Impact of Oxide Thickness Fluctuation for Resist- and Spacer-Defined FinFETs

Abstract

The geometrical fluctuations such as Oxide Thickness Fluctuations (OTF) and Line Edge Roughness (LER) cause intrinsic statistical variations in the nanoscale FinFET technology. The OTF is primarily caused at a semiconductor/insulator (i.e., Si/SiO2) interface by random roughness of the gate oxide layer. This research work analyzes the effect of oxide roughness on the performance parameters of resistand spacer-defined FinFETs. A large statistical ensemble has been considered to observe the effect of OTF for FinFET devices. Further, all results have been analyzed and compared with the ideal (i.e., rectangular) FinFET. These results reveal that intrinsic parameter fluctuations introduced by OTF become significant for resist-defined FinFET structures. In addition, physical insight for variability-resistant FinFET design has been realized.