a low-temperature (600 degrees -750 degrees c) dry surface cleaning process has been developed for in-situ removal of native oxide layers and other surface contaminants. the cleaning process chemistry consists of a mixture of germane (geh/sub 4/) and hydrogen (h/sub 2/) gases with very low germane-to-hydrogen flow ratio (10-20 ppm). the process parameters (e.g. temperature, pressure, and geh/sub 4/'h/sub 2/ gas flow ratio) were adjusted in order to prevent deposition or surface nucleation of germanium during the thermal cleaning process and to minimize the stacking fault densities in the epitaxial silicon layers deposited following the in-situ germane-assisted cleaning steps. the in-situ dry surface cleaning processes developed also include associated geh/sub 4//h/sub 2/-based chemistries with a halogen-containing additive gas such as hcl and/or hf. these surface cleaning processes can be easily integrated with various thin film growth and deposition processes such as epitaxial growth, gate dielectric formation, and polycrystalline or amorphous silicon deposition for mos and bipolar device fabrication