Cathodoluminescence study of inductively coupled plasma (ICP) etched InP waveguide structures: Influence of the ridge dimension and dielectric capping

Abstract

This work is focused on the characterization of different defects introduced on InP material during the fabrication of classical photonic structures (ridge waveguides,…). These defects can arise from either the plasma etching procedure (reactive ion etching, RIE or inductively coupled plasma, ICP) or the reactive gases used in the etching procedure. The nature of the mask used for etching can also play a determinant role in the defect creation. The characterization of defects, which are susceptible to harm the devices performance, is essential in order to fabricate devices with improved performance and reliability. Due to the reduced dimensions of the studied features, the characterization techniques must combine a high spatial resolution with a spectral information that would permit an identification of the defects at a reduced spatial scale. The cathodoluminescence (CL) technique fulfils these requirements. We present herein a CL study of micrometric size waveguide structures made by ICP in InP substrates.