Low-temperature annealing in O₂ to annihilate the fixed charges in 4H-SiC/SiO₂ interface induced by high-N-density nitridation process

A low-temperature annealing process for 4HSiC/SiO 2 stack in O 2 ambient was found to annihilate the positive fixed charges induced by the interface nitridation process effectively, while preserving the interface N density. The key to design the post-nitridation annealing process in O 2 ambient was proposed as the selection of a relatively low temperature and a sufficiently long duration, which is to selectively trigger the annihilation of fixed charges while suppressing the N-removal from the interface.