Optical Constants of As-grown and RTA GaAs1-xNx Layers Analysed by Spectroscopic Ellipsometry

Abstract

In this work, we propose, for the first time, an analysis of the rapid thermal annealing (RTA) effect on GaAs1-xNx layers using spectroscopic ellipsometry (SE) on a set of as-grown and RTA GaAs1-xNx (x=0.1%, 0.5% and 1.5%) samples. This material being dedicated to several optoelectronic applications, an accurate knowledge of its optical properties is required to improve the selection of the layer thickness in a device system. The complex refractive indices are accurately determined, and the RTA effect on the samples is deduced. We have found that post-growth treatment (RTA) affects more samples with high nitrogen content, leading to an improvement of the optical constants. In addition, RTA is found to decrease the E1 transition energy nitrogen blue-shift.