MOS FIELD EFFECT SEMICONDUCTOR DEVICE WITH HIGH BREAKDOWN VOLTAGE

摘要

PURPOSE:To improve the reliability of an MOSFET with high breakdown voltage by a method wherein the substrate surface of an MOSFET with high breakdown voltage is covered with a low-resistance layer having a fixed potential through an insulating layer so that said MOSFET is independently of the external charge. CONSTITUTION:In a semiconductor substrate 1 in which impurity has been diffused, a conductor or low-resistance layer 13 is formed so as to cover the region of a pinch resistance layer 5 through an insulating film 11. The conductor or low-resistance layer 13 is electrically connected to a source-side field plate 8' and a drain- side electrode 9 through high-resistance bodies 15 and 16 respectively in order to fix the potential of the conductor or low-resistance layer 13 in operation at an intermediate potential between the source and drain.