Inverse staggered polycrystalline and amorphous silicon double structure thin film transistors

Inverse staggered polycrystalline silicon (poly-Si) and hydrogenated amorphous silicon (a-Si:H) double structure thin film transistors (TFTs) are fabricated based on the conventional a-Si:H TFT process for the application to liquid crystal display panels with peripheral driver circuits integration. After depositing a thin (20 nm) a-Si:H using the plasma chemical vapor deposition technique at 300 °C, Ar+ and XeCl (300 mJ/cm2) lasers are irradiated on the peripheral driver circuits areas, and then thick a-Si:H (200 nm) and n+Si layers are deposited again. Field effect mobilities of 10 and 0.5 cm2/V s are obtained for the laser annealed poly-Si and the a-Si:H (without annealing) TFTs, respectively.