Low heat loss and small contact area composite electrode for a phase change media memory device

The present invention relates generally to a composite electrode including a low heat loss and small contact area interface with a phase change media. More specifically, the present invention relates to a phase change media memory device in which a composite electrode includes an exposed portion in contact with the phase change media. The exposed portion comprises a small percentage of an overall area of the composite electrode such that there is a small area footprint between the exposed portion and the phase change media and the small area footprint reduces heat transfer from the phase change media to the composite electrode. A low heat loss and small contact area electrode structure for a phase change media memory device is disclosed. The memory device includes a composite electrode that includes a dielectric mandrel that is connected with a substrate and having a tapered shape that terminates at a vertex. An electrically conductive material conformally covers the dielectric mandrel and terminates at a tip. A first dielectric layer covers all of the composite electrode except an exposed portion of the composite electrode that is adjacent to the tip. A phase change media is in contact with the exposed portion. The exposed portion is only a small percentage of an overall surface area of the composite electrode so that a contact footprint between the exposed portion and the phase change media is small relative to a surface area of the phase change media and Joule heat transfer from the phase change media into the composite electrode is reduced.