Transmission electron microscope study of a threading dislocation with b = [0 0 01] + (1100) and its effect on leakage in a 4H-SiC MOSFET

摘要

Threading dislocations (TD's) in a 4H-SiC MOSFET were characterized using transmission electron microscopy with special emphasis of their effects on leakage in a p-n junction. Two types of TD's were identified; a threading near-screw dislocation (TnSD) with b = [0001] + 1/3(1120), and a threading mixed dislocation (TMD) with b = [0001] + (1100), the last of which has been found for the first time in this study. The TnSD show only negligibly small leakage, while TMD shows a large leakage. Origins of the difference in the degree of the leakage have been discussed.