Experimental study of variability in polycrystalline and crystalline silicon channel FinFET CMOS inverters

Polycrystalline-silicon (poly-Si) and crystalline-silicon (crystal-Si) channel FinFET CMOS inverters were successfully fabricated and the variations of threshold voltage (V
_t
) for their individual n- and p-channel transistors and the logic gate V
_t
(V
_Thc
) for the inverters were systematically investigated. It was found that poly-Si n- and p-channel devices show about 3 and 5 times larger σV
_t
values, respectively and about 2 times larger σV
_Thc
as compared to those in crystal-Si channel ones. The calculated σV
_THC
values by using the error propagation low are good agreement with experimental results.