Reduction of threading dislocation density in GaN using an intermediate temperature interlayer

GaN thin films with a reduced threading dislocation density have been produced by organometallic vapor phase epitaxy using an intermediate temperature interlayer. A description of the growth process is presented with characterization results. Reduction of the dislocation density was obtained by insertion of a single thin interlayer grown at an intermediate temperature after the initial growth at high temperature. A large percentage of the threading dislocations present in the first GaN epilayer are found to bend in the interlayer and do not propagate in the top layer grown at higher temperature in a lateral growth mode.