Investigation of electrically active defects of silicon carbide using atomistic scale modeling and simulation

In this paper, we have identified the electrically active point defects of silicon carbide, characterized their defect energetics which provide a qualitative understanding about defect formation probability, and suggested passivation techniques for the highly probable electrically active defects. The perturbation of electronic properties due to typical defects and the probabilities of generation of the defects have been explored using atomistic scale modeling and simulations. It is observed that the native (or intrinsic) point defects of SiC are electrically active and have energy levels within the band gap of 4H-SiC. While it is possible to passivate Si vacancies using atomic hydrogen, C vacancies cannot be passivated in a similar way. Our computational observation and explanation of significant reduction in trap density by diffusing in atomic hydrogen can elucidate similar experimental observations.