Patent ID: 8058702

Claim:
A phase change memory cell, comprising: a first electrode and a second electrode, wherein the first electrode is a single metallic or alloy layer or a metallic compound; a first recording layer disposed between the first and second electrodes; a second recording layer disposed between the first and second electrodes and over the first recording layer; a first heating plug disposed between the first recording layer and the first electrode and contacting the first recording layer; and a second heating plug disposed between the first recording layer and the second recording layer and contacting the second recording layer, wherein: the second heating plug has a total top-view area smaller than a total top-view area of the second recording layer; the first heating plug and the second heating plug allow flowing a programming current through the first recording layer and the second recording layer; and a total contact area between the first heating plug and the first recording layer is smaller than a total contact area between the second heating plug and the second recording layer, wherein the total contact area between the first heating plug and the first recording layer is a portion of a bottom surface of the first recording layer.