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C4F6 1,3 Hexafluorobutadiene - A New Etching Gas: Studies on Material Compatibility, Behavior in Inductively Coupled Plasma and Etch Processes Performance



A Nicoletti, P Srinivasan, M Riva, Eric C. Benck, A N. Goyette, Yicheng Wang, J M. Kim, P Hsieh, A Athayde, Abhay Joshi


Hexafluoro-1,3-butadiene (C4F6) is a relatively new etch gas for the manufacturing of semiconductor devices, especially in critical etch processes that need high aspect ratios and selectivity. It is able to combine very high performance with a benign environmental effect. This gas has become available on an industrial scale only recently and we felt the need to increase the data in our possession on its behavior both in the plasma chamber and in the gas delivery systems. We report, in this article, the ion energy distributions, relative ion intensities, and absolute total ion current densities measured both for discharge generated in pure C4F^ and in mixture with Argon. In addition, the ratio of radical densities relative to CF measured using sub-millimeter absorption spectroscopy and optical emission spectroscopy measurements are presented for several gas pressures and gas mixture ratios. A comparison with c-C4F8 is made. We report also the material compatibility of this gas, which show how this 'exotic' gas can be handled with standard materials.The most significant benefits of C4F6 gas become evident from its demonstrated performance for a range of increasingly demanding advanced etch processes that require concomitant high selectivity to 193 nm photoresists, hardmasks, and a variety of underlayers while preserving critical dimension and profile control. Advantages of C4F6 based etch processes, such as high aspect ratio contact/via etch, high selectivity mask open, and dual damascene etch processes, developed on an Applied Materials dielectric etcher, and analyses of PFC emissions data are discussed.
Proceedings Title
16th International Symposium on Plasma Chemistry
Conference Dates
June 22-27, 2003
Conference Location
Taormina, 1, IT
Conference Title
International Symposium on Plasma Chemistry


1, 3 Hexafluorobutadiene, C<sub>4</sub>F<sub>6</sub>, dielectric etch, etching, plasma


Nicoletti, A. , Srinivasan, P. , Riva, M. , Benck, E. , Goyette, A. , Wang, Y. , Kim, J. , Hsieh, P. , Athayde, A. and Joshi, A. (2003), C<sub>4</sub>F<sub>6</sub> 1,3 Hexafluorobutadiene - A New Etching Gas: Studies on Material Compatibility, Behavior in Inductively Coupled Plasma and Etch Processes Performance, 16th International Symposium on Plasma Chemistry, Taormina, 1, IT (Accessed April 19, 2024)
Created May 31, 2003, Updated October 12, 2021