Mitigating Hysteresis in Amorphous Tellurium Selenium Oxide P-Type Field-Effect Transistor Via Fermi-Level Tuning

Abstract

Despite the tremendous progress in n-type oxide semiconductors like InGaZnOx, the development of high-performance p-type oxide semiconductors is indispensable for realizing back-end-of-line-compatible complementary logic in emerging applications such as monolithic three-dimensional integration. While amorphous tellurium selenium oxide (TeSeOx) p-type field-effect transistors (p-FETs) with relatively high mobility exhibit appealing potential, their practical applications remain hindered by pronounced hysteresis and operational instabilities. In this work, we propose a Fermi-level tuning strategy to suppress hysteresis by strategically modulating the energetic alignment between the channel EF and the defect bands within the gate oxide (GOX). Through a comparative analysis of HfO2 and Al2O3 as GOX, we demonstrate that Al2O3 effectively mitigates the instabilities induced by charge trapping. Moreover, despite a lower dielectric constant (κ) of Al2O3 compared to HfO2, Al2O3-gated p-FETs exhibit substantially suppressed hysteresis and enhanced field-effect mobility compared to HfO2-gated counterparts, thereby challenging the conventional capacitance-based scaling expectations.