Improvement of Electrical Properties and Bias Stability of InGaZnO Thin-Film Transistors by Fluorinated Silicon Nitride Passivation

Abstract

The electrical properties of InGaZnO (IGZO) thin-film transistors (TFTs) with SiOX and fluorinated silicon nitride (SiNX:F) passivation were investigated. The IGZO TFTs with SiNX:F passivation showed excellent performance and positive bias temperature stress (PBTS) stability as compared with those with SiOX passivation after annealing in N2 ambient at 350 °C for 3 hours. Long time annealing could promote fluorine (F) diffusion through an etch stopper layer to an IGZO film. The diffused F could passivate the electron traps, which were the main factor to improve the performance and bias stability of oxide TFTs. The SiNX:F passivation layer will supply F to IGZO channel layer through post-fabrication annealing, which is a novel method for making high performance and stability TFT used in next generation display.