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/f noise in Cu₂O thin-film transistors (TFTs). The static direct current (DC) I-V characterization demonstrates that the channel resistance (R_ch) contributes significantly to mobility degradation in the TFTs, with channel thickness (t_ch) controlled through the plasma-enhanced atomic layer deposition (PEALD) process. The 1/f 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 t_ch, contributed simultaneously. Increased R_ch contributed more significantly to the 1/f noise than to the contact resistance (R_C), as evidenced by the R_C configuration of the measurements, which also revealed that R_C depends upon t_ch. This study demonstrates that t_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.