Correlation between etch pits formed by molten KOH+Na2O2 etching and dislocation types in heavily doped n+-4H–SiC studied by X-ray topography

Abstract

X-ray topography (XRT) has been carried out to examine the accuracy of KOH+Na2O2 etching (KN etching) technique which was recently developed for identifying dislocation types in n+-4H–SiC (n>1019cm−3). Precise one-to-one correlation have been found between the position of etch pits and dislocations revealed by XRT. More importantly, XRT observation has also confirmed the validity of using the pit sizes formed by KN etching to distinguish threading screw dislocations from threading edge dislocations.