Effects of $\hbox{CF}_{4}$ Plasma Treatment on the Electrical Characteristics of Poly-Silicon TFTs Using a $ \hbox{Tb}_{2}\hbox{O}_{3}$ Gate Dielectric

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.