High Performance Si Nanowire TFTs With Ultrahigh on/off Current Ratio and Steep Subthreshold Swing

Abstract

Seeking high drive current, low leakage and swift switching is critical in developing high performance thin film transistors (TFTs) for portable and flexible displays. In this work, we report on the fabrication of high performance TFTs, based on orderly in-plane silicon nanowire (SiNW) array grown at 350 °C, which demonstrate a high ON/ OFF current ratio of $5{\times }{{10}}^{{8}}$ , with a steep subthreshold swing (SS) of 100 mV/dec and a hole mobility of 80 cm2/Vs. The high on current of ${10}~{\mu } {A}$ has been obtained under ${{{0.75} }}{V}$ bias for a channel consisting of only 10 parallel SiNWs, with a mean diameter of ${\sim 66}{\textit {nm}}$ and channel length of ${{2}}~{\mu } {m}$ . In addition, SiNW inverters are also constructed, operating at a drive voltage of 2 V and achieving a gain above 11. These results highlight the geometric advantage of the SiNW TFTs in constructing a new generation of high performance, low cost and scalable display logics and flexible electronics.