Visualisation of Ge Condensation in SOI

Abstract

AbstractWe use a novel technique CABOOM – Characterisation of Alloy concentration via Beveling, Oxidation and Optical Microscopy – to visualize the change of the Ge concentration sandwiched between two SiO2 layers during the Ge condensation process. CABOOM is very sensitive to variations in the gradient of the Ge concentration in the SiGe layer and thus gives a fast and simple way to interpret the condensation process. We present a systematic study of Ge condensation in a 120nm thick Si0.92Ge0.08 layer on a 60 nm Si body SOI (silicon-on-insulator) as a function of oxidation temperature and time, using CABOOM, SIMS and XRD. CABOOM shows the non-linear variation of the Ge diffusion as a function of process time.