A semiconductor standard cell of a flip-flop circuit includes semiconductor fins extending substantially parallel to each other along a first direction, electrically conductive wirings disposed on a first level and extending substantially parallel to each other along the first direction, and gate electrode layers extending substantially parallel to a second direction substantially perpendicular to the first direction and formed on a second level different from the first level. The flip-flop circuit includes transistors made of the semiconductor fins and the gate electrode layers, receives a data input signal, stores the data input signal, and outputs a data output signal indicative of the stored data in response to a clock signal, the clock signal is the only clock signal received by the semiconductor standard cell, and the data input signal, the clock signal, and the data output signal are transmitted among the transistors through at least the electrically conductive wirings.