Patent ID: 7767994
Filing Date: 2010-08-03
Classification: H01L

Abstract:
1. A Phase-change Random Access Memory (PRAM) device comprising: a lower electrode formed over a semiconductor substrate; an upper electrode formed over the lower electrode; a phase change material layer disposed between the lower electrode and the upper electrode, and a heating layer disposed between the upper electrode or the lower electrode and the phase change material layer, wherein the heating layer comprises a first heating layer and a second heating layer, the first heating layer contacting the phase change material layer and the second heating layer contacting the first heating layer and being disposed between the first heating layer and the upper electrode or the lower electrode, wherein the first heating layer comprises a material having lower resistivity than the resistivity of a material forming the second heating layer, and wherein the second heating layer comprises polysilicon (poly Si) or polysilicon germanium (poly-SiGe).