Patent ID: 8729517

Claim:
A nonvolatile semiconductor memory device comprising: a first interconnect extending in a first direction on a major surface of a substrate; a second interconnect extending in a second direction non-parallel to the first direction; and a resistance change layer including a conductive nanomaterial, the resistance change layer located between the first interconnect and the second interconnect and being capable of reversibly changing between a first resistance state and a second resistance state by a voltage applied or a current supplied through the first interconnect and the second interconnect, the resistance change layer having a density of the conductive nanomaterial varied along a third direction generally perpendicular to the first direction and the second direction, the resistance change layer having a first end portion on a side of the substrate in the third direction and a second end portion opposite from the first end portion, and the density of the conductive nanomaterial on a side of the second end portion being higher than the density of the conductive nanomaterial of a central portion in the third direction.