the two-dimensional contour of the target grain boundary, and the two positions are called X y11 , X y21 , X y12 , X y22 , ..., X y1n , X y2n .

[0013] Further, in step 3, the method of performing Z-direction detection on the Y-direction position point includes the following steps:

[0014] (3.1) Control the end of the nanorobot to move to position Y x11 The nanorobot is controlled to move downward along the Z direction until it contacts the position point Y. x11 The grain boundary at position Y x11 Carry out Z-direction height detection on the grain boundary at the

[0015] (3.2) Repeat step (3.1) and control the end of the nanorobot to move along position point Y x12 , Y x13 ,……, Y x1n Conduct Z-direction height detection of the grain boundaries at the first group of position points;

[0016] (3.3) Finally, control the end of the nanorobot to move to position point Y x21 The nanorobot is controlled to move downward along the Z direction until it contacts the position point Y. x21 The grain boundary at the detection position point Y x21 The Z-direction height of the grain boundary at ;

[0017] (3.4) Repeat step (3.3) and control the end of the nanorobot to move along position point Y x22 , Y x23 ,……, Y x2n Perform Z-axis height detection of the grain boundaries at the second set of position points.

[0018] Further, in step 4, the method of performing Z-direction detection on the X-direction position point includes the following steps:

[0019] (4.1) Control the end of the nanorobot to move to position point X y11 The nanorobot is controlled to move downward in the Z direction until it contacts the position point X. y11 The grain boundary at position point X y11 Carry out Z-direction height detection on the grain boundary at the

[0020] (4.2) Repeat the method of step (4.1) and control the end of the nanorobot to move along the position point X y12 , X y13 ,……, X y1n Conduct Z-direction height detection of the grain boundaries at the third group of position points;

[0021] (4.3) Finally, control the end of the nanorobot to move to position point X y21 The nanorobot is controlled to move downward in the Z direction until it contacts the position point X. y21 The grain boundary at position point X y21 Carry out Z-direction height detection on the grain boundary at the

[0022] (4.4) Then control the end of the nanorobot to move along the position point X y22 , X y23 , ..., X y2n Perform Z-axis height detection of the grain boundaries at the fourth set of position points.

[0023] Furthermore, in step 3, the method for calculating the height difference is: calculating the height difference between the grain boundary at each position point of the first group and the adjacent previous position point, and calculating the height difference between each position point of the second group and the adjacent previous position point. In step 4, the method for calculating the height difference is: calculating the height difference between the grain boundary at each position point of the third group and the adjacent previous position point, and calculating the height difference between each position point of the fourth group and the adjacent previous position point.

[0024] Furthermore, in step 5, the method for virtually reconstructing the three-dimensional length of the target grain boundary is: uploading the two-dimensional contour shape and length data of the target grain boundary in the XY plane, the height difference data of the grain boundary at all position points in the Y direction, and the height difference data of the grain boundary at all position points in the X direction to the host computer database, generating point cloud data of the three-dimensional length of the target grain boundary, and using the point cloud data to virtually reconstruct the three-dimensional length of the target grain boundary.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention solves the problems existing in the existing grain boundary characterization, such as the inability to achieve three-dimensional length characterization of grain boundaries, the inability to achieve Z-direction height detection, and the lack of three-dimensional information of grain boundaries. It can achieve functions such as single Z-direction height detection of the three-dimensional length of grain boundaries, automatic Z-direction characterization, and three-dimensional height characterization.

[0027] 2. The XY plane of the polished zinc oxide sample is controlled to be placed horizontally, so that the SEM can perform two-dimensional imaging of the XY plane of the polished zinc oxide sample, thereby providing basic conditions for the three-dimensional length characterization of the grain boundary of the zinc oxide sample.

