MOS field effect transistor with reduced on-resistance

摘要

A semiconductor substrate includes a first principal plane and a second principal plane opposite this first principal plane. A first semiconductor region is formed on the first principal plane of the semiconductor substrate. Second and third semiconductor regions are formed separately from each other on the first semiconductor region. A gate electrode is formed, via a gate insulator, on the first semiconductor region between the second semiconductor region and the third semiconductor region. An electric conductor is formed up to the semiconductor substrate from the second semiconductor region and electrically connects the second semiconductor region with the semiconductor substrate. A first main electrode is formed on the second principal plane of the semiconductor substrate and is electrically connected to the semiconductor substrate. A second main electrode is formed on the first semiconductor region via insulators and is electrically connected to the third semiconductor region.