A Memristor with Low Switching Current and Voltage for 1S1R Integration and Array Operation

Abstract

© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Memristor devices could realize their full scaling (2D) and stacking (3D) potential if vertically integrated with a two-terminal selector in a one selector one memristor (1S1R) crossbar array. However, for a 1S1R-integrated device to function properly, memristor and selector should be compatible in terms of their material composition and electrical properties. A platinum (Pt)/yttria-stabilized zirconia (YSZ)/zirconium (Zr) memristor with low forming voltage (<1.5 V), low first reset current (150 µA), fast switching speed (2 ns), low voltage (<1 V) and current (50 µA) resistive switching operation, and multi-conductance state capabilities is reported. A low activation energy of oxygen vacancy diffusion (Ea,diffusion = 0.7 eV) measured in the YSZ switching layer enables the proposed memristor to have the observed low-energy operation, which renders it better compatible with a selector device than the more commonly used binary oxides. For a proof-of-principle demonstration, the device is vertically integrated with a tunneling selector and successfully performs memristor-electroforming operations with the selector in a self-compliant 1S1R integrated device. 1S1R cells into a small array (2 × 2) are further investigated and electroforming and resistive switching operations at the array level are demonstrated.