Strain enhancement during annealing of GaAsN alloys.

Abstract

We have investigated the effect of rapid thermal annealing (RTA) on the optical and structural properties of GaAsN alloys using photoluminescence (PL) and double-crystal x-ray diffraction. We observe a significant anomalous strain enhancement during RTA and a blueshift of the PL peak energy accompanied by a reduction in the emission linewidth. The PL features are attributed to an improvement in the homogeneity of the alloy, and the strain enhancement reflects a change in N-related complexes during annealing. Based on a defect model, an interstitial nitrogen concentration of 1.8×1019 cm−3 is deduced prior to annealing