Characterization of deep level defects in sublimation grown p-type 6H-SiC epilayers by deep level transient spectroscopy

In this study deep level transient spectroscopy has been performed on boron–nitrogen co-doped 6H-SiC epilayers exhibiting p-type conductivity with free carrier concentration (NA–ND)∼3×1017cm−3. We observed a hole H1 majority carrier and an electron E1 minority carrier traps in the device having activation energies Ev+0.24eV, Ec −0.41eV, respectively. The capture cross-section and trap concentration of H1 and E1 levels were found to be (5×10−19cm2, 2×1015cm−3) and (1.6×10−16cm2, 3×1015cm−3), respectively. Owing to the background involvement of aluminum in growth reactor and comparison of the obtained data with the literature, the H1 defect was identified as aluminum acceptor. A reasonable justification has been given to correlate the E1 defect to a nitrogen donor.