PREPARATION OF HYDROGENATED AMORPHOUS-GERMANIUM BY REACTIVE THERMAL EVAPORATION

Hydrogenated amorphous germanium was prepared by the thermal evaporation of high purity polycrystalline germanium in an atmosphere of hydrogen plasma produced by high voltage ac discharge of molecular hydrogen. The addition of hydrogen during the thermal evaporation of germanium is shown to improve the electrical properties of the resulting amorphous germanium films considerably by saturation of dangling bonds, if the dissociation of molecular hydrogen takes place. A hydrogenated sample deposited at 200 degree C has shown a high resistivity and an activation type conduction (with an activation energy of 0. 38-0. 39 ev) in measuring temperature range (above room temperature).