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

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: (100) and (110). 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 (100) channel orientation deliver a larger drive current by about 11% more than their counterparts with a (110) 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.