[0028] 3. Use SEM to perform the first preliminary imaging of the grain boundaries in the zinc oxide sample in the XY plane, then select the target grain boundaries in the zinc oxide sample as the characterization object, and then use SEM to perform a second separate imaging of the target grain boundaries in the zinc oxide sample in the XY plane to obtain the two-dimensional contour shape and length of the target grain boundaries in the XY plane, thereby achieving the purpose of using SEM to perform two-dimensional XY plane length imaging of the target grain boundaries in the XY plane of the zinc oxide sample.

[0029] 4. Control the nanorobots to move along position point Y in sequence x11 , Y x12 , ..., Y x1nPerform the first set of Z-direction detection on the adjacent heights of the two-dimensional target grain boundary contour in the XZ plane, and control the nanorobot to successively move along the position point Y x21 , Y x22 , ……,Y x2n A second set of Z-direction detections are performed on the adjacent heights of the two-dimensional target grain boundary contour in the XZ plane to obtain the Z-direction adjacent heights at different positions of the two-dimensional target grain boundary contour in the XZ plane at different Y values, and the Z-direction relative height differences at adjacent positions of the two-dimensional target grain boundary contour in the XZ plane at different Y values ​​are calculated, thereby achieving the purpose of using nanorobots to perform three-dimensional automatic height detection of the Z-direction height of the two-dimensional target grain boundary contour in the XZ plane at different Y values.

[0030] 5. Control the nanorobots to move along position point X in sequence y11 , X y12 , ..., X y1n The first set of Z-direction detection is performed on the adjacent heights of the two-dimensional target grain boundary contour in the YZ plane, and the nanorobot is controlled to successively move along the position point X y21 , X y22 , ……,X y2n A second set of Z-direction detections are performed on the adjacent heights of the two-dimensional target grain boundary contour in the YZ plane to obtain the Z-direction adjacent heights at different positions of the two-dimensional target grain boundary contour in the YZ plane at different X values, and the Z-direction relative height differences at adjacent positions of different positions of the two-dimensional target grain boundary contour in the YZ plane at different X values ​​are calculated, thereby achieving the purpose of using the nanorobot to perform three-dimensional automatic height detection of the Z-direction height of the two-dimensional target grain boundary contour in the YZ plane at different X values.

[0031] 6. The point cloud data of the three-dimensional length of the target grain boundary is formed by using the two-dimensional contour shape and length data of the target grain boundary in the XY plane, the Z-direction relative height difference data in the XZ plane when the nanorobot detects different Y values, and the Z-direction relative height difference data in the YZ plane at different X values. The three-dimensional length of the target grain boundary is virtually reconstructed using the point cloud data, thereby realizing the three-dimensional length characterization and reconstruction of the grain boundary by SEM-coupled nanorobot Z-direction height detection, thereby achieving the purpose of three-dimensional characterization, Z-direction measurement, coupled characterization, and virtual reconstruction of the three-dimensional length of the grain boundary; it has the characteristics of automatic characterization, three-dimensional characterization, Z-direction measurement, coupled measurement, and virtual reconstruction. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a flow chart of Embodiment 1 of the present invention;

[0033] Figure 2 This is a flow chart of performing two-dimensional XY plane length imaging on a target grain boundary profile in Example 1 of the present invention;

[0034] Figure 3 This is a flow chart of automatic three-dimensional height detection of the Z-direction height difference in the XZ plane of a two-dimensional target grain boundary profile at different Y values ​​in Example 1 of the present invention;

[0035] Figure 4 This is a flow chart of automatic three-dimensional height detection of the Z-direction height difference of a two-dimensional target grain boundary profile in a YZ plane at different X values ​​according to Embodiment 1 of the present invention;

[0036] Figure 5 It is a schematic diagram of the position points in the Y direction of Example 1 of the present invention;

[0037] Figure 6 Schematic diagram of the position points in the X direction of Example 1 of the present invention. DETAILED DESCRIPTION

[0038] Example 1

[0039] A method for automatic characterization of the three-dimensional length of grain boundaries by SEM-coupled nanorobot Z-direction height detection, such as Figure 1-6 As shown, the following steps are included:

[0040] Step 1: Place the polished zinc oxide sample horizontally with its XY plane facing upward; polish the zinc oxide sample, record the polished surface as the XY plane, keep the XY plane horizontally upward, and place the zinc oxide sample in the sample chamber of the SEM. This allows the SEM to perform two-dimensional imaging of the XY plane of the polished zinc oxide sample, thereby providing basic conditions for characterizing the three-dimensional length of the grain boundary of the zinc oxide sample.

