Aspects of the invention include systems and methods for implementing a CMOS circuit design that uses a sea-of-gates fill methodology to provide latch-up avoidance. A non-limiting example computer-implemented method includes identifying a fill cell in the circuit design. The fill cell can include a power rail, a ground rail, and a field-effect transistor (FET) electrically coupled to the power rail through a via. The method can include disconnecting the via from the power rail and moving the via to a disconnected node in the fill cell. Moving the via decouples a source or drain of the fill cell from a well of the fill cell, preventing latch-up while maintaining via and metal shape density.