In situ determination of flux nonuniformities during molecular beam epitaxial growth

Abstract
We have observed an amplitude modulation superimposed on growth induced reflection high energy electron diffraction (RHEED) oscillations in molecular beam epitaxial growth of GaAs, AlSb, and GaSb. An analysis of spatially resolved luminescence measurements from a single GaAs/Al0.3Ga0.7As quantum well and RHEED oscillation data verifies an earlier suggestion of Van Hove and co‐workers that this modulation is related to nonuniform group III fluxes at the substrate. This phenomenon is very useful because it allows a quantitative in situ determination of group III flux nonuniformity. Furthermore, this study indicates that theories relating the decay of the RHEED oscillations to growth induced roughening of the surface should account for modifications that arise in the apparent decay rate because of flux nonuniformities.