High-rate deposition of hydrogenated amorphous silicon films using inductively coupled silane plasma

Inductively coupled plasma (ICP) generated at 13.56 MHz has been employed for high-rate deposition of device-quality hydrogenated amorphous silicon (a-Si:H). It has been shown that an increase in the flow rate of a monosilane gas enhances the generation rate of deposition precursors, while the ion flux decreases and becomes saturated. The defect density reaches the minimum at a deposition rate of 2.3 nm/s. It has also been demonstrated that even at deposition rates around 4 nm/s, a-Si:H deposited at 150°C exhibits a subgap defect density lower than ∼6×1016 cm−3 after 12 h AM1 (100 mW/cm2) light soaking.