Thin film transistors fabricated with poly-Si films crystallized by microwave annealing

Solid phase crystallization has the advantages of low cost and excellent un iformity but the crystallization temperature is too high to use glass as a substrate. Using microwave annealing, we crystallized a-Si films at 550 deg rees C within 3h, which is much shorter than the annealing time at 600 degr ees C of furnace annealing. We fabricated TFTs with poly-Si films crystalli zed by microwave annealing at low temperature and obtained the characterist ics to be slightly better than or at least comparable to the TFTs by furnac e annealing in spite of smaller grain size. This may have been due to the i mprovement of surface roughness of poly-Si film. The poly-Si TFTs with PECV D a-Si film showed better characteristics than the TFTs with LPCVD a-Si fil m because of larger grain size and smoother Si/SiO2 interface.