High-performance thin-film transistors using Ni silicide for liquid-crystal displays

The Ni-silicide of a sheet resistance of 7 Ω/□ can be formed at 230 °C on n⁺ a-Si:H and thus can be applied to gate and source/drain contacts for high performance TFTs. Because of its low resistance it is possible to make a self-alignment between gate and source/drain, which lead to a coplanar a-Si:H TFT having a low parasitic capacitance between them. The NiSi₂ precipitates can be formed on a-Si:H at around 350 °C and needlelike Si crystallites are grown as a result of the migration of the NiSi₂ precipitates though a-Si:H network. Amorphous silicon can be crystallized at 500 °C in 10 minutes in a modest electric field. The low temperature poly-Si TFT with a field effect mobility of 120 cm²/Vs has been demonstrated using the low temperature poly-Si.