Formation of microcrystalline-Si thin film transistors by using self-aligned nickel-silicided process

The formation of microcrystalline-Si thin film transistors (μC-Si TFTs) by using self-aligned nickel-silicided process has been studied. The μC-Si TFTs have been generally fabricated as the top-gate staggered-type structure due to the limitation of process temperature up to 200 °C for practical device applications on organic polymer substrates. However, at the processing temperature of 200 °C, this proposed self-aligned nickel-silicided scheme can cause better device characteristics of μC-Si TFTs than the general top-gate staggered structure, without extra photo masking step. As compared to the general top-gate staggered structure, the self-aligned nickel-silicided scheme can lead to larger bending of energy band near the source region, which facilitates causing more carrier tunneling from the source contact electrode. As a result, this proposed self-aligned nickel-silicided scheme can obviously cause a larger on-state current of μC-Si TFTs than the previous top-gate staggered structure.