Possible VTH Variation Sources

with 16 nm FinFET devices, the nature of the VTH variation changes.  On planar CMOS, random dopant fluctuations (RDFs) had the biggest influence. 

Possible VTH Variations

Ideal FinFETs have no doping, and therefore no RDFs.  However, this only works for low voltage operation.  We also need high-speed devices, which requires multiple threshold voltages (Vth's).  For FinFETs, this requires doping leading to RDF variation.  

[read more at DeepChip ...]