Basal Plane Dislocation Mitigation Using High Temperature Annealing in 4H-SiC Epitaxy

Basal plane dislocations (BPD) were mostly eliminated in 4H-SiC epitaxy using post growth high temperature annealing in the range of 1600 oC - 1950 oC for 30s - 2 mins. The samples annealed at temperatures >1700 oC showed the best BPD reduction. However, surface morphology was degraded for samples annealed >1850 oC, and new BPDs were generated. A better capping technique was developed to improve the surface morphology and avoid generation of new BPDs, while significantly reducing the existing BPDs in the SiC epitaxial layers.