Off-state current reduction in NbO2-based selector device by using TiO2 tunneling barrier as an oxygen scavenger

Abstract

We report a significant off-state current reduction by an order of magnitude in the NbO2-based selector devices by inserting an ultrathin TiO2 (similar to 2 nm) tunneling barrier. Moreover, the ultrathin TiO2 layer improves the reliability and uniformity of voltage-induced insulator-to-metal transition (IMT) in the NbO2 selector devices by thermodynamically suppressing the formation of a surface Nb2O5 layer. Our study suggests that the suitable combination of tunneling barrier and IMT materials can minimize the "off" current of IMT selector devices and improve their applicability in high-density three dimensional cross point array memory devices. Published by AIP Publishing.