Elimination of Basal Plane Dislocations in Epitaxial 4H-SiC via Multicycle Rapid Thermal Annealing

Elimination of basal plane dislocations (BPDs) in epitaxial 4H-SiC is demonstrated via a novel pulsed annealing technique in a moderate N2 overpressure of 0.55 MPa. BPD removal in 15 µm thick epitaxial 4H-SiC was confirmed using ultraviolet photoluminescence (UVPL) imaging before and after the annealing process. The samples were capped with a carbon cap, introduced into the annealing chamber, and brought up to a base temperature (TBASE) of around 1550 °C for the pulsed anneal. The multicycle rapid thermal anneal (MRTA) was then performed in the TBASE:TMAX range, where TMAX = 1875 °C was the peak temperature reached by the annealing cycles. Post-anneal surface quality and carrier lifetime were characterized by atomic force microscopy and time-resolved photoluminescence decay.