Influence of growth rate and C/Si-ratio on the formation of point and extended defects in 4H-SiC homoepitaxial layers investigated by DLTS

4H-SiC epilayers are homoepitaxially grown on 4H-Sic substrates with different C/Si-ratios and different growth rates by the chemical vapour deposition method. DLTS investigations are applied in order to trace energetically deep states of electrically active point defects and extended defects, which may act as the Source for the degradation of electronic devices. In addition, the dependence of the DLTS signal heights on the filling pulse length is studied.