Influence of sidewall thickness variation on transfer characteristics of L-shaped Impact-ionization MOS transistor

In this study, the influence of sidewall thickness on the threshold voltage and on-current of L-shaped Impact-ionization metal-oxide-semiconductor transistor (I-MOS) is investigated. For the sidewall thickness in the range of 10 nm to 20 nm, the devices of thicker sidewall show lower on-current and higher threshold voltage. This is because the electron concentration between the channel and the most active ionization region rapidly decreases as the sidewall gets thicker. As a result, a precise control of sidewall formation is needed in fabricating L-shaped I-MOS devices. Also, obtaining the required on-current and reliability at the same time, as well as suppressing device variability due to sidewall thickness variation, is expected to be challenging.