Patent ID: 8835895

Claim:
A memory device that includes a resistive-change memory element, the memory device comprising: a first memory element that includes (a) a first resistive-change layer that undergoes changes in resistance, (b) a first electrode connected to the first resistive-change layer, and (c) a first ion source layer that is a source of ions for changing the resistance of the first resistive-change layer; and a second memory element that includes (a) a second resistive-change layer that undergoes changes in resistance, (b) a second electrode connected to the second resistive-change layer, and (c) a second ion source layer that is a source of ions for changing the resistance of the second resistive-change layer, wherein, the first memory element is configured such that the resistance of the first resistive-change layer changes when ions from the first ion source layer diffuse into the first resistive-change layer and when the ions return back to the first ion source layer, the second memory element is configured such that the resistance of the second resistive-change layer changes when ions from the second ion source layer diffuse into the second resistive-change layer and when the ions return back to the second ion source layer, a material of the first resistive-change layer is the same as a material of the second resistive-change layer, the first resistive-change layer is thinner than the second resistive-change layer, and a rewrite speed of the first memory element is faster than a rewrite speed of the second memory element due to the first resistive-change layer being thinner than the second resistive-change layer.