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

We have investigated the impact of high- k HfO 2 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 SiO 2 and HfO 2 dielectrics. Measured LFNs are nearly 1/ f type for both devices, but the normalized noise for the HfO 2 device is around one order of magnitude higher than that for the SiO 2 device. The bulk mobility fluctuation is considered as the dominant LFN mechanism in both devices, and the increased LFN in the HfO 2 device is attributed to the enhanced mobility fluctuation by the remote phonon scattering from the HfO 2 .