Self-align planerized bottom electrode phase change memory and manufacturing method

摘要

A method is described for self-aligning a bottom electrode in a phase change random access memory PCRAM device where a top electrode serves as a mask for self-aligning etching of the bottom electrode. The bottom electrode has a top surface that is planarized by chemical mechanical polishing. The top electrode also has a top surface that is planarized by chemical mechanical polishing. A bottom electrode layer like TiN is formed over a substrate and prior to the formation of a via during subsequent process steps. A first dielectric layer is formed over the bottom electrode layer, and a second dielectric layer is formed over the first dielectric layer. A via is formed at a selected section that extends through the first and second dielectric layers.