| 摘要 |
PURPOSE:To make it hard for a parasitic bipolar to operate by a construction wherein a gate electrode is provided on the surface of a second layer left outside a fourth layer, with an insulating film laid in between, and a first electrode is provided on a semiconductor substrate, while a second main electrode is provided on the second and fourth layers. CONSTITUTION:A second layer 2 of a P<-> type is formed by an ion implantation method or the like through a window opened in a surface insulating film of an N-type semiconductor substrate 1, and then a third layer 3 of a P<+> type is formed by the ion implantation method or the like by using a mask which is a size smaller than the window. Next, a fourth layer 4 of an N<+> type is formed through the window by the ion implantation method or the like. A difference in the expansion in the lateral direction between the second layer 2 of a P<-> type and the fourth layer 4 of an N<+> type becomes a channel 9, and a conductive gate electrode 5 is formed on a gate insulation film 8 above the channel 9. According to this construction, it becomes hard for a parasitic bipolar to operate even on the occasion of a large current drive. |
