Planar magnetron sputtering of a-Si:H and a-Ge:H thin films

Abstract

We have designed and constructed a dual magnetron sputtering system for deposition of amorphous hydrogenated films of silicon (a-Si:H), germanium (a-Ge:H), and alloys of Si and Ge. The system was designed to optimize control of the deposition parameters which may affect film quality. Infrared and Auger electron spectroscopy of films grown in the system show no evidence of contamination by oxygen or carbon within the detection limit of these techniques (∼0.2 at. %). Photoconductivities of the a-Si:H films are comparable to those grown by other techniques. In contrast, the best a-Ge:H films have mobility-lifetime products which are at least an order of magnitude greater than those deposited by other techniques.