Low-Frequency Noise Related to the Scattering Effect in p-Type Copper(I) Oxide Thin-Film Transistors

In this study, we investigate the origins of low-frequency noise (LFN) and 1/<i>f</i> noise in Cu₂O thin-film transistors (TFTs). The static direct current (DC) <i>I</i>-<i>V</i> characterization demonstrates that the channel resistance (<i>R</i>_ch) contributes significantly to mobility degradation in the TFTs, with channel thickness (<i>t</i>_ch) controlled through the plasma-enhanced atomic layer deposition (PEALD) process. The 1/<i>f</i> noise followed the Hooge mobility fluctuation (HMF) model, and it was observed that both Coulomb and phonon scattering within the channel, which increased with a decrease in <i>t</i>_ch, contributed simultaneously. Increased <i>R</i>_ch contributed more significantly to the 1/<i>f</i> noise than to the contact resistance (<i>R</i>_C), as evidenced by the <i>R</i>_C configuration of the measurements, which also revealed that <i>R</i>_C depends upon <i>t</i>_ch. This study demonstrates that <i>t</i>_ch is a major noise source in Cu₂O TFTs and presents guidelines for the development of Cu₂O TFTs and potential high-mobility p-type oxide semiconductors.