MATLAB-BASED DC COMPACT MODELING AND OPTIMISATION OF ULTRA-LOW VOLTAGE IGZO TFTs

Abstract

The potential future of electronic applications such as the Internet of things (IoT) and sensors requires low operating voltage designs. To achieve this, low voltage thin film transistors or TFTs are needed. Additionally, modelling and simulation are essential tools to predict the performance of a TFT before its fabrication. Furthermore, DC compact modelling is an important approach to simulate TFT devices. This dissertation aims to develop a DC compact model for ultra-low voltage indium gallium zinc oxide TFTs using the MATLAB software. This research consists of three parts: building an understanding of the physics behind TFTs and modelling approaches and adopting a proper DC compact model from the literature, extracting the required chosen parameters, and developing the chosen model using optimisation techniques. Two proposed DC compact models with a few empirical parameters were developed from an adopted universal compact model for TFTs available in the literature to simulate ultra-low voltage IGZO TFTs with high accuracy. The Nelder-Mead optimisation algorithm was implemented to extract and optimise the unknown variables. The proposed models were verified on a second device fabricated using the same materials and structures and showed good reliability and capability.