Electrode for phase change memory device

摘要

A memory device (10) includes a composite electrode (12) that includes a dielectric mandrel (13) that is connected with a substrate (11) and having a tapered shape that terminates at a vertex (V). An electrically conductive material (15) conformally covers the dielectric mandrel (13) and terminates at a tip (T). A first dielectric layer (17) covers all of the composite electrode (12) except an exposed portion (E) of the composite electrode (12) that is adjacent to the tip (T). A phase change media (19) is in contact with the exposed portion (E). The exposed portion (E) is only a small percentage of an overall surface area of the composite electrode (12) so that a contact footprint (Ac) between the exposed portion (E) and the phase change media (19) is small relative to a surface area (AM) of the phase change media (19) and Joule heat (jh) transfer from the phase change media (19) into the composite electrode (12) is reduced. <IMAGE>