Impact of High-k HfO2 Dielectric on the Low-Frequency Noise Behaviors in Amorphous InGaZnO Thin Film Transistors

Abstract

We have investigated the impact of high-k HfO2 gate dielectric on the low-frequency noise (LFN) behaviors of amorphous indium–gallium–zinc oxide thin-film transistors by comparing the LFNs of devices with SiO2 and HfO2 dielectrics. Measured LFNs are nearly 1/ f type for both devices, but the normalized noise for the HfO2 device is around one order of magnitude higher than that for the SiO2 device. The bulk mobility fluctuation is considered as the dominant LFN mechanism in both devices, and the increased LFN in the HfO2 device is attributed to the enhanced mobility fluctuation by the remote phonon scattering from the HfO2.