A New RSD Poly-Si Thin Film Transistor With Inside Spacer Design

In this brief, a raised source/drain, accompanied with an inside spacer poly-Si thin film transistor (RSDIS-TFT) structure, has been proposed and discussed. The gate covered on an inside spacer can serve as a field plate and create a field-induced drain region to reduce the channel electric field. The proposed device has a lower drain electric field and can alleviate the kink effect. In addition, the leakage current can also be reduced. This is because this RSDIS structure can spread the electric field intensity out at the end of the drain, and decrease the drain electric field. Moreover, the device stability, such as the threshold voltage shift and transconductance degradation under a high gate bias, is improved by the design of raised source/drain and inside spacer structure. The lower drain electric field of the RSDIS-TFT is also beneficial to scaling down the device for a better performance. Therefore, the proposed poly-Si TFT is suitable to be used in active-matrix flat panel electronics.