Composition profiles in InP/InAsP quantum well structures under the effect of reactives gases during dry etching processes — Luminescence and SIMS

We have investigated the effects of reactive gases used during the deep reactive ion etching process of InP-based photonic structures in an inductively-coupled plasma (ICP) reactor. Samples with a specific structure, including 9 InAsP/InP quantum wells (QW) with graded As/P composition, were designed. Different chlorine-based gas chemistries were tested. Characterization was performed using cathodo-Iuminescence (CL) and photo-luminescence (PL) at different temperatures, and secondary ion mass spectrometry (SIMS). The luminescence lines display a blue shift upon exposure to the reactive gases, and a strong spectral sharpening. We discuss the influence of Cl diffusion and thermal processes during etching on these modifications.