Patent ID: 7504703

Claim:
A semiconductor integrated circuit device, comprising: a semiconductor substrate having a first surface; first wells of first conductive type formed on the semiconductor substrate; second wells of second conductive type formed on the semiconductor substrate, the first wells surrounding each of the second wells on the first surface, the second wells surrounding each of the first wells on the first surface, one of the first wells and one of the second wells which are adjacent to each other composing a well pair; and an inverter pair composed of a first inverter and a second inverter, an input and an output of the first inverter being electrically connected to an output and an input of the second inverter respectively, transistors composing the inverter pair being formed in the well pair, wherein the first wells and the second wells are quadrate on the first surface, all sides of each of the first wells are shared by sides of the second wells, and all sides of each of the second wells are shared by the sides of the first wells.