Low-Frequency Noise\nRelated to the Scattering Effect\nin p‑Type Copper(I) Oxide Thin-Film Transistors

In this study, we investigate the origins of low-frequency\nnoise\n(LFN) and 1/<i>f</i> noise in Cu<sub>2</sub>O thin-film\ntransistors (TFTs). The static direct current (DC) <i>I</i>–<i>V</i> characterization demonstrates that the\nchannel resistance (<i>R</i><sub>ch</sub>) contributes significantly\nto mobility degradation in the TFTs, with channel thickness (<i>t</i><sub>ch</sub>) controlled through the plasma-enhanced atomic\nlayer deposition (PEALD) process. The 1/<i>f</i> noise followed\nthe Hooge mobility fluctuation (HMF) model, and it was observed that\nboth Coulomb and phonon scattering within the channel, which increased\nwith a decrease in <i>t</i><sub>ch</sub>, contributed simultaneously.\nIncreased <i>R</i><sub>ch</sub> contributed more significantly\nto the 1/<i>f</i> noise than to the contact resistance (<i>R</i><sub>C</sub>), as evidenced by the <i>R</i><sub>C</sub> configuration of the measurements, which also revealed that <i>R</i><sub>C</sub> depends upon <i>t</i><sub>ch</sub>. This study demonstrates that <i>t</i><sub>ch</sub> is\na major noise source in Cu<sub>2</sub>O TFTs and presents guidelines\nfor the development of Cu<sub>2</sub>O TFTs and potential high-mobility\np-type oxide semiconductors.