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Author Cunge, G. ♦ Darnon, M. ♦ Dubois, J. ♦ Bezard, P. ♦ Mourey, O. ♦ Petit-Etienne, C. ♦ Vallier, L. ♦ Despiau-Pujo, E. ♦ Sadeghi, N.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ ASPECT RATIO ♦ DISTRIBUTION ♦ DISTRIBUTION FUNCTIONS ♦ ETCHING ♦ HOLES ♦ ION BEAMS ♦ ION TEMPERATURE ♦ IONS ♦ PLASMA ♦ VELOCITY
Abstract Several issues associated with plasma etching of high aspect ratio structures originate from the ions' bombardment of the sidewalls of the feature. The off normal angle incident ions are primarily due to their temperature at the sheath edge and possibly to charging effects. We have measured the ion velocity distribution function (IVDF) at the wafer surface in an industrial inductively coupled plasma reactor by using multigrid retarding field analyzers (RFA) in front of which we place 400 μm thick capillary plates with holes of 25, 50, and 100 μm diameters. The RFA then probes IVDF at the exit of the holes with Aspect Ratios (AR) of 16, 8, and 4, respectively. The results show that the ion flux dramatically drops with the increase in AR. By comparing the measured IVDF with an analytical model, we concluded that the ion temperature is 0.27 eV in our plasma conditions. The charging effects are also observed and are shown to significantly reduce the ion energy at the bottom of the feature but only with a “minor” effect on the ion flux and the shape of the IVDF.
ISSN 00036951
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-02-29
Publisher Place United States
Journal Applied Physics Letters
Volume Number 108
Issue Number 9


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