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
In this work, we discuss the effects of component ratios on plasma characteristics, chemistry of active species, and silicon etching kinetics in CF<sub>4</sub> + O<sub>2</sub>, CHF<sub>3</sub> + O<sub>2</sub>, and C<sub>4</sub>F<sub>8...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-07-01
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| Series: | Materials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1996-1944/16/14/5043 |
| Summary: | In this work, we discuss the effects of component ratios on plasma characteristics, chemistry of active species, and silicon etching kinetics in CF<sub>4</sub> + O<sub>2</sub>, CHF<sub>3</sub> + O<sub>2</sub>, and C<sub>4</sub>F<sub>8</sub> + O<sub>2</sub> gas mixtures. It was shown that the addition of O<sub>2</sub> changes electrons- and ions-related plasma parameters rapidly suppresses densities of CF<sub>x</sub> 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. |
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| ISSN: | 1996-1944 |