Patent ID: 8476614

Claim:
A memory device that includes a resistive-change memory element, the memory device comprising: a first memory element that includes a first resistive-change layer, a first resistance-change material supply layer and a first electrode connected to the first resistive-change layer; and a second memory element that includes a second resistive-change layer, a second resistance-change supply layer and a second electrode connected to the second resistive-change layer, wherein, at least one of (a) the thickness of the second resistive-change layer and (b) the area of the second electrode in contact with the second resistive-change layer is different from the corresponding one of (a) the thickness of the first resistive-change layer and (b) the area of the first electrode in contact with the first resistive-change layer, each of the first and second resistive-change layers is made of a material whose resistance changes when an amount of resistance-change material therein from its respective resistance-change supply material layer changes under the influence of a voltage across the resistance-change layer and its respective resistance-change material supply layer, and the first and second memories have different rewrite speeds due to the difference.