METHOD FOR MANUFACTURING SILICON CARBIDE SEMICONDUCTOR DEVICE AND SILICON CARBIDE SEMICONDUCTOR DEVICE

摘要

A silicon carbide layer having a first surface and a second surface includes a first region constituting the first surface and of a first conductivity type, a second region provided on the first region and of said second conductivity type, and a third region provided on the second region and of the first conductivity type. At the second surface is formed a gate electrode having a bottom and sidewall, passing through the third region and the second region up to the first region. An additional trench is formed, extending from the bottom of the gate trench in the thickness direction. A fourth region of the second conductivity type is formed to fill the additional trench.