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

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. [ABSTRACT FROM AUTHOR]