High-performance laser-processed polysilicon thin-film transistors

We present electrical results from hydrogenated laser-processed polysilicon thin-film transistors (TFT's) fabricated using a simple four-mask self-aligned aluminum top-gate process. Transistor field-effect mobilities of 280-450 cm/sup 2//Vs and on/off current ratios of more than 10/sup 8/ are measured in these devices. Except for the amorphous-silicon deposition step, the highest processing temperature that the substrate was subjected to was 350/spl deg/C. Such good performance is attributed to an optimized laser-crystallization process combined with hydrogenation.