Effects of imperfections in InP avalanche photodiodes with vapor phase epitaxially grown p+-n junctions

The influences of growth conditions, substrate dislocation, and misfit dislocation on characteristics of p+-n junctions, which have been prepared by vapor phase epitaxy (VPE) growth, are studied. The gas flow rate ratio of InC1 and PH3 in the hydride VPE growth affects junction properties. One-to-one correlation does not exist between dislocation and fatal junction degradation for the grown junctions. Dislocation affects junction properties at low dislocation densities only near the breakdown, where photocurrent is multiplied by a factor of several tens. The results obtained suggest that other crystal defects are responsible for destructive junction failure at low dislocation densities.