SEMICONDUCTOR DEVICE HAVING SCREENING ELECTRODE AND METHOD

摘要

A semiconductor device having a screening electrode is provided to avoid an increase of gate-to-drain capacitance while preventing a breakdown voltage from being deteriorated by forming a semiconductor device in a body made of a semiconductor material and by including a screening electrode separated from a channel region. A substrate(12) has a main surface(18), including first conductivity type. A pedestal structure is formed on a part of the main surface. A conductive material is disposed along the lateral surface of the pedestal structure to confine the edge of a first conductive electrode of a semiconductor device. A first doped region of second conductivity type is formed in the main surface adjacent to the first conductive electrode. A part of the first doped region forms a channel region when the semiconductor device operates. A first current transfer region of first conductivity type is formed in the first doped region. A screening electrode adjoins the main surface, close to the first doped region and including a trench, a dielectric layer and a conductive layer. The trench is formed in the main surface. The dielectric layer is formed on the surface of the trench. The conductive layer is formed on the dielectric layer.