Smoothing single-crystalline SiC surfaces by reactive ion etching using pure NF{sub 3} and NF{sub 3}/Ar mixture gas plasmas
- Department of Molecular Chemistry and Biochemistry, Faculty of Science and Engineering, Doshisha University, 1-3 Miyako-dani, Tatara, Kyotanabe, Kyoto 610-0321, Japan and Department of Applied Chemistry, Graduate School of Engineering, Doshisha University, 1-3 Miyako-dani, Tatara, Kyotanabe, Kyoto 610-0321 (Japan)
- Department of Applied Chemistry, Graduate School of Engineering, Doshisha University, 1-3 Miyako-dani, Tatara, Kyotanabe, Kyoto 610-0321 (Japan)
- Department of Molecular Chemistry and Biochemistry, Faculty of Science and Engineering, Doshisha University, 1-3 Miyako-dani, Tatara, Kyotanabe, Kyoto 610-0321 (Japan)
- Toyo Tanso Co, Ltd., 5-7-2 Takeshima, Nishi yodogawa-ku, Osaka 555-0011 (Japan)
- Department of Molecular Chemistry and Biochemistry, Faculty of Science and Engineering, Doshisha University, 1-3 Miyako-dani, Tatara, Kyotanabe, Kyoto 610-0321, Japan and Department of Applied Chemistry, Graduate School of Science and Engineering, Doshisha University, 1-3 Miyako-dani, Tatara, Kyotanabe, Kyoto 610-0321 (Japan)
In pure NF{sub 3} plasma, the etching rates of four kinds of single-crystalline SiC wafer etched at NF{sub 3} pressure of 2 Pa were the highest and it decreased with an increase in NF{sub 3} pressure. On the other hand, they increased with an increase in radio frequency (RF) power and were the highest at RF power of 200 W. A smooth surface was obtained on the single-crystalline 4H-SiC after reactive ion etching at NF{sub 3}/Ar gas pressure of 2 Pa and addition of Ar to NF{sub 3} plasma increased the smoothness of SiC surface. Scanning electron microscopy observation revealed that the number of pillars decreased with an increase in the Ar-concentration in the NF{sub 3}/Ar mixture gas. The roughness factor (R{sub a}) values were decreased from 51.5 nm to 25.5 nm for the As-cut SiC, from 0.25 nm to 0.20 nm for the Epi-SiC, from 5.0 nm to 0.7 nm for the Si-face mirror-polished SiC, and from 0.20 nm to 0.16 nm for the C-face mirror-polished SiC by adding 60% Ar to the NF{sub 3} gas. Both the R{sub a} values of the Epi- and the C-face mirror-polished wafer surfaces etched using the NF{sub 3}/Ar (40:60) plasma were similar to that treated with mirror polishing, so-called the Catalyst-Referred Etching (CARE) method, with which the lowest roughness of surface was obtained among the chemical mirror polishing methods. Etching duration for smoothing the single-crystalline SiC surface using its treatment was one third of that with the CARE method.
- OSTI ID:
- 22317968
- Journal Information:
- Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films, Vol. 32, Issue 5; Other Information: (c) 2014 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0734-2101
- Country of Publication:
- United States
- Language:
- English
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