Patent ID: 7956344
Filing Date: 2011-06-07
Classification: H01L

Abstract:
1. A memory cell of the type including a memory material switchable between electrical property states by the application of energy, the memory cell comprising: a substrate with a contact for an access circuit; an electrically conductive plug extending through an interlayer dielectric within the substrate to the contact; a ring-shaped bottom electrode comprising a first, ring-shaped lower part having a first contact area with a first lateral dimension in contact with the plug, and a second, upper part, the second, upper part having a generally ring-shaped upper end surrounding a non-conductive central region, the ring-shaped upper end with a second contact area between an inside perimeter and an outside perimeter of the ring-shaped upper end, the outside perimeter having a second lateral dimension; the first lateral dimension being longer than the second lateral dimension; the lower part being a non-perforated structure; a top electrode; and a memory element comprising a memory material switchable between electrical property states by the application of energy, the memory element positioned between and in electrical contact with the top electrode and the second contact area on the ring-shaped upper end of the second part of the bottom electrode.