Abstract: In a semiconductor device including a power MOSFET (M.sub.0) for the output stage, a temperature detection circuit produces an output signal upon detecting an abnormal rise in the chip temperature, the signal turns on a set input element (M.sub.1) in a latch circuit so that the latch circuit becomes a set state, the set output of the latch circuit turns on a control element (M.sub.5), causing the power MOSFET to become non-conductive so that it is protected from destruction. The latch circuit is not brought to a reset state even if the external gate terminal of the device is brought to zero volt. With a voltage outside the range of the normal input signal, e.g., a large negative voltage, being applied to the external gate terminal, the gate capacitance of the control element (M.sub.5) discharges, and consequently the latch circuit is brought to the reset state and the protective operation is cancelled.

Abstract: A semiconductor device has a semiconductor substrate, an insulated gate field-effect transistor section formed in the substrate and a peripheral section formed in the substrate and arranged to substantially surround the field-effect transistor section. A passivation layer of an organic material is provided over that part of the substrate in which the field-effect transistor section is not located. The device may be resin mold packaged for an enhanced humidity-resistance by making use of the fact tht the peripheral portion of the device is covered with organic resin.

Abstract: A method of fabricating semiconductor devices which include vertical elements and control elements. A well is formed by etching in a semiconductor substrate of a first conductivity type, and a first epitaxial layer having a second conductivity type opposite to the first conductivity type is epitaxially grown, followed by etching and/or grinding and/or polishing to fill said well. Further, a second epitaxial layer of the first conductivity type is epitaxially grown on the substrate and on the first epitaxial layer, and an impurity-doped layer of the second conductivity type for isolation is formed in the second epitaxial layer to penetrate therethrough. A first element is formed in the second epitaxial layer in a portion that corresponds to the well, and a second element having a vertical structure and having a current capability higher than that of the first element is formed except a portion of the second epitaxial layer that corresponds to the well.

Abstract: A semiconductor integrated circuit device is provided to include a vertical type MOSFET and a gate protection element for the MOSFET. The vertical type MOSFET is made up of a silicon layer of n-type conductivity formed on an n.sup.+ -type silicon substrate, a base region of p-type conductivity formed in the surface of the silicon layer of n-type conductivity, an n.sup.+ -type source region provided in the base region, and a gate electrode formed on a portion of the base region through a gate insulating film. The silicon substrate serves as the drain. The gate protection element is formed of a polycrystalline silicon layer which is provided on the base region through an insulating film and includes at least one pn junction. By virtue of forming the gate protection element over the base region rather than directly over the substrate, a more stable operation is achieved.