A low-temperature-grown oxide diode as a new switch element for high-density, nonvolatile memories

A working nonvolatile resistance memory cell with an oxide p-n diode is fabricated from p-type NiO_x and n-type TiO_x films grown at low temperatures. A p-n diode si a fundamental circuit element for thin-film electronics, which is fabricated by epitaxial silicon. Oxide based p-n diodes are good candidates to provide solutions to the issues associated with Si-based diodes. The resistance of a Pt/NiO/Pt resistor structure changes with the oxygen content in an argon-oxygen gas mixture, in which the oxygen content is varied from 1 to 30% during deposition of the NiO layer by a reactive sputtering method. This diode structure provides a high rectifying ratio of 10⁵ at ±3 V, useful for various applications including high-density nonvolatile memories with 3D stackable cross-point structures.