| AVS 54th International Symposium | |
| Plasma Science and Technology | Friday Sessions |
| Session PS-FrM |
| Session: | Plasma-Surface Interactions III |
| Presenter: | J.J. An, Massachusetts Institute of Technology |
| Authors: | J.J. An, Massachusetts Institute of Technology H.H. Sawin, Massachusetts Institute of Technology |
| Correspondent: | Click to Email |
In the optimization of PECVD chamber cleaning, it is important to maximize the cleaning rate and minimize the use of gases that are costly and must be treated. It is found that less than 5% of additives such as O2, CO and CO2 in NF3 plasma enhance silicon nitride etching rates particularly at lower temperatures. Using line-of-sight mass spectrometry, we have measured the atomic fluorine density and shown than it is not significantly altered by the additives. While nitric oxide (NO) generated in plasma is considered to be the main contributor of the enhancement of etching rate, its measured levels are small. Besides NO, the role of carbon containing gas products is also taken into account. While the kinetics of this effect are not yet well understood, we will present mass spectrometer results sample by line-of-sight from the plasma source, FTIR measurements of the pump exhaust, as well as etching rate variation with flow rates, pressure and sample temperature.