The impact of the three-dimensional gate on the trigate FinFETs

The random dopant fluctuation is one of the most important issues for ultra-scaled CMOS devices in terms of the device architecture and manufacturing. This paper will present a unified method on the understanding of the variations caused by the random dopant and the gate oxide thickness of the trigate FinFET with a peculiar 3D gate structure. The dopant fluctuation is known to be reduced in a trigate comparing to a planar transistor, while it depends on the fin-height. Another source of variation is the gate leakage variation caused by the surface roughness effect. Both types of variation posed severe challenges for putting the trigate into the manufacturing. The method to understand these effects and the experimental procedures will be demonstrated. A measure of the variation by the Pelgrom plot will be specifically addressed.