Angular dependence of SiO2 etching in a fluorocarbon plasma
| Autor: | Sung-Wook Hwang, Sang Heup Moon, Gyeo-Re Lee, Byeong-Ok Cho |
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| Rok vydání: | 2000 |
| Předmět: | |
| Zdroj: | Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. 18:2791-2798 |
| ISSN: | 1520-8559 0734-2101 |
| DOI: | 10.1116/1.1318193 |
| Popis: | SiO2 etch rates in a CF4 plasma were obtained at various surface angles using a Faraday cage with pinholes on the upper plane through which ions are incident on the substrate fixed at various angles inside the cage. The reactive ion etching experiments were performed at 5 mTorr in a wide bias-voltage range from −100 to −800 V. The normalized etch-yield curves showed virtually the same angular dependence regardless of the ion incident energy. The curve shape was similar to that of physical sputtering except that the ratio of the maximum yield to that at 0° was as low as about 1.3. This is the deviation from the cosine dependence characteristic of chemical sputtering, which is the main mechanism of SiO2 etching in a fluorocarbon plasma. This deviation is partly attributed to the fluorocarbon polymer film, which existed as a few monolayers-thick film on the substrate surface at low angles near 0° but as a submonolayer at high angles between 45° and 75°. The effect of the film-coverage difference on the devia... |
| Databáze: | OpenAIRE |
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