US Patent 7652333 Semiconductor integrated circuit

The semiconductor integrated circuit has so-called SOI type first MOS transistors (MNtk, MPtk) and second MOS transistors (MNtn, MPtn). The first MOS transistors have a gate isolation film thicker than that the second MOS transistors have. The first and second MOS transistors constitute a power-supply-interruptible circuit (6) and a power-supply-uninterrupted circuit (7). The power-supply-interruptible circuit has the first MOS transistors each constituting a power switch (10) between a source line (VDD) and a ground line (VSS), and the second MOS transistors connected in series with the power switch. A gate control signal for the first MOS transistors each constituting a power switch is made larger in amplitude than that for the second MOS transistors. This enables power-source cutoff control with a high degree of flexibility commensurate with the device isolation structure, which an SOI type semiconductor integrated circuit has originally.