JPS5490083A - Method of evaluating single crystal - Google Patents

Abstract

PURPOSE:To accomplish accurate evaluation of single crysals through an easy, definite detection of dislocation and compound dislocation in an InSb single crystal by selectvely applying an etching electrolyte composed of HF, H2O2 and H2O with a specified mixing ratio. CONSTITUTION:The surface of an InSb single crystal (III) is sliced into a wafer. The wafer thus obtained is polished and then smoothly etched to remove the material by about 80 mum. The wafer thus polished is etched at a room temperature by about 30 mum with an electrolyte composed of 49% HF, 30% H2O2 and H2O within a traingular region made by three points, (1:9:0), (9:1:0:) and (1:3:9:) in the illustrated ternary system. for example at a ratio of 1:2:2. Herein, the etching speed is about 1mum/sec. Then, the surface of the wafer thus treated is observed by an electron microscope. In this manner, compound dislocation can be easily and definitely detected. The composition of the electrolyte lies in the region made by three points, X, Y and Z in the drawing.