Split pocket p-n-i-n tunnel field-effect transistors

In the search for a sufficiently high on-current in tunnel field-effect transistors (TFET), the p-n-i-n configuration, featuring a pocket at the source side, has led to improved on-currents and subthreshold swings (SS) compared to the typical p-i-n configuration. We demonstrate through fully quantum mechanical simulations that the SS and off-current of a normally-on p-n-i-n TFET degrade with increasing body thickness. We show that a solution is to decrease the pocket thickness, such that the device becomes normally-off. As an alternative, we present a split pocket configuration, which delivers a similar SS and on-current enhancement as a full pocket configuration, while being almost insensitive to body thickness. Thicker split pockets than full pockets are possible, while maintaining the performance enhancement compared to a p-i-n TFET.