Laser Photochemical Production of Germanium and Doped-Germanium Films.

Germanium and doped-germanium polycrystalline films have been formed using CO2 laser photochemistry. The compounds which were found to be the best candidates for the production of germanium were germane, ethylgermane and diethylgermane. The gas phase reactions were monitored using fourier transform infrared spectroscopy, also used for identification of end products. Scanning electron microscopy was used for analysis of the films. The products identified on irradiation of germane were germanium and hydrogen. Conversion rates on the order of 86% were observe, indicating possible cost savings over thermal processes. On irradiation, both diethylgermane and ethylgermane produce ethylene, germane, germanium and hydrogen. Germanium containing cadmium and aluminum was successfully produced by the irradiation of germane mixtures containing dimethylcadmium or trimethylaluminum respectively. (Author)