Impact of random telegraph noise on CMOS logic delay uncertainty under low voltage operation

Statistical nature of RTN-induced delay fluctuation is described by measuring 2,520 ROs fabricated in a commercial 40 nm CMOS technology. Small number of samples have a large RTN-induced delay fluctuation. RTN-induced delay fluctuation becomes as much as 10.4% of nominal oscillation frequency under low supply voltage (0.65V). By slightly increasing the transistor size, more than 50% reduction of frequency uncertainty can be achieved under 0.75V operation. The impact of the parameters that can be changed by circuit designers is clarified in view of RTN-induced CMOS logic delay uncertainty.