Determination of the Criterion for Morphological Classification of Etching Pits Formed in InSb Single Crystals Grown by the Czochralski Method in the [111] Crystallographic Direction and Doped with Tellurium

Abstract—Selective etching is used to assess the structural perfection (dislocation density) of single crystals in production conditions owing to its high informativity and relatively low laboriousness. However, the interpretation of data being obtained may vary depending on the choice of the type of regulatory documentation. The results of determining the criterion for the morphological classification of etching pits using digital image processing are presented. InSb (111) single crystals grown by the Czochralski method and doped with tellurium are analyzed. Using the sequential selective etching, it is established that the pointed-peaked pits on the InSb (111) surface, regardless of their size, are most likely of dislocation origin. In turn, clusters of pits of “regular” shape, which disappear during repeat etching, probably arise in sites where point defects emerge on the surface and are unrelated to the formation of Lomer–Cottrell barriers or other dislocation clusters. Based on an analysis of the brightness field, a criterion for differentiating etching pits is proposed by determining the value of the average pixel intensity. The results can be used in the production of structures for matrix and linear photodetectors, as well as in the optimization of technological parameters for the growth of single crystals using the Czochralski method.