Wednesday, August 12, 2009

US Patent 7572662 - Fullerene phase change RAM

This patent from Samsung teaches using fullerene to improve the electrical characteristics of electrode contacts in phase change memory. Claim 1 reads:

1. A method of fabricating a phase change RAM (PRAM) comprising:

forming a bottom electrode, forming an interlayer dielectric film covering the bottom electrode, and forming a bottom electrode contact hole exposing a portion of the bottom electrode in the interlayer dielectric film;

forming a bottom electrode contact plug by filling the bottom electrode contact hole with a plug material;

forming a fullerene layer on a region including at least an upper surface of the bottom electrode contact plug; and

sequentially stacking a phase change layer and an upper electrode on the fullerene layer, wherein the fullerene layer contacts the bottom electrode contact plug.