Stability of Amorphous-Silicon and Nanocrystalline Silicon Thin-Film Transistors Under DC and AC Stress

Bottom-gated n-channel thin-film transistors (TFTs) were fabricated using hydrogenated amorphous-silicon (a-Si:H)/ nanocrystalline silicon (nc-Si:H) bilayers as channel materials, which are deposited by plasma-enhanced chemical vapor deposition at low temperatures. The stability of these devices is investigated under static and dynamic bias stress conditions. For comparison, the stability of a-Si:H and nc-Si:H single-layer TFTs is investigated under similar bias stress conditions. The overall results demonstrate that the a-Si:H/nc-Si:H bilayer TFTs are superior compared with their counterparts of a-Si:H and nc-Si:H TFTs regarding device performance and stability.