Unveiling the Influence of Channel Thickness on PBTI and LFN in Sub-10 nm-thick IGZO FETs: A Holistic Perspective for Advancing Oxide Semiconductor Devices

In this work, we present the first systematic and comprehensive investigation into the impact of channel thickness (t
CH
) on the positive bias temperature instability (PBTI) and low frequency noise (LFN) of Indium-Gallium-Zinc-oxide (IGZO) FETs with sub-10 nm t
CH
. A novel Noise-PBTI-Noise (NPN) measuring scheme was proposed that combines LFN and PBTI measurements at different temperatures (T). Our study yields several key findings of significance: (1) FETs with a thinner t
CH
exhibit a higher susceptibility to electron trapping effects while demonstrating greater resilience to the hydrogen (H) effect. (2) Smaller t
CH
values are associated with higher levels of LFN. (3) The mobility fluctuation model (Δµ) effectively describes the LFN characteristics of the FETs, regardless of t
CH
values. Notably, we achieved the record low Hooge's parameter (α
H
) of 2.46×10
^-4
among all amorphous oxide channel transistors. (4) The passivation effect of the H component formed during PBTI on existing traps was identified for the first time. This work highlights the significance of adopting a holistic approach to understanding and optimizing device performance in advancing oxide semiconductor device technology.