Power field-effect transistor having a trench gate electrode and method of making the same

摘要

A technique is provided which makes it possible to reduce the area of a power MOSFET (1) of the trench type in which a source region (27) is exposed on both of a substrate top surface (51) and a sidewall (52) of a trench (18). Since this makes it possible to provide contact between the source region (27) and a source electrode (29) not only on the substrate top surface (51) but also on the sidewall (52) of the trench (18), source contact is provided with a sufficiently low resistance and the area of the device can be made smaller.