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 techni ques, such as Auger electron spectroscopy, X-ray photoelectron spectro scopy, and atomic force microscopy. Surface morphology and stoichiomet ry are influenced by the dry etching process. A slight Ge enrichment a t the etched SiGe films is explained by the different volatility of th e corresponding chlorides. Moreover, a procedure which allows an exact ly determined etch stop in a thin buried SiGe alloy - as a necessary r equirement for the following surface analysis - is introduced.