Patent ID: 8766226

Claim:
A non-volatile semiconductor storage device comprising: a first line; a second line that intersects the first line; and a memory cell arranged at a position where the first line and the second line intersect, wherein the memory cell includes a resistance change layer, an upper electrode layer arranged above the resistance change layer, a lower electrode layer arranged below the resistance change layer, a diode layer arranged above the upper electrode layer or below the lower electrode layer, a first oxide film existing on a side wall of at least one electrode layer of the upper electrode layer or the lower electrode layer, a second oxide film existing on a side wall of the diode layer, and a protective film to cover the side wall of the at least one electrode layer and the first oxide film; and wherein a film thickness of the first oxide film is thicker than a film thickness of the second oxide film, the diode layer is arranged below the lower electrode layer, and the protective film further covers the side wall of the diode layer and the second oxide film.