3-D Finite Element Monte Carlo Simulations of Scaled Si SOI FinFET With Different Cross Sections

Abstract

Nanoscaled Si SOI FinFETs with gate lengths of $12.8$ and $10.7$ nm are simulated using 3-D finite element Monte Carlo (MC) simulations with 2-D Schrodinger-based quantum corrections. These nonplanar transistors are studied for two cross sections: rectangular-like and triangular-like, and for two channel orientations: $\langle 100\rangle$ and $\langle 110\rangle$ . The $10.7$ -nm gate length rectangular-like FinFET is also simulated using the 3-D nonequilibrium Green’s functions (NEGF) technique and the results are compared with MC simulations. The $12.8$ and $10.7$ nm gate length rectangular-like FinFETs give larger drive currents per perimeter by about 33–37% than the triangular-like shaped but are outperformed by the triangular-like ones when normalised by channel area. The devices with a $\langle 100\rangle$ channel orientation deliver a larger drive current by about $11$ % more than their counterparts with a $\langle 110\rangle$ channel when scaled to $12.8$ nm and to $10.7$ nm gate lengths. $I_{D}-V_{G}$ characteristics obtained from the 3-D NEGF simulations show a remarkable agreement with the MC results at low drain bias. At a high drain bias, the NEGF overestimates the on-current from about $V_{G}-V_{T}=0.3$ V because the NEGF simulations do not include the scattering with interface roughness and ionized impurities.