Realization of forming-free ZnO-based resistive switching memory by controlling film thickness

Abstract

Cu/ZnO/n + -Si structures that show resistive switching behaviour have been successfully fabricated. The influence of ZnO thickness on resistive switching is investigated. As the ZnO thickness is reduced from 100 to 25 nm, Cu/ZnO/n + -Si cells change from forming-necessary ones to forming-free ones. Compared with the forming-necessary cells, the forming-free cells show more stable resistive switching characteristics. The underlying mechanism of the forming-free phenomenon is proposed. We infer that the oxygen vacancies pre-existing in ZnO films play an important role in the realization of forming-free cells.