Title :
Investigation of instabilities of a-IGZO TFTs under illumination and gate bias stress
Author :
Jie Xu ; Mingxiang Wang ; Dongli Zhang ; Qi Shan
Author_Institution :
Dept. of Microelectron., Soochow Univ., Suzhou, China
Abstract :
Degradation of the transfer characteristics of amorphous In-Ga-Zn-O (a-IGZO) thin film transistors (TFTs) is investigated under visible light illumination (wavelength of 455, 526 and 638nm) and gate bias stress (Vg=±20V, Vd=0). Negative shift of the threshold voltage (Vth) under 455nm illumination is attributed to ionized vacancy creation in a-IGZO film. We find that deep acceptor-like traps are created under NBS, which degrade the subthreshold swing (SS). But the degradation of SS can be suppressed when NBS is combined with 455nm light illumination.
Keywords :
gallium compounds; indium compounds; semiconductor thin films; thin film transistors; zinc compounds; In-Ga-Zn-O; amorphous thin film transistors; deep acceptor-like traps; gate bias stress; subthreshold swing; visible light illumination; voltage 20 V; wavelength 455 nm; wavelength 526 nm; wavelength 638 nm; Logic gates; NIST; IGZO; deep acceptor-like traps; gate bias stress; light illumination; thin film transistors;
Conference_Titel :
Electron Devices and Solid-State Circuits (EDSSC), 2014 IEEE International Conference on
DOI :
10.1109/EDSSC.2014.7061221
