Kinetics of NO nitridation in SiO2/4H–SiC

The kinetics of nitrogen incorporation in SiO2/4H–SiC using NO are presented. Samples were annealed in NO at pressures of 100 Torr and 1 atm, at temperatures from 1050 to 1175 °C, and for times from 0.5 to 6 h. Annealing in NO incorporates ∼1014 cm−2 of nitrogen at the SiO2/SiC interface. The nitrogen content initially increases with time and temperature, but nitrogen is removed at later times at temperatures above 1050 °C. This nitrogen removal, and the associated oxide growth in the SiC substrate, is caused by O2 formed by the thermal decomposition of NO. Eventually, the nitridation and oxidation reactions reach equilibrium, and the nitrogen content saturates as the oxide thickness increases.