Switching reliability improvement of phase change memory with nanoscale damascene structure by Ge/sub 2/Sb/sub 2/Te/sub 5/ CMP process

Phase change memory with nanoscale damascene structure was successfully fabricated by Ge 2 Sb 2 Te 5 (GST) film chemical mechanical polishing (CMP) process. An ultra-smooth surface reduced the GST/ TiN contact resistance, and more homogeneous GST material composition distribution caused by the damascene structure made GST sheet resistance steady. Thus, switching reliability of the device was improved greatly compared with that of the device without CMP process owing to the reduction of device resistance fluctuation.