Upper/lower-side random dopant fluctuation on 16-nm-gate HKMG bulk FinFET

Abstract

In this work, we for the first time classify dopants that exist near the source/drain side or the upper/lower side of silicon fin and explore the impact of random dopants\' (RDs) position on devices\' DC characteristic. The effects of random dopant fluctuation (RDF) on the performance of 16-nm-gate HKMG bulk FinFET are studied by using experimentally validated three-dimensional RDF device simulation. The dopants near the source side or the upper fin would induce large barrier for electrons, so the threshold voltage (Vth) will be increased in n-type HKMG bulk FinFET devices which have more dopants on the source side or the upper fin. In addition, the upper-fin\'s dopants are discovered to have larger influence on the profile of energy band. Moreover, the issue about Vth\'s fluctuation on both the planar MOSFET and the bulk FinFETs with different aspect ratios (AR) is studied. The higher-AR HKMG bulk FinFET devices have relatively smaller Vth\'s variation induced by RDF.