Surface analysis and defect characterization of 4H-SiC wafers for power electronic device applications

4H-SiC wafers and epitaxial layers were analysed by optical microscopy, profilometer technique and scanning electron microscopy with the aim to evidence the defect morphology on large scale and to determine in both cases the different types of defects. A more detailed analysis has been performed by atomic force microscopy. Different types of defects such as micropipes, comets, super dislocations, etch pits and so on, have been characterized finding particular physical finger-prints. Electrical characterization performed on Schottky diodes realized on 4H-SiC wafers gave information about the correlation between defects and electrical performances of devices. (C) 2002 Elsevier Science B.V. All rights reserved.