Drain current saturation at high drain voltage due to pinch off instead of velocity saturation in sub-100 nm metal–oxide–semiconductor transistors

Older MOS transistor theory pointed out that drain current saturation is due to pinch off for MOS transistors with large gate length and due to velocity saturation for MOS transistors with sub-micron gate length. Newer quasi-ballistic transport theory pointed out that there is no velocity saturation. In this letter, we report our experimental observation that for sub-100 nm MOS transistors, there is no strong velocity saturation in the traditional sense and current saturation is mainly due to pinch off.