Effects of CF(4) Plasma Treatment on the Electrical Characteristics of Poly-Silicon TFTs Using a Tb(2)O(3) Gate Dielectric

Abstract

In this paper, we developed high-k Tb(2)O(3) poly-Si thin-film transistors (TFTs) using different CF(4) plasma power treatments. The high-k Tb(2)O(3) poly-Si TFT device with a 20-W plasma power exhibited better electrical characteristics in terms of a highly effective carrier mobility, a high-driving current, a low-threshold voltage, a small subthreshold slope, and a high I(ON)/I(OFF) current ratio. This result is attributed to the incorporation of fluorine atoms into the Tb(2)O(3)/poly-Si interface to reduce the trap-state density. The high-k Tb(2)O(3) poly-Si TFT prepared under a 20-W CF(4) plasma power also enhanced electrical reliabilities, including hot carrier and positive bias temperature instability. All of these results suggest that the CF(4) plasma-treated poly-Si Tb(2)O(3) TFT is a good candidate for high-performance low-temperature poly-Si TFTs.