| 摘要 |
PURPOSE:To heighten breakdown endurance by deeply forming a second base region, which does not form a conductive type MOSFET similar to a first base region forming a vertical MOSFET as compared with the first base region. CONSTITUTION:A unit cell part 15 forming a MOSFET having an n-type epitaxial Si layer 2 formed on a high concentration n-type Si substrate 1 as a semiconductor substrate consists of the same p-type region for forming a p-type base layer 4 and a channel part and an n<+> type source region 5 formed therein, while a gate oxide film 7 and a gate electrode 8 extend between unit cells and a source electrode 10 is on a gate electrode 8 through an insulating layer 9. On the other hand, in a diode part 14 a p-type base region 3 equal to a base region of a unit cell is formed deeper than a p-type base region 4 of a unit cell part 15 while being connected to the source electrode 10. Thereby, when reverse voltage is impressed between a drain and a source, breakdown occurs in the other base region than the base region, in which the MOSFET is formed, so that concentration of a breakdown current due to dispersion of forming the base regions can be prevented. |
