The Effect of HfO2 Overlayer on the Thermal Stability of SiGe Substrate

Abstract

In this work we study the effect of various overlayers on the thermal stability of Si 0.8 Ge 0.2 substrate by X-ray photoelectron spectroscopy. Si 0.8 Ge 0.2 substrates were either covered with native oxide or were HF cleaned and subsequently covered with ∼1 nm thick HfO 2 . Our studies reveal different thermal behavior and germanium oxide stoichiometry for these samples. We showed that high temperature annealing (T A ≥1000 • C) results in Hf silicide formation, which is mostly correlated with thermal decomposition of silicon dioxide.