1 March 1991 In-situ measurements of radicals and particles in a selective silicon oxide etching plasma
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Proceedings Volume 1392, Advanced Techniques for Integrated Circuit Processing; (1991); doi: 10.1117/12.48940
Event: Processing Integration, 1990, Santa Clara, CA, United States
Selective silicon oxide etching plasmas typically use fluorocarbon feedgases under polymerizing conditions to provide etch selectivity and anisotropy. This work reports in—situ measurements of radical and particle distributions in the CF4-CHF3 plasma, one of the commonly used feedgas mixtures for selective oxide etching relative to silicon. Laser-induced—fluorescence (LIF) is used to monitor trends in the concentration of CF radicals in the ground electronic and vibrational state. Mie scattering observed in the perpendicular direction gives information about particles in the plasma. The effects of addition of Ar diluent on radical concentrations and etch rates are also reported. The dependence of plasma particle contamination on the proportion of CHF3 in the feedgas mix and its correlation with gas phase radical concentration is measured. It is also shown that an interrupted plasma discharge results in a significant reduction in the gas phase particle formation as compared to a continuous discharge.
© (1991) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jyothi Singh, "In-situ measurements of radicals and particles in a selective silicon oxide etching plasma", Proc. SPIE 1392, Advanced Techniques for Integrated Circuit Processing, (1 March 1991); doi: 10.1117/12.48940; https://doi.org/10.1117/12.48940





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