34.4: Invited Paper: Microcrystalline Silicon: An emerging Material for Stable Thin Film Transistors

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 SiF4‐Ar‐H2 feedstock. In all cases, stable top gate TFT with mobility values around 1 cm2/V.s have been achieved, making them suitable for basic circuit on glass applications. Moreover, the use of SiF4 gas combined with specific treatments of the a‐SiN:H dielectric in bottom gate TFTs, fully compatible with today's a‐Si:H production facilities, lead to an enhancement of the mobility which reaches stable values around 3 cm2/V.s.