Effect of Ar annealing temperature on SiO2/4H-SiC interface studied by spectroscopic ellipsometry and atomic force microscopy

The authors have investigated the effects of different annealing temperatures in Ar atmosphere on the SiO2/4H-SiC interfaces by spectroscopic ellipsometry (SE) and atomic force microscopy (AFM). There is a strong correlation between the annealing temperatures and the quality of SiO2/4H-SiC interface. Annealing at 600 °C can significantly improve the quality of SiO2/4H-SiC interface with no transition layer. The reasons for such improvement in the quality of the SiO2/4H-SiC interface after moderate temperature annealing at 600 °C may be explained by the formation and consumption of carbon clusters and silicon oxycarbides during annealing.