a-IGZO TFT Simulation

1. Introduction

The flat panel device for active matrix liquid crystal displays (AMLCDs) and active matrix organic light-emitting diode displays (AMOLEDs) has utilized a low cost amorphous silicon or low temperature poly-silicon (LTPS) as a fast switching transistor in mobile devices,TVs, and other display consumer electronics. Recently, amorphous InGaZnO (a-IGZO) thin-film transistor (TFT) is now one of the most important materials in the display area for flexibility, large-area uniformity and high mobility. The conventional a-Si:H TFT or LTPS devices have many degradation problems such as bias stress and photo induced instabilities that are the most important factors which must be fully understood and analyzed to improve the device design. These instabilities come from time-dependent density of states (DOS) change in forbidden band gap of material during device operation.

This article aims to make a real DOS shape in Atlas device simulation software from experimentally extracted DOS and to reproduce the reference data. From this DOS, we can simulate a-IGZO TFT more correctly and this is the basic start point of further analyzing device instabilities.