Electrical characteristics of a bendable a-Si:H thin film transistor with overlapped gate and source/drain regions

Abstract

In this study, we investigate the influence of an overlap between the gate and source/drain regions of a-Si:H thin film transistors (TFTs) on their electrical characteristics under tensile or compressive strain through experiment and mechanical simulation. The strain distribution in the a-Si: H TFT for a bending radius of 2mm reveals that the strain at both ends of the TFT is ten times larger than that at the source-drain current path. The overlap lowers the stress sustained by the TFT in the region comprised between the channel and the gate insulator; therefore, TFTs with the overlap operate even at a tensile strain of 2.54%. In particular, the overlap is remarkably effective on relaxing the stress sustained in the interface between the gate insulator and the gate electrode, consequently improving the electrical stability of the bent TFT. Published by AIP Publishing.