Effects of rapid thermal annealing on the properties of GaNxAs1−x

Abstract

We report the effect of rapid thermal annealing on the valence-band splitting behavior of GaNxAs1−x films grown by molecular beam epitaxy. The light- and heavy-hole valence-band splitting induced by the elastic strain is observed in both photomodulated reflectance and photoluminescence spectra for as-grown GaNxAs1−x epilayers. The valence-band splitting energy increases with the nitrogen composition. This splitting is decreased with the increase of annealing temperature by the rapid thermal annealing temperature process. These properties have been well explained by strain relaxation model including both in-plane strain at GaAs/GaNAs interface and internal strain in GaNAs epilayer. These strain effects have been confirmed by x-ray diffraction and Raman measurements.