Nitric Acid Oxidation of 3C-SiC to Fabricate MOS Diodes with a Low Leakage Current Density
書誌事項
- 公開日
- 2008
- DOI
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- 10.1149/1.2804769
- 公開者
- The Electrochemical Society
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説明
Two-step nitric acid oxidation which involves immersion in ∼ 40 wt % HNO 3 followed by immersion in 68 wt % HNO 3 at 121 °C can form a thick (e.g., 10 nm) SiO 2 layer on a 3C-SiC surface. Heat-treatment at 400°C in pure hydrogen performed after nitric acid oxidation greatly decreases the density of the leakage current flowing through the SiO 2 layer. The hydrogen treatment effectively smoothens the SiO 2 /SiC interface. When the hydrogen treatment at 400°C is performed before nitric acid oxidation, the SiC surface is greatly flattened and the subsequent nitric acid oxidation results in the SiO 2 /SiC interface having an atomic flatness. Without hydrogen treatment, SiO 2 gap states are present up to 1.5 eV from the SiO 2 valence-band maximum, and the valence-band discontinuity energy at the SiC/SiO 2 interface is 3.0 eV. With the hydrogen treatment before nitric acid oxidation, the SiO 2 gap states disappear and the valence-band discontinuity energy increases to 3.9 eV. Capacitance-voltage curves of the metal-oxide-semiconductor (MOS) diodes in which hydrogen treatment is performed before nitric acid oxidation show typical accumulation and depletion behavior.
収録刊行物
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- Journal of The Electrochemical Society
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Journal of The Electrochemical Society 155 (1), H47-, 2008
The Electrochemical Society
