Abstract: A semiconductor device includes a plurality of semiconductor regions of a first conductive type and a plurality of semiconductor regions of a second conductive type. AMOS transistor having a channel of the second conductive type is formed in the semiconductor regions of the first conductive type, and a bipolar transistor and a MOS transistor having a channel of the first conductive type are formed in the semiconductor regions of the second conductive type.

Abstract: A novel gate circuit is disclosed. A first semiconductor switch includes a couple of main terminals connected between a first potential level and an output node, in which a high impedance state is held in response to an input signal having a first logic level and a second logic level, and the impedance state changes from high to low only during a transient period when the input signal changes substantially from the first to second logic level. A second semiconductor switch includes a couple of main terminals inserted between a second potential level different from the first potential level and the output node, in which a high impedance state is held in response to the input signal, and the impedance state changes from high to low only during a transient period when the input signal changes from the second to first logic level.

Abstract: A semicondcutor device and a manufacturing method thereof are disclosed in which higher integration can be achieved without increasing the total manufacturing steps. The semiconductor device includes at least two MOS transistors having the same channel types, the gate electrodes of which are constructed of polycrystal silicon layers which contain an impurity, and a bipolar transistor, the base electrode of which is constructed of a polycrystal silicon layer which contains and impurity. In particular, the respective gate electrodes of the two MOS transistors contain impurities of different conductivity types from one another.