Deep-Level Trap Engineering in Sn-Doped β-Ga2O3 MISFETs for Optoelectronic Memory and Reconfigurable Logic Application

Abstract

Nonvolatile memory platforms that avoid conventional floating-gated charge-storage layers are attracting increasing interest for next-generation data-centric electronic systems. In this work, we present a Sn-doped β-gallium oxide (β-Ga₂O₃) metal–insulator–semiconductor field-effect transistor (MISFET)-based optoelectronic memory (OEM) device that utilizes intrinsic deep-level trap states in the β-Ga₂O₃ channel as nonvolatile charge storage sites. The β-Ga₂O₃ OEM device exhibits stable transistor operation with a high drain current on/off ratio (>10⁵) and a near-ideal subthreshold slope (60 mV/dec). In addition, programmable threshold voltage (V_th) modulation is achieved through electrical erasing (EE) and optical programming (OP) processes, resulting in a wide memory window of 4.2 V by applying an EE pulse of 4 V and an OP pulse under 405 nm deep blue illumination. The optically and electrically defined memory states show stable memory retention (>10³ s) and memory endurance (>10³ cycles). Furthermore, we integrate the OEM device into a resistive-load inverter circuit to demonstrate memory-state-dependent logic operation. By modulating the memory state, the same circuit can be reconfigured between a conventional inverter mode and an input-independent logic mode. These results highlight the potential of the β-Ga₂O₃ OEM as a scalable platform for next-generation nonvolatile memory technologies.