Patent ID: 8854864

Claim:
A variable resistance nonvolatile memory element comprising: a first electrode; a second electrode; and a variable resistance layer which comprises a metal oxide positioned between the first electrode and the second electrode, the metal oxide having a resistance state that reversibly changes between a high resistance state and a low resistance state according to a polarity of a voltage pulse applied between the first electrode and the second electrode, wherein the variable resistance layer includes: a first metal oxide layer which is positioned on the first electrode, and has a resistivity ρ x and a composition that is expressed by MO X where M represents a metal element; a second metal oxide layer which is positioned on the first metal oxide layer, and has a resistivity ρ y where ρ x <ρ y and a composition expressed by NO y where N represents a metal element; a third metal oxide layer which is positioned on the second metal oxide layer, and has a resistivity ρ z where ρ y <ρ z and a composition expressed by PO z where P represents a metal element; and a localized region which is positioned in the third metal oxide layer and the second metal oxide layer to be in contact with the second electrode and not to be in contact with the first metal oxide layer, and has a resistivity that is lower than the resistivity of the third metal oxide layer and different from the resistivity of the second metal oxide layer.