Bulk III-V compound semi-conductor crystal growth

Within AT&T, III-V compound semiconductor crystals are used for the manufacture of photonic and high-speed integrated circuit devices. But commercial processes have limitations that prevent them from producing crystals of the quality these devices require. Therefore, AT&T has developed the vertical-gradient-freeze (VGF) technique into a process that can produce large, high-quality gallium phosphide (GaP), indium phosphide (InP), and gallium arsenide (GaAs) crystals. In this paper, we first survey the major crystal-growth processes and then present the improved results of VGF growth for InP and GaAs. The VGF-grown material has very low levels of crystalline defects distributed uniformly throughout the crystal. Growth striations are planar and are greatly reduced from those observed in other materials. We attribute the low defect density to reduced temperature gradients during growth.