Crystal growth of InGaAs by the Bridgman method in microgravity

Abstract

Ternary compound semiconductors of In 1-x Ga x As (X=0.03) have been grown by the Horizontal Bridgman (HB) and the Vertical Bridgman (VB) methods on Earth and by the Bridgman method in microgravity in order to study a segregation phenomenon of Ga, which is strongly affected by a melt convection. The segregation coefficient (Keff) is 2.6 in a crystal grown in microgravity. This value is closer to unity than the value of 3.2 for a crystal grown by the HB method on Earth. Unfortunately we could not obtain a homogeneous Ga composition even in a seed part of a crystal grown in microgravity where the diameter is thinner. However, a crystal grown by the VB method on Earth shows a homogeneous concentration profile and an initial transient region, which means that the crystal was grown under the condition whereby melt convection was extremely suppressed.