Correlation between Light-Induced Degradation and Structural Inhomogeneities in Hydrogenated Amorphous Silicon Prepared under High-Rate Deposition Conditions

The structural inhomogeneities of hydrogenated amorphous silicon (a-Si:H) prepared at high-deposition rates (20–27 Å/s) have been studied by the small angle X-ray scattering (SAXS) technique by changing the rf-electrode (cathode) bias voltages for controlling the ion flux impinging on the growing film surface. The total bonded hydrogen contents of the deposited films are independent of dc-bias, while light-induced degradation is significantly suppressed at the cathode bias V c =+25 V. It is found that structural fluctuation in the range of 10–400 Å as evaluated by SAXS is reduced to about one half at V c =+25 V in comparison with that of conventional deposition conditions at a rate of ∼1 Å/s.