Electrical Evolution of p-Type SnO x Film and Transistor Deposited by RF Magnetron Sputtering

作者：Yuyan Zhou, Yu Song, Ruohao Hong, Xingqiang Liu, Xuming Zou, Benjamı́n Iñı́guez, Denis Flandre, Guoli Li, Lei Liao · 发表于：IEEE Transactions on Electron Devices · 年份：2023 · DOI：10.1109/ted.2023.3266417 · 被引用次数：11 · 研究领域：ZnO doping and properties、Semiconductor materials and devices、Thin-Film Transistor Technologies

In this work, by altering oxygen partial pressure (OPP) and sputtering power (${P}_{\text {RF}}$) of the radio frequency (RF) magnetron sputtering process, we investigate electrical evolution of the p-type SnOx film and transistor. Herein, combining device current–voltage (such as ON-state current and field-effect mobility), low-frequency noise (LFN), and gate-bias-stress characteristics, we find that the optimal OPP range is 4.8%–7.2% for the SnOx film deposition at${P}_{\text {RF}}$of 70 and 30 W. Based on X-ray photoelectron spectroscopy (XPS), the SnOx films deposited at high power (70 W) show less sensitivity to OPP, which leads to the slow transition of internal Sn2+, Sn4+ states, and a relatively large process window. Furthermore, the defect states inside the SnOx are analyzed. The oxygen interstitials (Oi), as deep acceptors, keep inactive regardless of the external bias. The oxygen vacancies (Vo) and the ionized Vo2+ states, which act as the electron traps, get suppressed and are attributed to the ambipolar behavior in the SnOx transistor, while increasing the OPP. This work benefit lies in a comprehensive analysis of the sputtering process parameters impact on SnOx film and transistor properties and their underlying defects.