According to one embodiment, a resistance change device includes a first electrode including a metal, a second electrode, and an amorphous oxide layer including Si and O between the first and second electrode, the layer having a concentration gradient of O and a first peak thereof in a direction from the first electrode to the second electrode. The three-dimensional photonic crystal can include layers containing a plurality of columnar structures with discrete structures in sublayers. The surface inflation tool may, for example, obtain a closed 2D boundary as input, triangulate the area within the boundary to generate an initial surface, and inflate the surface while maintaining a fixed boundary.