Crystal Growth of BixSb1–x Solid Solutions with an Ultrasound Presence in Two Orthogonal Directions

Abstract

A modified Stepanov method of crystal growth with the application of ultrasound in two orthogonal directions was developed to reduce the component inhomogeneity. Ultrasonic waves at frequencies of 2.5 and 5 MHz were introduced into the melt parallel and perpendicular to the pulling axes of the grown crystals. BixSb1–x solid solution crystals were grown with a square and round cross section. The crystals grown with a square cross section had a smaller Sb inhomogeneity than the crystals with round cross section. They were grown in the presence of ultrasound simultaneously in two orthogonal directions in the melt and increased pulling rate. We explain the effect of two orthogonal standing waves to eliminate convection in the melt under the solid–liquid interface inside of a graphite die due to complex oscillation of the melt particles. The component inhomogeneity was measured before and after melt crystallization in a Czochralski crucible by a radioactive analysis method. The component inhomogeneity after me...