Modeling of current—voltage characteristics for double‐gate a‐IGZO TFTs and its application to AMLCDs

Abstract

Abstract— The equations for the transfer characteristics, subthreshold swing, and saturation voltage of double‐gate (DG) a‐IGZO TFTs, when the top‐ and bottom‐gate electrodes are connected together (synchronized), were developed. From these equations, it is found thatsynchronized DG a‐IGZO TFTs can be considered as conventional TFTs with a modified gate capacitance and threshold voltage. The developed models were compared with the top or bottom gate only bias conditions. The validity of the models is discussed by using the extracted TFT parameters for DG coplanar homojunction TFTs. Lastly, the new pixel circuit and layout based on a synchronized DG a‐IGZO TFT is introduced.