Spectroscopic Ellipsometry Analysis of Rapid Thermal Annealing Effect on MBE Grown GaAs1−x−Nx

Abstract

We report on the effect of rapid thermal annealing (RTA) on GaAs_1−x−N_x layers, grown by molecular beam epitaxy (MBE), using room temperature spectroscopic ellipsometry (SE). A comparative study was carried out on a set of GaAs_1−x−N_x as-grown and the RTA samples with small nitrogen content (x = 0.1%, 0.5% and 1.5%). Thanks to the standard critical point model parameterization of the GaAs_1−x−N_x extracted dielectric functions, we have determined the RTA effect, and its nitrogen dependence. We have found that RTA affects more samples with high nitrogen content. In addition, RTA is found to decrease the E1 energy nitrogen blueshift and increase the broadening parameters of E₁, E₁+Δ₁, E′₀ and E₂ critical points.