Enhanced oxidation of sic substrates using La2O3 capped annealing and a proposal for uniform LaSiON gate dielectric formation

In this paper, Enhanced oxidation of SiC(0001) substrates using La₂O₃ capped annealing has been presented. Compared to thermal oxidation, lower oxidation temperature can be implemented to form SiO₂ layer, owing to higher oxidation rate by 10 times with La₂O₃ capped oxidation by catalytic effect of the film. Although oxidation kinetics are based on oxidation through step faces, the roughness of created SiO₂ has shown improved surface and interface over conventional dry oxidation, owing to oxygen radical oxidation induced by La₂O₃. Here, we propose a novel LaSiON dielectric formation based on the reaction of SiN and La₂O₃ layers. Owing to amorphous nature of the initial SiN_x film, a uniform LaSiON film both thickness and composition parallel to the surface can be achieved. As oxidation of SiC substrates is inhibited, face dependent oxidation to cause thickness distribution can be eliminated.