International Business Machines Corporation
Phase change memory using multiple stacks of PCM materials

Abstract:

A method is presented for improved linearity of a phase change memory (PCM) cell structure. The method includes forming a bottom electrode over a substrate, constructing a PCM stack including a plurality of PCM layers each having a different crystallization temperature over the bottom electrode, and forming a top electrode over the PCM stack. The crystallization temperature varies in an ascending order from the bottom electrode to the top electrode.