[0041] Step 2, using SEM to perform two-dimensional XY plane length imaging of the target grain boundary profile in the XY plane of the zinc oxide sample; Figure 2 As shown, when the polished zinc oxide sample is placed horizontally with the XY plane facing upward, the grain boundary in the zinc oxide sample is first imaged in the XY plane using SEM, and then the grain boundary with a regular outline shape in the zinc oxide sample is selected as the target grain boundary (a grain boundary with a regular outline shape is selected for the convenience of measurement, and a grain boundary can also be randomly selected), and the target grain boundary is used as the characterization object, and then the target grain boundary in the zinc oxide sample is imaged in the XY plane for the second time using SEM to obtain the two-dimensional outline shape of the target grain boundary in the XY plane, and calculate the X-direction length and Y-direction length of the two-dimensional outline shape. Thus, the purpose of using SEM to perform two-dimensional XY plane length imaging of the two-dimensional target grain boundary contour in the XY plane of the zinc oxide sample is achieved.

[0042] Step 3, using the nanorobot to automatically detect the Z-direction height difference of the two-dimensional target grain boundary contour in the XZ plane at different Y values; Figure 3 , Figure 5As shown; the position points of division in the Y direction: After the target grain boundary contour in the XY plane of the zinc oxide sample is imaged in the two-dimensional XY plane by SEM, the target grain boundary contour is first divided into Y1, Y2, ..., Y along the longest line segment in the Y direction of the two-dimensional contour shape. n The n different positions of the n The n XZ faces of XZ1 , face Y XZ2 , ..., face Y XZn , the surface Y XZ1 , face Y XZ2 , ..., face Y XZn There are two positions along the X direction that intersect with the two-dimensional contour of the target grain boundary, and the two positions are called Y x11 , Y x21 ,Y x12 , Y x22 , ..., Y x1n , Y x2n Then perform Z-direction detection on the Y-direction position point, the steps are as follows:

[0043] (3.1) Control the end of the nanorobot to move to position Y x11 The nanorobot tip is controlled to move downward in the Z direction until the nanorobot tip contacts the position point Y. x11 The grain boundary at position Y x11 Carry out Z-direction height detection on the grain boundary at the

[0044] (3.2) Repeat step (3.1) and control the end of the nanorobot to move along position point Y x12 , Y x13 ,……, Y x1n Conduct Z-direction height detection of the grain boundaries at the first group of position points;

[0045] (3.3) Finally, control the end of the nanorobot to move to position point Y x21 The nanorobot is controlled to move downward along the Z direction until it contacts the position point Y. x21 The grain boundary at the detection position point Y x21 The Z-direction height of the grain boundary at ;

[0046] (3.4) Repeat step (3.3) and control the end of the nanorobot to move along position point Y x22 , Y x23 ,……, Y x2n Perform Z-axis height detection of the grain boundaries at the second set of position points.

[0047] Finally, calculate the height difference: calculate the height difference between the grain boundary at each position point in the first group and the adjacent previous position point, that is, the height difference of the grain boundary at the nth position point in the first group is the position point Y x1n Grain boundary height at -Y x1n-1 The height of the grain boundary at the position Y is calculated; the height difference between each position point in the second group and the adjacent previous position point is calculated, that is, the height difference at the nth position point in the second group is the height difference at the position point Y x2n Grain boundary height at -Y x2n-1 The grain boundary height at .

