Accurate modeling of transistor stacks to effectively reduce total standby leakage in nano-scale CMOS circuits

In this work we have developed an accurate model of total leakage in a transistor stack based on the compact model of gate, subthreshold and band-to-band-tunneling leakage. Using this model, we have analyzed the opportunities for overall stand-by leakage reduction in scaled devices using transistor stacking and proved that the best input vector that minimize overall leakage depends on the relative magnitude of the different leakage components. A novel stacking technique based on the ratio of the different leakage components is proposed and its effectiveness in total leakage reduction in transistor stack and logic gate is analyzed.