Multi-Cycle High Temperature Rapid Thermal Annealing for Dislocation Elimination in 4H-SiC Epitaxy

High temperature annealing of carbon capped SiC epilayers was performed using multi-cycle rapid thermal annealing technique to eliminate basal plane dislocations (BPD) and preserve the surface morphology. Annealing was performed in temperature range of 1750 o C – 1875 o C at N 2 overpressure of 0.55MPa and 0.7MPa. BPDs in the epilayers were found to be eliminated for annealing at 1875 o C for 5 mins with 20 multiple heating cycles under 0.55MPa N 2 overpressure. Under high temperature annealing, the BPDs convert to threading edge dislocations, which glides in the epilayers as the BPD retracts towards the substrate.