Abstract: A CMOS device comprising an N type semiconductor substrate, a P type well region diffused in the substrate, an n-channel MOS transistor formed in the P type well region, and a p-channel MOS transistor formed in the N type semiconductor substrate, and a method for manufacturing the CMOS device. In case the CMOS device serves as a CMOS inverter, the source region of the p-channel MOS transistor, the semiconductor substrate and the well layer constitute a parasitic PNP type bipolar transistor, and the source region of the n-channel MOS transistor, the well layer and the semiconductor substrate constitute a parasitic NPN type bipolar transistor. The product of the current amplification factor .beta..sub.1 of the PNP type bipolar transistor and the current amplification factor .beta..sub.2 of the NPN type bipolar transistor is smaller than 1.

Abstract: A semiconductor integrated circuit device comprising a CMOS circuit in which parasitic transistors form a parasitic thyristor circuit. In this device, noise absorption resistances are provided at the noise inputs to absorb noise which otherwise might become trigger pulses for the thyristors.

Abstract: A CMOS FET device which comprises an N type semiconductor substrate; a P type well layer formed in the N type semiconductor substrate; a p-channel type MOS transistor provided in the N type semiconductor substrate; an n-channel type MOS transistor formed in the P type well layer; and a noise-absorbing capacitor provided at the input or output terminal of the MOS transistor or at a power supply section.

Abstract: A CMOS device comprising an N type semiconductor substrate, a P type well region diffused in the substrate, an n-channel MOS transistor formed in the P type well region, and a p-channel MOS transistor formed in the N type semiconductor substrate, and a method for manufacturing the CMOS device. In case the CMOS device serves as a CMOS inverter, the source region of the p-channel MOS transistor, the semiconductor substrate and the well layer constitute a parasitic PNP type bipolar transistor, and the source region of the n-channel MOS transistor, the well layer and the semiconductor substrate constitute a parasitic NPN type bipolar transistor. The product of the current amplification factor .beta..sub.1 of the PNP type bipolar transistor and the current amplification factor .beta..sub.2 of the NPN type bipolar transistor is smaller than 1.

Abstract: A CMOS FET device having a P well layer diffused in an N type semiconductor substrate, a P channel MOS transistor formed on the N type semiconductor substrate, and an N channel MOS transistor provided in the P well layer, wherein the source of the P channel MOS transistor is made to have the same potential as the N type semiconductor substrate and for the source of the N channel MOS transistor is made to have the same potential as the P well layer, thereby suppressing the operation of a parasitic bipolar transistor whose base is constituted by the N type semiconductor substrate and/or a parasitic bipolar transistor whose base is formed of the P well layer.

Abstract: A CMOS device comprising an N type semiconductor substrate, a P type well layer diffused in the substrate, a p-channel MOS transistor formed in the N type semiconductor substrate an n-channel MOS transistor formed in the P type well layer. A distance from an edge of a contact hole formed in the surface of a contact region of the p-channel MOS transistor to the P well layer is so chosen to suppress an operation of a parasitic bipolar transistor whose base is formed of the substrate.