Deep Level investigation of pn-junctions formed by MeV aluminum and boron implantation into 4H-SiC

ICTS measurements on aluminum, aluminum/carbon, boron? and boron/carbon implanted pn-diodes annealed at 1600 degreesC and 1800 degreesC for 30 min were performed to investigate doping related and implantation induced traps in the vicinity of the pn-junction. An Arrhenius plot analysis was used to determine the trap ionization energies. From this analysis the identified traps can be divided into two groups; one group can be related to the shallow dopants nitrogen and aluminum. The second group consists of deep centers, which can be identified as the implantation induced Z(1)- center and the boron related B-center, The concentration of the Z(1)-center was reduced by at least 1- 2 orders of magnitude in pn-diodes annealed at 1800 degreesC compared with pn-diodes annealed at 1600 degreesC.