Temperature dependence of dynamic operation in ultra-thin CMOS/SIMOX

Dynamic characteristics of fully depleted ultra-thin film CMOS/SIMOX devices in the range from 50 to 300 K are presented. Discussion is focused on the propagation delay time of CMOS/SIMOX ring oscillators. Using a simple theory, it is shown that the measure propagation delay time is larger than the predicted delay time. Adopting a simple theoretical assumption, it is strongly suggested that the propagation delay time is governed ultimately by the charging and discharging time of the inversion layer in off-to-on and on-to-off processes. The results are corroborated by the fact that fully depleted CMOS/SIMOX operate with extremely small parasitic capacitances