Electrical Compensation in InP Produced by Background Impurities and Structural Defects.

摘要

A steady-state liquid phase epitaxial growth system is being used to study the factors that influence the nucleation, growth and purity of InP. Humidity (>30% relative) has been found to be a major contaminant that leads to erratic growth morphologies and poor electrical properties. With the growth system and substrate preparations in a low humidity (<20% relative) room the reproducibility of epitaxial growths has been improved. The discoloration of the bone white pyrolytic boron nitride growth cell has helped to identify several sources of contamination that oxidize the In-melt and lead to premature nucleation. The nucleation and growth of epitaxial InP now appears to be limited by phosphorus transport instabilities in the P-saturated In-melt. A thermochemical analysis of phosphorus equilibria with In and InP may provide an insight into liquid solid stability conditions. The results are in excellent agreement with the stability of the In-P liquidus curve and InP substrates under PH3-H2 mixtures. The analysis appears to indicate that the partial pressure of P4 controls the nucleation of InP and the stability of the In-P liquidus curve. At temperatures below 700 deg C the partial pressure of P2 is greater than that for P4 and appears to stabilize the InP substrate degradation. (Author)