The Defect Structure of GaP Crystals Grown from Gallium Solutions, Vapor Phase and Liquid Phase Epitaxial Deposition

Abstract

The defect structure of crystals grown from gallium solutions, vapor phase and liquid phase epitaxial deposition is described. Etchants have been used to demarcate emergent dislocations, stacking faults, and p‐n and n‐n⁺ junctions. Crystals grown from gallium solutions are inhomogeneous with respect to defect structure and contain substantial dislocation‐free regions. Evidence is cited which indicates that some dislocations are introduced during growth whereas others are apparently generated at high stress regions during cooling. It is demonstrated that vapor phase epitaxial deposition on substrates is capable of yielding nearly dislocation‐free crystals containing no stacking faults. The high density of defects observed in crystals grown on substrates is attributed to the heteroepitaxial mode of growth, in particular, the difference in thermal contraction of the growth layer and substrate on cooling from the growth temperature. diodes fabricated by liquid‐phase epitaxy, in contrast to those formed by vapor‐phase epitaxy, do not contain interfacial dislocations at the growth‐substrate interface, i.e., p‐n junction.