Quantitative comparison between Z1∕2 center and carbon vacancy in 4H-SiC

In this study, to reveal the origin of the Z1∕2 center, a lifetime killer in n-type 4H-SiC, the concentrations of the Z1∕2 center and point defects are compared in the same samples, using deep level transient spectroscopy (DLTS) and electron paramagnetic resonance (EPR). The Z1∕2 concentration in the samples is varied by irradiation with 250 keV electrons with various fluences. The concentration of a single carbon vacancy (VC) measured by EPR under light illumination can well be explained with the Z1∕2 concentration derived from C-V and DLTS irrespective of the doping concentration and the electron fluence, indicating that the Z1∕2 center originates from a single VC.