US Patent 7605601 Semiconductor integrated circuit device

A semiconductor integrated circuit device, has a semiconductor substrate; and a first transistor of a first conductivity type and a second transistor of the first conductivity type, the transistors being connected in series between a first power supply line and a first substrate well provided on the semiconductor substrate, the semiconductor integrated circuit device further comprising a first transistor of a second conductivity type and a second transistor of the second conductivity type, the transistors being connected in series between the second power supply line and a second substrate well provided on the semiconductor substrate.