Self-aligned aluminum top-gate polysilicon thin-film transistors fabricated using laser recrystallization and gas-immersion laser doping

We present electrical results from polysilicon thin film transistors (TFT´s) fabricated using laser-recrystallized channels and gas-immersion laser-doped source-drain regions. A simple, four-level self-aligned aluminum top-gate process is developed to demonstrate the effectiveness of these laser processes in producing TFT´s. The source-drain doping process results in source-drain sheet resistances well below 100 /spl Omega///spl square/. TFT field-effect mobilities in excess of 200 cm/sup 2//Vs are measured for the laser-fabricated unhydrogenated TFT´s.