Oxidation and Sulfidation of Germanium Surfaces: A Comparative Atomic Level Study of Different Passivation Schemes

The effective passivation of germanium surfaces and interfaces has been claimed to be the key to a substantial progress in developing Ge-based microelectronic devices. This paper compares the currently most promising passivation routes, i.e. oxidation and sulfidation, focusing on the underlying atomic scale processes and highlighting similarities and discrepancies between both approaches. The effect of oxidation and sulfidation on electrically active defects is addressed, and the chemical and structural properties of the passivated surfaces are described in detail.