Characteristics and analysis of 4H-SiC PiN diodes with a carbon-implanted drift layer

The characteristics of 4H-SiC PiN diodes with a carbon-implanted drift layer was investigated and the reason of characteristics improvement was analyzed. The forward voltage drops of the diodes with carbonimplanted drift layer were around 3.3 V, which is lower than that of devices without carbon implantation, the specific-on resistance was decreased from 9.35 to 4.38 mΩcm2 at 100 A/cm2, and the reverse leakage current was also decreased. The influence of carbon incorporation in the Si C crystalline grids was studied by using deep-level transient spectroscopy（DLTS）. The DLTS spectra revealed that the Z1/2 traps, which were regarded as the main lifetime limiting defects, were dramatically reduced. It is proposed that the reduction of Z1/2 traps can achieve longer carrier lifetime in the drift layer, which is beneficial to the performance of bipolar devices.