Kazuhiro Ogawa

Inverse staggered poly-Si and amorphous Si double structure TFT's for LCD panels with peripheral driver circuits integration

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 on a single glass substrate. After depositing a thin (20 nm) a-Si:H using the plasma CVD technique at 300/spl deg/C, Ar/sup +/ and XeCl (300 mJ/cm/sup 2/) lasers are irradiated successively, and then a thick a-Si:H (200 nm) and n/sup +/ Si layers are deposited again. The field effect mobilities of 10 and 0.5 cm /sup 2//V/spl middot/s are obtained for the laser annealed poly-Si and the a-Si:H (without annealing) TFTs, respectively.

An LCD addressed by a-Si:H TFTs with peripheral poly-Si TFT circuits

Poly-Si TFTs of an inverted staggered structure are fabricated by peripheral laser annealing of plasma CVD a-Si:H films on SiN gate insulator. The side contact structure improves the TFT characteristics resulting in mobility of 20 cm/sup 2Vs and on/off ratio of 10/sup 6/. The fabrication process, carried out below 300/spl deg/C, is compatible with conventional a-Si TFT processes. The LCD using a switch matrix of poly Si TFTs has good performance and reduces the number of driver ICs by half.<<ETX>>

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.