a supply of a germanium precursor such as germanium n - butylamidinate is provided in close proximity to a microelectronic device substrate to be contacted therewith for deposition of germanium - containing material on the substrate . specific arrangements are described , including tray and reservoir structures from which solid , liquid , suspended or dissolved germanium precursor can be volatilized for transport to the substrate surface together with other precursors , carrier gases , co - reactants or the like . in such manner , the germanium precursor can be activated independently of the activation of other precursors , within the deposition chamber , to achieve highly efficient formation of germanium - containing material on the substrate , e . g ., a gst film of a phase change memory device .