Effects of Parasitic Source/Drain Field Plates on Performances of Channel-Passivated Amorphous InGaZnO Thin-Film Transistors

This paper investigates the effects of parasitic source/drain (S/D) field plates (FPs) on electrical characteristics of channel-passivated amorphous indium gallium zinc oxide thin-film transistors (a-IGZO TFTs). For the S/D metal of the channel-passivated TFT, besides acting as conducting electrodes, they can be FPs to influence the carrier conduction in the semiconductor layer via the channel passivation (CHP) layer. We first fabricated a standard channel-passivated a-IGZO TFT. Based on this TFT, performance variations caused by different lengths of the S/D FPs under different thicknesses of the CHP and a-IGZO layers are explored by technology computer-aided design simulation. Carrier concentration distributions and current flow patterns are examined to study the physical mechanisms of the corresponding performance degradation or improvement.