A High-Performance Polysilicon Thin-Film Transistor Built on a Trenched Body

In this paper, a high-performance polysilicon thin-film transistor (poly-Si TFT) with a trenched body is proposed, fabricated, and studied. This new trenched TFT can be easily produced by filling and etch-back technology without destroying the channel film quality. The addition of the body trench is found to reduce the off-state leakage current by 70% on average, because the trench induces a carrier scattering effect in the poly-Si grain-boundary traps, thereby affecting the leakage path. Although the off-state current is substantially reduced, the on-state current is comparable with that of a conventional TFT. Our multiple-trenched-body TFT is also shown to improve the breakdown voltage by 11%.