Abstract—Reducing the OFF-state leakage current, and eliminating the pseudo-subthreshold conduction in polysilicon thin-ﬁlm transistors (TFTs), is a major problem since the channel current is controlled by the potential barrier associated with the grain boundaries in the undoped channel. In this paper, we present for the time, a new gate-induced barrier TFT (GIB-TFT) in which the undoped channel has no grain boundaries, while the channel current is controlled by inducing large potential barriers in the channel. We demonstrate that the proposed GIB-TFT exhibits a steep subthreshold slope and at least three orders of magnitude less OFFstate leakage current when compared to the conventional polysilicon TFTs. Using two- dimensional and two-carrier device simulation, we have analyzed the various performance and design considerations of the GIB-TFT and explained the reasons for its improved performance.
Index Terms—Grain boundary, leakage current, polysilicon, potential barrier, subthreshold, thin-ﬁlm transistor (TFT), traps, two-dimensional (2- D) simulation.
The above paper can be downloaded from http://web.iitd.ac.in/~mamidala/id11.htm