The theoretical and experimental fundamentals of decreasing dislocations in melt grown GaAs and InP

Abstract

Abstract The availability of high quality substrate material is a prerequisite to future advances in the emerging high-speed electronic and photonic device/IC technologies. Consequently, significant progress has been made recently in reducing the dislocation densities in the bulk growth of GaAs and InP. We shall review the evidence implicating thermal-stress induced slip as the predominant mode of dislocation generation in these compounds. Then, the quasi-steady state heat transfer/thermal stress theory for defect generation in LEC growth together with its key predictions are outlined. Particular emphasis is placed on the degree of impurity hardening (reflected by an increase in the critical resolved shear stress) and ambient temperature gradient reduction as they relate to suppressing dislocation formation. We conclude by discussing the currently used experimental approaches to grow virtually defect-free single crystals, explain their shortcomings, and examine the outlook for future improvements.