Nanotech West has completed the installation of, and initial process development for, a refurbished Plasma Therm 790 plasma-enhanced chemical vapor deposition (PECVD) tool. The tool has been installed in Bay 3 of the cleanroom facility and is open for immediate user training and use; contact Pete Janney. The tool code for the 790 is CVD02.
The 13.56 MHz frequency tool has a 200 mm circular platen that can accommodate a wide range of sizes of parts. Our initial recipes for the tool include deposition of silicon nitride (from ammonia and 2% silane in He, with N2 used as a ballast gas) and silicon oxide (from nitrous oxide and also 2% silane in He, also with N2), both at 250o C. We developed these processes using refractive index, obtained with spectroscopic ellipsometry, as our primary measurement of thin film stoichiometry (targets n ~1.46 for oxide, ~2.0 for nitride). We fully expect that our users will develop their own processes for the tool and help us improve the initial processes in many ways.
The Nanotech West staff would like to thank our friends at the University of California at Santa Barbara Nanotech, who own a nearly identical tool and who generously supplied some initial recipes to us. Their help greatly reduced the amount of time it took for us to develop the initial silicon nitride and silicon oxide recipes, and we hope to be able to return a favor someday.
Bob Davis, Ph.D.
Director, Ohio State Nanotech West Lab