Effects of nitridation in gate oxides grown on 4H-SiC

Experiments have demonstrated that nitridation provides critically importan t improvements in the quality of SiO2-SiC interface. This article provides results and analysis aimed at developing the much needed understanding of t he mechanisms and effects associated with both annealing of pregrown oxides and direct growth in NO and N2O environments. According to the model propo sed in the article, nitridation plays a double role: (1) creation of strong Si equivalent toN bonds that passivate interface traps due to dangling and strained bonds, and (2) removal of carbon and associated complex silicon-o xycarbon bonds from the interface. This understanding of the effects of nit ridation is experimentally verified and used to design a superior process f or gate oxide growth in the industry-preferred N2O environment. (C) 2001 Am erican Institute of Physics.