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 Angstrom/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 fur impinging on the growing film surface. The total bonded hydrogen contents of the deposited films are independent of de-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 Angstrom as evaluated by SAXS is reduced to about one half at V-c = +25 V in comparison with that of conventional deposition conditions ata rate of similar to 1 Angstrom/s.