Semiconductor device having contact electrode to semiconductor substrate

摘要

An isolation region is embedded in a semiconductor substrate. The height of the upper face of the isolation region is substantially equal to the height of the surface of the semiconductor substrate. A gate electrode is formed on a gate insulating film and over the isolation region. A first side face of the gate electrode is formed over the isolation region. A second side face of the gate electrode is formed over the active region. A field insulator is formed on the isolation region. A first side face of the field insulator contacts with the first side face of the gate electrode. A second side face of the field insulator is continuous with a plane obtained by extending the side face of the isolation region. A sidewall insulator has a sidewall contacting with the second side face of the field insulator and the second side face of the gate electrode.