SEMICONDUCTOR DEVICE AND ITS MANUFACTURING METHOD

摘要

A DMOS device (or IGBT) comprises a SiC substrate (2), an n-SiC layer (3) (drift region) provided in an epitaxial layer, a gate insulation film (6) and a gate electrode (7a), a source electrode (7b) so provided as to surround the gate electrode (7a), a drain electrode (7c) provided on the lower surface of the SiC substrate (2), a p-SiC layer (4), and an n+ SiC layer 3 formed over a range from the lower part of the end of the source electrode (7b) to the lower part of the end of the gate electrode (7a). A region except the part of the surface part of the epitaxial layer where an n+ SiC layer 5 is formed has a laminate of an n-type doped layer (10a) containing a high concentration of nitrogen and an undoped layer (10b). A decrease in on-resistance and an improvement in withstand voltage on the off-time can be attained by utilizing a quantum effect.