A new drain current model for amorphous IGZO thin film transistors

School of Electronic and Information Engineering, South China University of Technology, Guangzhou 510640, P.R. China

^a e-mail: phrhyao@scut.edu.cn

Received: 19 January 2015
Revised: 3 March 2015
Accepted: 19 March 2015
Published online: 21 April 2015

Abstract

Based on the conduction mechanisms of amorphous InGaZnO (a-IGZO) thin film transistors, generalized equations are derived which permit the determination of drain current characteristics. A geometry-independent definition for field effect mobility considering the ratio of free-to-trapped carriers is introduced, which conveys the properties of the active semiconducting layer. It is suggested that a drain current model that includes different charge transports gives a consistent and accurate description of the electrical behavior. The good agreement between measured and calculated results confirms the efficiency of this model for the design of integrated large-area thin-film circuits.