Patent ID: 8188833

Claim:
A variable resistance element comprising: a substrate; a first electrode formed above said substrate; an interlayer insulating layer formed above said substrate; a first variable resistance layer formed on said first electrode in a memory cell hole that is formed to penetrate through said interlayer insulating layer; a second variable resistance layer formed on said first variable resistance layer in the memory cell hole; and a second electrode covering at least a top of the memory cell hole and electrically connected to at least said second variable resistance layer, wherein an electrical resistance value between said first electrode and said second electrode changes in response to application of a predetermined voltage or current between said first electrode and said second electrode, a thickness of said first variable resistance layer at a bottom of the memory cell hole gradually decreases from a center area toward an edge area of the memory cell hole and has a local minimum value around the edge area of the memory cell hole, and an oxygen concentration in said first variable resistance layer is higher than an oxygen concentration in said second variable resistance layer.