Patent ID: 8125021

Claim:
A non-volatile memory device, comprising: a lower electrode; a single, first oxide layer including ruthenium (Ru) oxide or zinc (Zn) oxide directly formed on the lower electrode; a single, second oxide layer including nickel (Ni) oxide for ohmic contact directly formed on the first oxide layer, and having variable resistance characteristics; a buffer layer including a p-type oxide for ohmic contact formed on the second oxide layer, wherein a first ohmic contact is formed at an interface between the second oxide layer and the buffer layer; and an upper electrode formed on the buffer layer, wherein a second ohmic contact is formed at an interface between the buffer layer and the upper electrode, wherein the buffer layer includes at least one material selected from NiO (1+x) (wherein 0<x<1) and Cu deficient Cu oxide, and the upper electrode is composed of a metal having a work function lower than that of a noble metal.