Semiconductor integrated circuit device

Claim 2

A semiconductor integrated circuit device,laving an element to be protected, characterised in that the device comprises a first resistive element interposed between an input terminal and the element to be protected, an insulated gate type transistor of which one of the drain and source regions is connected to the element to be protected, and theother of the drain and source regions is connected to a ground line (a line which is grounded when the device is in use), a capacitor interposed between the gate electrode of the insulated gate type transistor and the input terminal, and a second resistive element interposed between the gate of the insulated gate type transistor and a ground line.

Claim 3

A device as claimed in claim 1, wherein the element to be protected is an element of an internal circuit of the device, and the said insulated gate type transistor is fabricated in the same manner as transistors of the internal circuit.

Claim 4

A device as claimed in claim 1 or 2, wherein the insulated gate type transistor is an MIS type transistor.

Claim 5

A device as claimed in claim 1, 2 or 3, wherein the second resistive element is a resistor or a diode or a diode of reverse polarity.

Claim 8

A device as claimed in claim 3, or any of . claims 4 to 6 read as appended to claim 3, wherein the MIS transistor is a "stacked gate" type transistor comprising a silicon island, source and drain regions, a silicon gate.with a gate insulating layer of silicon dioxide and a layer of phospho-silicate glass and an aluminium electrode.

Claim 10

A device as claimed in claim 3, or 7, or any of claims 4 to 6 and 8 read as appended to claim 3, wherein the MIS transistor is an N-channel silicon gate MOS transistor.

Claim 11

A semiconductor integrated circuit device having an internal circuit and a protective circuit for protecting an element of the internal circuit, for example an input gate of an insulated gate type transistor of the internal circuit, against high voltage, for example fabricated with a silicon-on-sapphire (SOS) structure, characterised in that a transistor of the protective circuit is an insulated gate type transistor, for example fabricated in the same manner as transistors of the internal circuit, the gate of which is grounded- through a resistor or a diode of reverse polarity, with a metal electrode provided on the gate via an insulation layer, the metal electrode being arranged to receive an input signal, with one of the source and drain regions of the transistor being grounded, and the other of the source and drain regions being arranged to receive the input signal, the element to be protected being arranged to receive the input signal through a resistor.

Claim 12

A semiconductor integrated circuit device having an internal circuit and a protective circuit for protecting an element of the internal circuit, for example an input gate of an insulated gate type transistor of the internal circuit, against high voltage, for example fabricated with a silicon-on-sapphire (SOS) structure, characterised in that a transistor of the protective circuit is an insulated gate type transistor, for example fabricated in the same manner as transistors of the internal circuit, the gate of which is grounded- through a resistor or a diode of reverse polarity, with a metal electrode provided on the gate via an insulation layer, the metal electrode being arranged to receive an input signal, with one of the source and drain regions of the transistor being grounded, and the other of the source and drain regions being arranged to receive the input signal, the element to be protected being arranged to receive the input signal through a resistor.