ELECTRICAL CHARACTERISTICS OF POLY-SI TFTS WITH SMOOTH SURFACE-ROUGHNESS AT OXIDE POLY-SI INTERFACE/

We have fabricated a polycrystalline silicon thin film transistor (pol y-Si TFT) using a novel oxidation method, which improves the surface r oughness at the interface between the poly-Si layer and the gate oxide layer. Compared with the poly-Si TFT's fabricated by the conventional oxidation method, the proposed poly-Si TFT exhibits the remarkable en hancement of the electrical parameters, such as the subthreshold swing and the threshold voltage. It is observed that the proposed poly-Si T FT has a higher dielectric strength, and the device characteristics ar e not degraded significantly after an electrical stress. The improveme nt of the surface roughness at oxide/poly-Si interface is found to be critical to enhance the device performance.