Low Temperature Plasma Deposited Microcrystalline Silicon Thin Films. An Emerging Material for Stable Thin Film Transistors

摘要

Top gate and bottom gate microcrystalline silicon thin film transistors (TFTs) have been produced by the radio frequency glow discharge technique using three preparation methods: the standard hydrogen dilution of silane in hydrogen, the use of the layer-by-layer technique, and the use of SiF_4-Ar-H_2 feedstock. In all cases, stable top gate TFT with mobility values around 1 cm~2/V.s have been achieved, making them suitable for circuit on glass applications. Moreover, the use of SiF_4 gas combined with specific treatments of the a-SiN:H dielectric in bottom gate TFTs, fully compatible with today's a-Si:H process, lead to lateral growth of the silicon crystallites and an enhancement of the mobility to reache stable values of around 3 cm~2/V.s.