The reaction of the NO molecule at the 4H-SiC/SiO₂ interface after dry oxidation is theoretically investigated on the basis of ab initio calculations. On the Si-face, the reaction of the NO molecule results in the dissociation of the C–C single bond and the formation of Si₄–N bonds with the CO₂ molecule. In contrast, the C=C double bond changes into the C–C bond with the formation of Si₃–N bonds and CO₂ desorption on the C-face. This C–C bond on the C-face can be removed by the incorporation of an additional NO molecule. For the resultant interface structures, no localized electronic states are generated around the energy gap of 4H-SiC, suggesting that the NO annealing process is crucial to reduce the carbon-related defects at the 4H-SiC/SiO₂ interface. Furthermore, the reaction on the NO molecule at the interface with CO desorption after dry oxidation is discussed in order to clarify the behavior of the NO molecule during the annealing process at 4H-SiC/SiO₂ interfaces.

理论上根据从头算的方法研究了干法氧化后4H-SiC / SiO ₂界面上NO分子的反应。在Si面上，NO分子的反应导致CC单键解离，并与CO ₂分子形成Si ₄ -N键。相反，随着Si ₃ -N键和CO ₂的形成，C = C双键变为CC键在C面上解吸。可以通过引入其他NO分子来去除C面上的C C键。对于所得的界面结构，在4H-SiC的能隙附近没有产生局部电子态，这表明NO退火工艺对于减少4H-SiC / SiO ₂界面的碳相关缺陷至关重要。此外，为了阐明在4H-SiC / SiO ₂界面退火过程中NO分子的行为，讨论了干氧化后NO分子在界面上的反应以及CO解吸。