Oxide masked polySilicon/polygermanium 0.18 mu m gates were etched in high density plasma sources. Using gas mixtures of Cl-2 and HBr with O-2 which are commonly used for polysilicon, we observed strong deformation of the poly-Si/poly-Ge gate profiles, whereas perfectly anisotropic etching profiles were obtained for poly-Si gates. A multistep etching recipe was developed allowing anisotropic etching profiles to be obtained while maintaining a good selectivity to the gate oxide when using a Cl-2/N-2 gas mixture. The chemical constituents present on the tops, sidewalls, and bottoms of the etched features were determined by x-ray photoelectron spectroscopy (XPS). XPS analyses have shown that when using a Cl-2/N-2 gas mixture, a thin GeNx passivation layer is formed on the sidewalls of the poly-Ge features.