GERMANIUM THIN-FILM FORMATION BY LOW-PRESSURE CHEMICAL-VAPOR-DEPOSITION

Thin films of polycrystalline germanium were formed by the pyrolysis o f germane gas in a low-pressure reactor. Process parameters investigat ed were deposition temperature in the range 250 to 350 degrees C and p ressure in the range 300 to 600 mTorr. The properties of the film have been characterized using transmission electron microscopy and x-ray d iffraction for structural analysis, atomic force microscopy for surfac e morphology analysis, secondary ion mass spectroscopy for composition al analysis, and Hall effect measurement for electrical parameter extr action, etc. High Hall effect mobility on the order of 300 cm(2)/V s w as obtained, even at a relatively low deposition temperature of 300 de grees. This makes the germanium thin films potentially very promising for low-temperature device processing.