Journal of the Korean Physical Society

pISSN 0374-4884 eISSN 1976-8524


Particles and Nuclei

J. Korean Phy. Soc. 2011; 59(5): 3024-3030

Published online November 15, 2011

Copyright © The Korean Physical Society.

Characteristics of SiO2 Etching with a C4F8/Ar/CHF3/O2 Gas Mixture in 60-MHz/2-MHz Dual-frequency Capacitive Coupled Plasmas

M. H. Jeon, S-K. Kang, J. Y. Park, G. Y. Yeom


nanoscale SiO2 contact holes were etched by using C4F8/CHF3/O2/Ar gas mixtures in dual-frequency capacitive coupled plasmas (DF-CCPs) where 60 MHz source power is applied to the top electrode while 2 MHz bias power is applied to the bottom electrode. The initial increase of CHF3 gas flow rate at a fixed CHF3+O2 flow rate increased the SiO2 etch rate in addition to the increase of SiO2 etch selectivity over ACL. When the HF power was increased, both SiO2 etch rate and the etch selectivity over ACL were increased with the increase of HF power. At the 300W/500W of 60MHz HF power/ 2MHz LF power ratio and the gas mixture of Ar (140 sccm) /C4F8 (30 sccm) /CHF3 (25 sccm) /O2 (5 sccm) while maintaining 20mTorr, an anisotropic etch profile with the SiO2 etch rate of 3350 ?min and the etch selectivity of higher than 6 over ACL could be obtained.

Keywords: dielectric material etching, Dual-frequency CCP, VHF source

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