In SituHydrogenation of Amorphous Silicon Prepared by Thermal Decomposition of Disilane

Thin hydrogenated amorphous silicon (a-Si:H) layers with thicknesses of 90-600 Å grown by thermal decomposition of disilane were treated with rf hydrogen plasma just after deposition at the same temperature (430-440°C). During this process (referred to as in situhydrogenation), atomic hydrogen passivates defects, and the effective thickness of this passivated layer is estimated to be 220 Å. Atomic hydrogen also induces structural relaxation of the Si network even in a-Si:H deposited at high temperature (>400°C) while the change of bonded hydrogen content is rather small in in situhydrogenation.