The Growth and Characterization of Large Size, High Quality, InP Single Crystals.

Single crystal InP wafers grown by both the Vertical Gradient Freeze (VGF) technique and the Liquid Encapsulated Czochralski (LEC) have been studied and compared in terms of overall quality. The techniques used to characterize the defect structure consist of 1. defect revealing etch; 2. transmission x-ray topography (TXRT) and 3. transmission cathodoluminescence (TCL). Subsequent to etching the VGF substrates were found to have a uniformly low (100/cm sup 2) EPD from the wafer edge to the center with no slip observed. The low defect density is independent of the sulphur doping level in the range 2x10 sup 17 -3x10 sup 18/cm sup 3 and is attributed to the reduced axial and radial temperature gradients during growth.