Impact of Effective Mass on Transport Properties and Direct Source-to-Drain Tunneling in Ultrascaled Double Gate Devices: a 2D Multi-Subband Ensemble Monte Carlo study

In the simulation-based research of aggressively scaled CMOS transistors, it is mandatory to combine advanced transport simulators and quantum confinement effects with first-principle techniques, which are the state-of-the-art to calculate the electronic band structure of nanomaterials. In this work, we have calculated the effective masses in DGSOI transistors and FinFETs using density functional theory (DFT) and investigate their impact on direct Source-to-Drain tunneling (S/D tunneling) using a 2D Multi-Sub-band Ensemble Monte Carlo (MS-EMC) simulator. The results for a particular V DS = 0.5 V show that, in the subthreshold regime, the effective mass variation increases the tunneling probability for the DGSOI transistor leading to a current degradation, whereas this difference is reduced and even reversed for the FinFET.