Low-voltage resistive switching of polycrystalline SrZrO₃: Cr thin films grown on Si substrates by off-axis rf sputtering

A polycrystalline Cr-doped SrZr O3 SrRu O3 layered structure showing a reproducible resistive switching behavior with a resistive switching voltage of ±2.5 V was successfully fabricated on commercial Si (100) substrate by off-axis rf sputtering. Typical resistance values of high- and low-resistance states were about 100 and 5 k, respectively, so that the ratio of high- to low-resistance value is about 20. These values are appropriate for memory applications, and the resistive switching voltage of ±2.5 V is the lowest value among the switching voltages of Cr-doped SrZr O3 films on Si substrates reported in recent literature. We suggest that the low-voltage resistive switching of the polycrystalline Cr-doped SrZr O3 thin film is attributed to the reduction of resputtering effects and the formation of a clean interface between the Cr-doped SrZr O3 thin film and the SrRu O3 bottom electrode layer by the use of 90° off-axis sputtering.