Insight into the performance enhancement of double-gated polycrystalline silicon thin-film transistors with ultrathin channel

Abstract

In this letter, characteristics of independently-controllable double-gated polycrystalline silicon (poly-Si) thin-film transistors (TFTs) with ultrathin channel are characterized and analyzed experimentally and theoretically. As compared with the single-gated mode where only one of the gates is used for driving the device, 1.3-2.1 fold increase in drive current is achieved under double-gated mode as the two gates are biased simultaneously for driving the device. A remarkable lowering of barrier height 7-12 meV in the latter case due to the coupling of the two gate biases is identified as the major origin for such performance enhancement.