R. Chatterjee, S. Karecki, R. Reif
Apr 1, 2002
Citations
0
Influential Citations
28
Citations
Journal
Journal of The Electrochemical Society
Abstract
Six unsaturated fluorocarbon (UFC) gases as well as a fluorinated ether were examined for dielectric etch and global warming emissions performance and compared to three perfluorocompound (PFC) gases. All of the gases were capable of etch performance comparable to that of a typical C 3 F 8 process, while exhibiting superior global warming emissions performance compared to the PFCs. A low-flow hexafluoro-2-butyne process was found to have a significant emissions benefit, showing a normalized emissions reduction of 88.2% compared to the C 3 F 8 process. Two other C 4 F 6 isomers (hexafluoro-1,3-butadiene and hexafluorocyclobutene) also exhibited reductions greater than 80%, while hexafluoropropene and octafluorocyclopentene exhibited emissions reductions greater than 70% compared to the typical C 3 F 8 process. For the C 4 F 6 isomers, a large portion of the emissions were a result of CHF 3 formation with photoresist as the sole source of the hydrogen. An extended 4 min etch with hexafluoro-1,3-butadiene resulted in a deep via with an aspect ratio of 5:1, very high selectivity to photoresist, and no evidence of etch stopping.