Comprehensive Crystallographic Investigation of Diverse Structural Defects and Their Evolution Mechanisms in 4H-SiC for High-Reliability Power Devices

Dr. Na’s research provides a comprehensive analysis of the structure, formation, evolution, and device-level impact of crystal defects in 4H-SiC*, a material attracting significant attention for next-generation power devices. Microscopic defects in SiC wafers are a major factor affecting device performance and long-term reliability, yet the nature of these defects has been difficult to fully understand. By combining optical observation, electron microscopy, X-ray analysis, device measurements, and theoretical calculations, her work has systematically linked defect characteristics, atomic structure, formation pathways, and device impact within a single analytical framework. Her findings have shown that stacking faults* are more diverse and dynamic than previously believed and that certain defects can cause a non-linear increase in device resistance. These results provide fundamental insights for improving SiC wafer quality and realizing high-performance, highly reliable power semiconductor devices.