Storage device

A storage device comprising:

• a plurality of row lines arranged parallel to one another;
• a plurality of column lines arranged parallel to one another to intersect with the row lines;
• and
• a memory cell which is disposed at each of intersections of the row lines and the column lines and which comprises a resistance-change element and a diode connected in series to the resistance-change element through an electrode attached to the resistance-change element, the diode comprising a stack of a first semiconductor region containing an impurity of a first conductivity type, a second semiconductor region containing an impurity of the first conductivity type lower in concentration than in the first semiconductor region, and a third semiconductor region containing an impurity of a second conductivity type,
• wherein an impurity concentration in the second semiconductor region of the diode in a first adjacent portion adjacent to the first semiconductor region is higher than that in a second adjacent portion adjacent to the third semiconductor region, and
• wherein the resistance-change element includes one of substances selected from the group consisting of ZnMn2O4, NiO, TiO2, SrZrO3, and Pr0.7Ca0.3MnO3, and the electrode includes one of substances selected from the group consisting of TiN, Pt, W, WN, TaN, and Nb-doped TiO2.