Enhancement of a Channel Strain via Dry Oxidation of Recessed Source/Drain Si1−xGex Structures

Abstract

We investigated the effects of oxidation on recessed source/drain Si1-xGex structures. Epitaxial Si1-xGex films were deposited on recessed source/drain structures using a selective epitaxial growth process combined with ultrahigh-vacuum chemical vapor deposition and oxidized in dry oxygen ambient. Based on nano beam diffraction analyses, the channel strain was effectively enhanced at specific oxidation conditions. The increase in channel strain results from the formation of Ge-rich layers on the top surface of the Si1-xGex regions upon oxidation.