Patent ID: 8054674

Claim:
A variable resistive element comprising: a metal oxide layer between a first electrode and a second electrode where an electrical resistance between the first and second electrodes reversibly changes in accordance with application of an electrical stress across the first and second electrodes, wherein the metal oxide layer has a filament which is a current path where a density of a current flowing between the first and second electrodes is locally high, a portion including at least a vicinity of an interface between a certain electrode, which is one or both of the first and second electrodes, and the filament, on an interface between the certain electrode and the metal oxide layer is provided with an interface oxide which is an oxide of a certain element and different from an oxide of the metal oxide layer, the certain element being at least one element included in the certain electrode, and the variable resistive element further comprising a current narrow portion where the current path of the filament is narrowed by the interface oxide in a vicinity of a contact point between the filament and the interface oxide.