Study of indium antimonide single crystals obtained by the modernized Chokhralsky method in several crystallographic directions

Abstract

Single-crystal indium antimonide InSb is an indispensable material in such branches of solid-state electronics as opto- and nanoelectronics. In turn, the dislocation density and the character of their distribution, which directly depend on the technological parameters of the growth process, considerably determine the physical and mechanical properties of the material. We present the results of studying InSb single crystals obtained by the modernized Czochralski method in the crystallographic directions [100], [111], and [112]. The effect of growth conditions (axial and radial temperature gradients at the crystallization front) on the dislocation structure of InSb plates and the structural properties of the plates were analyzed. Using the method of selective etching it was shown that the number of etching pits on the wafers with different orientations differs by approximately an order of magnitude (103 cm–2 for plane (111) and 102 cm–2 for (100)). Number of etch pits for the (100) plane is commensurate with their number in crystals grown in the [112] and [100] directions. Probably, the maximum dislocation density in InSb single crystals can be considered as a material constant, and the increased strength of single crystals grown at lower axial gradients at the crystallization front is related to the formation of a characteristic ensemble of point defects along the dislocation line through diffusion. It is shown that InSb wafers [112] (100) exhibit the best physical and mechanical properties. The results obtained can be used in the manufacture of structures for photodetectors, in particular, in plate processing (cutting, grinding and polishing) to optimize technological processes.