[0048] Step 4, automatically detect the height difference of the target grain boundary contour at different X values ​​in three dimensions; Figure 4 , Figure 6 As shown, the X-direction position points are divided: along the longest line segment in the X direction of the two-dimensional contour shape, the target grain boundary contour is equally spaced into X1, X2, ..., X n n different positions of the system will pass through different positions X1, X2, ..., X n The n YZ faces of YZ1 , Face X YZ2 , ..., face X YZn , the surface X YZ1 , Face X YZ2 , ..., face X YZn There are two positions along the Y direction that intersect with the two-dimensional contour of the target grain boundary, and the two positions are called X y11 , X y21 , X y12 , X y22 , ..., X y1n , X y2n Then perform Z-direction detection on the X-direction position point, the steps are as follows:

[0049] (4.1) Control the end of the nanorobot to move to position point X y11 The nanorobot tip is controlled to move downward in the Z direction until the nanorobot tip contacts the position point X. y11 The grain boundary at position point X y11 Carry out Z-direction height detection on the grain boundary at the

[0050] (4.2) Repeat the method of step (4.1) and control the end of the nanorobot to move along the position point X y12 , X y13 ,……, X y1n Conduct Z-direction height detection of the grain boundaries at the third group of position points;

[0051] (4.3) Finally, control the end of the nanorobot to move to position point X y21The nanorobot is controlled to move downward in the Z direction until it contacts the position point X. y21 The grain boundary at position point X y21 Carry out Z-direction height detection on the grain boundary at the

[0052] (4.4) Then control the end of the nanorobot to move along the position point X y22 , X y23 , ..., X y2n Perform Z-axis height detection of the grain boundaries at the fourth set of position points.

[0053] Finally, calculate the height difference: calculate the height difference between the grain boundary at each position point in the third group and the adjacent previous position point, that is, the height difference of the grain boundary at the nth position point in the third group is the height difference of the position point X Y1n Grain boundary height at -X Y1n-1 The height of the grain boundary at the position point X is calculated; the height difference between each position point in the fourth group and the adjacent previous position point is calculated, that is, the height difference at the nth position point in the fourth group is the height difference at the position point X Y2n Grain boundary height at -X Y2n-1 The grain boundary height at .

[0054] Step 5, virtually reconstructing the three-dimensional length of the target grain boundary; uploading the two-dimensional contour shape and length data of the target grain boundary in the XY plane, the height difference data of the grain boundary at all positions in the Y direction, and the height difference data of the grain boundary at all positions in the X direction to the host computer database, uploading the grain boundary heights at all positions to the host computer database, generating point cloud data of the three-dimensional length of the target grain boundary, and using the point cloud data to virtually reconstruct the three-dimensional length of the target grain boundary.

Claims

1. A method for automatic characterization of three-dimensional length of grain boundaries by SEM-coupled nanorobot Z-direction height detection, characterized in that: The following steps are involved: Step 1, placing a zinc oxide sample; The zinc oxide sample is polished, and the polished surface is recorded as the XY plane. The XY plane is kept horizontally upward, and the zinc oxide sample is placed in the sample chamber of the SEM; Step 2, obtaining the two-dimensional contour shape and length of the target grain boundary in the XY plane; Step 3, automatically detect the height difference of the target grain boundary contour at different Y values ​​in three dimensions; divide the position points in the Y direction, and then detect the position points in the Y direction in the Z direction to calculate the height difference; Step 4, automatically detect the height difference of the target grain boundary contour at different X values ​​in three dimensions; divide the position points in the X direction, and then detect the position points in the X direction in the Z direction to calculate the height difference; Step 5, virtually reconstructing the three-dimensional length of the target grain boundary; In step 2, the method for obtaining the two-dimensional contour shape and length of the target grain boundary in the XY plane is: using SEM to perform preliminary imaging of the grain boundary in the zinc oxide sample in the XY plane, then selecting the grain boundary with a regular contour shape in the zinc oxide sample as the target grain boundary, and then using SEM to perform a second separate imaging of the target grain boundary in the XY plane in the zinc oxide sample to obtain the two-dimensional contour shape of the target grain boundary in the XY plane, and calculating the X-direction length and Y-direction length of the two-dimensional contour shape; In step 3, the method of dividing the Y-direction position points is as follows: divide the target grain boundary contour into Y1, Y2, ..., Y n The n different positions of the n The n XZ faces of XZ1 , face Y XZ2 , ..., face Y XZn , the surface Y XZ1 , face Y XZ2 , ..., face Y XZn There are two positions along the X direction that intersect with the two-dimensional contour of the target grain boundary, and the two positions are called Y x11 , Y x21 , Y x12 , Y x22 , ..., Y x1n , Y x2n In step 4, the method of dividing the X-direction position points is as follows: divide the target grain boundary contour into X1, X2, ..., X along the X direction. n n different positions of the system will pass through different positions X1, X2, ..., X n The n YZ faces of YZ1 , Face X YZ2 ,……, face X YZn , the surface X YZ1 , Face X YZ2 , ..., face X YZn There are two positions along the Y direction that intersect with the two-dimensional contour of the target grain boundary, and the two positions are called X y11 , X y21 , X y12 , X y22 , ..., X y1n , X y2n .

