Gallagher Fluid Seals recently added a new white paper to its Resources Page, Perfluoroelastomers for the Semiconductor Industry, written by Russ Schnell. Below is an excerpt from the new white paper discussing plasma process manufacturing. You can download the white paper in its entirety by clicking on the thumbnail to the right.
In plasma process manufacturing, a remote plasma source generates a plasma gas. Note that this type of process is run in a vacuum environment. This gas is composed of ions, electrons, radicals and neutral particles. The flow of these particles must be carefully controlled for etching, deposition, or ashing/stripping processes. These processes often use oxygen, fluorine, and other exotic plasma gases, which are extremely aggressive to many materials. In addition, cleaning processes often use oxygen plasma. Precise control of the plasma gas in the chamber is critical so processes perform as expected, for all the individual chips, across the entire diameter of the wafer.
In the plasma process, which typically operate under a high vacuum, FFKM seals can be critical for maintaining system integrity and providing a long seal life. The term “long seal life” is relative. However these seals must perform at high temperatures, up to 250°C, and still maintain low offgassing and low particle generation to prevent contaminating the manufacturing process. In some cases, under extremely aggressive conditions of plasma gases and high temperatures, 6-8 weeks may be considered a long service life for an elastomer seal.