Patent ID: 8179713
Filing Date: 2012-05-15
Classification: G11C,H01L

Abstract:
1. A nonvolatile memory element comprising: a first electrode; a second electrode; and a resistance variable layer which is provided between the first electrode and the second electrode, and is configured to reversibly switch an interelectrode resistance value which is a resistance value between the first electrode and the second electrode, in response to an interelectrode voltage which is an electric potential of the second electrode on the basis of the first electrode; wherein the resistance variable layer includes an oxygen-deficient transition metal oxide; wherein the first electrode side and the second electrode side have an asymmetric structure; and wherein a portion of the resistance variable layer which is located at the first electrode side and a portion of the resistance variable layer which is located at the second electrode side are each configured to be selectively placed into one of a low-resistance state and a high-resistance state, so as to attain a stable state in three or more different interelectrode resistance values, the stable state being a state in which the interelectrode resistance value is invariable regardless of a change in the interelectrode voltage within a specified range.