InGaAs Compositional Control in a Halide-based Vapor Levitation Epitaxy System.

The Vapor Levitation Epitaxy (VLE) system utilizes quartz frits directly in front of the growth surface of the substrate. This impacts on both epitaxial layer thickness and compositional uniformity. The high uniform layers achievable with the process have been described. In this memo we discuss the compositional uniformity of InGaAs epitaxial layers grown by the VLE process. The composition of the InGaAs is shown to vary with time during a growth run and across the wafer when using the same growth conditions as for an open tube halide system. This compositional variation occurs for InGaAs layers exceeding 0.5microns in thickness. We show that with the proper gas phase composition, InGaAs epitaxial layers in excess of 5.0microns thick can be grown with excellent compositional uniformity.