Abstract: A method of forming an oxidation barrier layer in a semiconductor structure includes forming a contact layer on an exposed surface of a semiconductor region of a semiconductor structure in a first processing chamber, wherein the semiconductor region comprises silicon germanium doped with p-type dopants and the contact layer comprises silicon germanium (SiGe) with a ratio of germanium (Ge) ranging between 60% and 100%, and forming an oxidation barrier layer comprising gallium (Ga) on the contact layer, by applying gallium (Ga)-containing liquid precursor to a surface of the contact layer in the first processing chamber.