Demonstration of bipolar resistive memory fabricated using an ultra-thin BaTiOx resistive switching layer with a thickness of ∼5 nm

Abstract

In this study, a high-performance non-volatile bipolar resistive random-access memory (RRAM), which was fabricated using an ultra-thin barium titanate (BaTiOx, BTO) film as a resistive switching (RS) layer, was demonstrated. The BTO RS layers, whose thicknesses were only about 5 nm, were prepared using radiofrequency sputtering under different oxygen flow rates. Introduction of oxygen was used to modify the chemical compositions of the BTO films. Copper was used as the top electrode material to realize a Cu/BTO/n(+)-Si electrochemical metallization memory, where the resistance switching was triggered by electrochemical reaction of Cu electrode. The RRAM could repeatedly and consistently switch between a high-resistance state and a lowresistance state over 300 cycles. A large memory window of 10(5) and a long data retention time of >1.5 x 10(4) s both at room temperature and 85 degrees C were observed. Moreover, the Cu/BTO/n(+)-Si RRAM showed high switching speeds of 60-70 ns.