2. The method according to claim 1, characterized in that In step 3, the method for performing Z-direction detection on the Y-direction position point includes the following steps: (3.1) Control the end of the nanorobot to move to position Y x11 The nanorobot is controlled to move downward along the Z direction until it contacts the position point Y. x11 The grain boundary at position Y x11 Carry out Z-direction height detection on the grain boundary at the (3.2) Repeat step (3.1) and control the end of the nanorobot to move along position point Y x12 , Y x13 , ……,Y x1n Conduct Z-direction height detection of the grain boundaries at the first group of position points; (3.3) Finally, control the end of the nanorobot to move to position point Y x21 The nanorobot is controlled to move downward along the Z direction until it contacts the position point Y. x21 The grain boundary at position Y x21 Carry out Z-direction height detection on the grain boundary at the (3.4) Repeat step (3.3) and control the end of the nanorobot to move along position point Y x22 , Y x23 , ……,Y x2n Perform Z-axis height detection of the grain boundaries at the second set of position points.

3. The method according to claim 2, characterized in that In step 4, the method for performing Z-direction detection on the X-direction position point includes the following steps: (4.1) Control the end of the nanorobot to move to position point X y11 The nanorobot is controlled to move downward in the Z direction until it contacts the position point X. y11 The grain boundary at position point X y11 Carry out Z-direction height detection on the grain boundary at the (4.2) Repeat the method of step (4.1) and control the end of the nanorobot to move along the position point X y12 , X y13 , ……,X y1n Conduct Z-direction height detection of the grain boundaries at the third group of position points; (4.3) Finally, control the end of the nanorobot to move to position point X y21 The nanorobot is controlled to move downward in the Z direction until it contacts the position point X. y21 The grain boundary at position point X y21 Carry out Z-direction height detection on the grain boundary at the (4.4) Then control the end of the nanorobot to move along the position point X y22 , X y23 , ..., X y2n Perform Z-axis height detection of the grain boundaries at the fourth set of position points.

4. The method according to claim 2, characterized in that In step 3, the method for calculating the height difference is: calculating the height difference between the grain boundary at each position point of the first group and the adjacent previous position point, and calculating the height difference between each position point of the second group and the adjacent previous position point. In step 4, the method for calculating the height difference is: calculating the height difference between the grain boundary at each position point of the third group and the adjacent previous position point, and calculating the height difference between each position point of the fourth group and the adjacent previous position point.

5. The method according to claim 3, characterized in that In step 5, the method for virtually reconstructing the three-dimensional length of the target grain boundary is as follows: uploading the two-dimensional contour shape and length data of the target grain boundary in the XY plane, the height difference data of the grain boundary at all positions in the Y direction, and the height difference data of the grain boundary at all positions in the X direction to the host computer database, generating point cloud data of the three-dimensional length of the target grain boundary, and using the point cloud data to virtually reconstruct the three-dimensional length of the target grain boundary.

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