In the crystal, due to the high potential energy at the defect, the corrosion rate at the defect is high. In the appropriate etchant, when the corrosion rate at the defect is much higher than the corrosion rate of the intact crystal surface, dislocation pits and other marks will be formed at the defect. Various defects can be observed under a metallographic microscope. GB 11297.6-1989 Corrosion display and measurement method of dislocation pits of indium antimonide single crystal GB11297.6-1989 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Standard method for showing and measuringdislocation etch plts In Indium Antimonide single crystalUDC 661. 868. 274
: 621. 193. 4
GB 11297. 6--89
This method adopts nitric acid and hydrofluoric acid etchants, and is suitable for the display and measurement of α dislocations on the (111) surface of indium antimonide original wafers. The deviation of the measured surface from the (111) surface should not exceed 3°.
1 Principle
In a crystal, due to the high potential energy at the defect, the corrosion rate at the defect is relatively high. In a suitable etchant, when the corrosion rate at the defect is much higher than the corrosion rate of the intact surface, dislocation pits and other marks will be formed at the defect. Various defects can be observed under a metallographic microscope.
Dislocation density is usually used to measure the number of dislocations in a crystal. It can be defined as the total length of dislocation lines in a unit volume, roughly the number of dislocations exposed in a unit surface area, and the unit symbol used is cm-. Using nitric acid-hydrofluoric acid etchant, the dislocation lines form nipple-shaped corrosion pits at the exposed part of the (111) steel surface. If the observation area is A (cm\) and the number of corrosion pits is n, the dislocation density N (cm-2) is: Np= n/A
2 Measuring instruments and reagentswww.bzxz.net
2.1 Metallographic microscope.
2.2 Hydrofluoric acid: analytical grade + concentration 40%.
2.3 Nitric acid: analytical grade, concentration 65%~68%. 2.4 Deionized water.
3 Measurement steps
3.1 Sample preparation
3.1.1 Cut the sample according to the (111) steel surface, clean and degrease, and grind it with metallographic sandpaper with a particle size of no more than 20um or diamond with a particle size of no more than 10μn to remove the mechanical damage caused by cutting. After cleaning, there should be no scratches visible to the naked eye on the sample surface. 3.1.2 Prepare the corrosive agent, the ratio of which is HF:HNO,-1:1 (volume ratio). 3.1.3 Corrode the sample with the corrosive agent for 5~10 s. The length of the corrosion time depends on the temperature of the corrosive agent. After corrosion, wash with deionized water and absorb the water with filter paper.
3.2 Observation of dislocation
3.2.1 First, observe whether there are macroscopic defects on the sample and the distribution of dislocation pits with the naked eye. 3.2.2 Observe the dislocation density under a metallographic microscope. The field of view area can be selected according to the smallness of the dislocation pits: N<2×10\cm-, the field of view area is about 2mm\. N,=2×102~1×10°cm-2, the field of view area is about 1mm*. Approved by the Ministry of Machinery and Electronics Industry of the People's Republic of China on 198B-10-09 and implemented on January 1, 1990
GB11297.6--89
N>1X10cm-2 The field of view area is about 0.5mm. 3.2.3 Measurement point selection method
When Ns<2×10°cm\, the field of view is scanned on the entire sample (except 2mm from the edge), and the total number of pits in all the fields of view is counted. Then the total area of ​​the sample is measured and the dislocation density is calculated. N. When Ns is 2×10*~1×10cm-, find a point with the maximum dislocation density on the circumference 2mm away from the edge, take an average of five points on the diameter passing through this point, and then take an average of five points on another diameter perpendicular to this diameter. The center point is only counted once. The dislocation density is calculated using the average value of these nine points, as shown in the figure below. When Ns is 1×10cm-\, take two points, namely the center point and the point with the maximum dislocation density within the circumference 2mm away from the edge. 2m
Figure 1 Schematic diagram of the nine-point method
GB 11297.6—89
Appendix A
Defect images in indium antimonide single crystals
(reference)
This appendix provides some pictures of dislocation pits and other defect marks in indium antimonide crystals for identification reference only. Please see the additional notes of the single volume
This standard was drafted by the 11th Institute of the Ministry of Machinery and Electronics Industry. The main drafter of this standard is Li Wenhua.
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