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 °C) by dc reactive magnetron sputtering. The initial defect state density, determined by the constant photocurrent method, varies from 2–5×1015 cm−3 with H content changing from 15–10 at. % as Ts increases from 320–375 °C. For 100 h of white light exposure at 1 W/cm2, the midgap state density reached an apparent saturation at 2–3×1016 cm−3 over this temperature range. By contrast, films grown at 230–300 °C saturate at 9×1016 cm−3.