Analysis of FinFET based transmission gate (TG), sense amplifier (SA), and semi dynamic (SD) Flip-flops metrics are evaluated with technology scaling from 20nm down to 7nm technology node. The impact of supply voltage variation on delay, power, and energy is reported. The power delay product of Flip-flops is enhanced with technology scaling. The optimum supply voltage value at each technology node from minimum energy perspective is evaluated which is used by the industry to optimize logic and memory circuitry designs. For instance, considering the 7nm TG Flip-flop, the optimum supply voltage from energy saving point of view occurs at 0.65V. The work also characterizes each Flip-flop according to the obtained simulation results. SD Flip-flop has the best performance, however it exhibits high power consumption. TG Flip-flop is the best choice from power dissipation perspective, but it has high clock load. SA Flip-flop has a very useful feature of monotonous transitions at the outputs, which drives fast domino logic, however it might have glitches and it is the most vulnerable to soft errors. © 2015 IEEE.