Advanced Process and Structure for High Performance Oxide Thin‐Film Transistors

Abstract

The required carrier mobility of metal oxide thin‐film transistors (TFTs) has been increasing rapidly to meet the demands of the ultra‐high‐resolution, large panel size and three dimensional visual effects as a megatrend of flat panel display. However, the typical field‐effect mobility of IGZO TFTs in the practical production line is less than 10 cm2/Vs, which is still not enough to drive the high‐end flat panel displays with ≥ 300 ppi, more than 60 inch and high frame rate ( ≥ 240 Hz). Approaches to improve the mobility of electron carriers in metal oxide TFT would involve the optimization of cation composition, stacked channel structure and the lattice ordering‐induced crystallization. In this paper, we presented our recent efforts toward the high performance and good reliability, which included the non‐IGZO composition, double channel structure such as ZTO/IZO and ZTO/ITO, the metal‐induced crystallization at a low temperature, and atomic layer deposited IGZO TFTs.