Studies of SiGe alloy surfaces after reactive ion etching

Reactive ion etching a characteristics of epitaxial Si1-xGex layers in SiCl4/Cl-2/N-2 plasma are investigated by different diagnostic techniques, such as Auger electron spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy. Surface morphology and stoichiometry are influenced by the dry etching process. A slight Ge enrichment at the etched SiGe films is explained by the different volatility of the corresponding chlorides. Moreover, a procedure which allows an exactly determined etch stop in a thin buried SiGe alloy - as a necessary requirement for the following surface analysis - is introduced.