On Relationships between Plasma Chemistry and Surface Reaction Kinetics Providing the Etching of Silicon in CF<sub>4</sub>, CHF<sub>3</sub>, and C<sub>4</sub>F<sub>8</sub> Gases Mixed with Oxygen
Seung Yong Baek,
Alexander Efremov,
Alexander Bobylev,
Gilyoung Choi,
Kwang-Ho Kwon
Affiliations
Seung Yong Baek
Department of Computer Science and Technology, Korea University, Sejong 30019, Republic of Korea
Alexander Efremov
Department of Electronic Devices & Materials Technology, State University of Chemistry & Technology, 7 Sheremetevsky av., Ivanovo 153000, Russia
Alexander Bobylev
Department of Electronic Devices & Materials Technology, State University of Chemistry & Technology, 7 Sheremetevsky av., Ivanovo 153000, Russia
Gilyoung Choi
Department of Control and Instrumentation Engineering, Korea University, Sejong 30019, Republic of Korea
Kwang-Ho Kwon
Department of Control and Instrumentation Engineering, Korea University, Sejong 30019, Republic of Korea
In this work, we discuss the effects of component ratios on plasma characteristics, chemistry of active species, and silicon etching kinetics in CF4 + O2, CHF3 + O2, and C4F8 + O2 gas mixtures. It was shown that the addition of O2 changes electrons- and ions-related plasma parameters rapidly suppresses densities of CFx radicals and influences F atoms kinetics through their formation rate and/or loss frequency. The dominant Si etching mechanism in all three cases is the chemical interaction with F atoms featured by the nonconstant reaction probability. The latter reflects both the remaining amount of fluorocarbon polymer and oxidation of silicon surface.
