SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE

PURPOSE:To improve the reliability of a protecting circuit by composing a MISFET of diode mode at its gate insulating film of the same insulating film as an interlayer insulating film, connecting its one semiconductor region and a gate electrode to wirings extended from an external electrode, and connecting the other semiconductor region to a power source potential supplying wirings. CONSTITUTION:A MlSFETQ3 of higher threshold voltage than the threshold voltage of a MISFET of an internal circuit is formed in a diode mode between an external terminal BP and a MISFET of the internal circuit. The MISFETQ3 is formed at its gate insulating film of the insulating film 5 of the same layer as the interlayer insulating film for insulating between the conductive layers, connected at one semiconductor region 4 and a gate electrode 8G to wirings 8 extended from the electrode BP, and the other semiconductor region 4 is connected to wirings 7 for supplying a power source potential Vcc to the circuit. Thus, since the threshold voltage of the MISFETQ3 can be set to the degree of the operating voltage of high level appled to the MISFET of the internal circuit, an excess charge can be rapidly discharged.