Highly Stable Chip-Scale Tellurium Memtransistor Based on Field-Induced Oxygen Vacancy Migration

Memtransistors have recently attracted attention as promising synaptic devices owing to their precise conductance tunability and heterosynaptic functionality, which can enhance the energy efficiency and integration density of neuromorphic systems. However, previous memtransistors have had difficulty controlling the lateral resistive switching characteristics and reproducibility to achieve a high yield and electrical durability. In this study, highly stable chip-scale Te memtransistor switching based on Schottky barrier height modulation from field-induced oxygen vacancy migration in TeO_2-<i>x</i> was demonstrated. The thickness of the radiofrequency (RF)-sputtered polycrystalline Te is a critical parameter in modulating the resistive behavior with gating tunability because the percentage of TeO_2-<i>x</i> in the Te film can be precisely controlled by its thickness. The Te memtransistor device can emulate heterosynaptic plasticity through voltage stimuli to the drain and gate terminals. The statistical distribution of the synaptic plasticity indicated that 62 devices were functional across an 8 × 8 memtransistor array in a single chip, providing a high yield of >96.9%. Additionally, the device exhibited high linearity and low asymmetry during potentiation/depression endurance cycling over 10 000 pulses. Furthermore, high pattern-recognition accuracy (∼94.2%) for handwritten numbers in a simulation task validated this promising method for the synaptic components of neuromorphic circuits. This study contributes significantly to the design diversity and large-scale integration of neuromorphic systems.