Base cell for implementing an engineering change order (ECO)

A circuit base cell is for implementing an engineering change order (ECO) obtained on a semiconductor substrate. The base cell may include a PMOS transistor having a first active region obtained in a first diffusion P+ layer implanted in an N-well provided for on the substrate, and an NMOS transistor having a second active region obtained in a second diffusion N+ layer implanted on the substrate in such a manner as to be electrically insulated from the first diffusion P+ layer. The cell may be characterized in that the active regions and the diffusion layers are aligned therebetween with respect to a reference axis and they are extended symmetrically in the direction orthogonal to the axis. A first and a second width may be associated with the active regions and to the diffusion layers, respectively. The first and second width may be greater than a width of the cell, which is equivalent to a pitch of the standard minimum cell.