Impact of discrete dopants on an ultra-scaled FinFET using quantum transport simulations

In this paper we study the effect of random discrete dopants in the source/drain on the performance of a 6.6 nm channel length silicon FinFET. Due to the small dimensions of the FinFET, a quantum transport formalism based on the Non-equilibrium Greens Functions has been deployed. The transfer characteristics for several devices, which differ in location and number of dopants have been simulated. Our calculations demonstrated that discrete dopants modify the effective channel length and the height of the source/drain barrier, consequently changing the channel control of the charge. As a consequence, there is a strong effect on the variability of the off-current, sub-threshold slope and threshold voltage. Finally, we have calculated the mean and standard deviation of these parameters to quantify their variability.