Oxygen vacancy drift controlled three-terminal ReRAM with a reduction in operating gate bias and gate leakage current

Abstract

Three-terminal structures have an advantage over two-terminal structures in logic applications and neuromorphic circuits, However, three-terminal operation based on Valence Change RAM still requires a larger gate bias to form/dissolve a conductive path between the source and the drain, especially for turning off. Here, reduction in gate bias and gate leakage current in nonvolatile operation of oxygen vacancy drift-controlled three-terminal ReRAM is demonstrated by W/Ti (gate)/TaOx (resistance switching layer)/Pt (source), Pt (drain) structure. Introduction of a Ti thin layer between W and TaOx layers prevents a conductive channel formation between gate and source/drain electrodes. Consequently, as-fabricated high resistance between gate and source/drain is kept, resulting in smaller gate leakage current. We also achieved interface engineering on a sidewall structure of Pt (source)/SiO2 (insulator)/Pt (drain) multi-layer, reducing in an operating bias from 10 V to 4 V or less.