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

Published

June 1, 2003

Author(s)

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

Abstract

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

Pub Type

Conferences

Keywords

1, 3 Hexafluorobutadiene, C₄F₆, dielectric etch, etching, plasma

Citation

Nicoletti, A. , Srinivasan, P. , Riva, M. , Benck, E. , Goyette, A. , Wang, Y. , Kim, J. , Hsieh, P. , Athayde, A. and Joshi, A. (2003), C₄F₆ 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 October 9, 2025)