THE IMPROVED STABILITY OF HYDROGENATED AMORPHOUS-SILICON FILMS GROWN BY REACTIVE MAGNETRON SPUTTERING AT HIGH SUBSTRATE-TEMPERATURE

We report the electronic properties, stability, and microstructure of a-Si:H films grown at high substrate temperature (320-440-degrees-C) b y dc reactive magnetron sputtering. The initial defect state density, determined by the constant photocurrent method, varies from 2-5 X 10(1 5) cm-3 with H content changing from 15-10 at. % as T(s) increases fro m 320-375-degrees-C. For 100 h of white light exposure at 1 W/cm2, the midgap state density reached an apparent saturation at 2-3 X 10(16) c m-3 over this temperature range. By contrast, films grown at 230-300-d egrees-C saturate at 9 X 10(16) cm-3.