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

Abstract

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 oC – 1875 oC at N2 overpressure of 0.55MPa and 0.7MPa. BPDs in the epilayers were found to be eliminated for annealing at 1875 oC for 5 mins with 20 multiple heating cycles under 0.55MPa N2 overpressure. Under high temperature annealing, the BPDs convert to threading edge dislocations, which glides in the epilayers as the BPD retracts towards the substrate.