Influence of strain on the InAs1 – xSbx composition

Abstract

The composition of III–V semiconductor alloys with multiple group V elements results from a complex interaction of each group V species with each other and with group IIIs. Molecular beam epitaxy growth conditions, such as the group V absolute fluxes and flux ratios, substrate temperature, group III growth rate, the presence of surfactants, and the alloy's strain state, all affect the composition of InAs1 – xSbx. These factors are codependent in a manner that is far from completely established. In this work, the authors examine how the sign and degree of strain affects the film’s composition. In this study, the authors show that InAs1 – xSbx alloys have some ability to resist the creation of strain by self-adjusting the incorporation of the group V elements that would otherwise be changed in an unfavorable way (by, for example, a substrate temperature change). This self-latching to the substrate lattice constant is beneficial, since it means that the fluxes may not have to be adjusted as precisely as otherwise needed.