Jihyun Seo

Nanoscale Device Modeling and Simulation: Fin Field-Effect Transistor (FinFET)

The device performance of nanoscale fin field-effect transistor (FinFET) was investigated by numerically solving coupled Poisson-Schrodinger equations in a self-consistent manner. The number of fins was varied in order to optimize the current driving capability of FinFET. The simulation results were compared with the experimental results in order to verify the validity of the proposed quantum mechanical approach. Device optimization was theoretically performed in order to suppress the short-channel effect in terms of subthreshold swing, threshold voltage roll-off, and drain-induced barrier lowering. Quantum mechanical simulation results were also compared with the results from the classical approach in order to understand the influence of electron confinement. Our simulation results indicate that quantum mechanical simulation is essential for the realistic optimization of the FinFET structure.

Molecular Dynamics Calculation for Low-Energy Ion Implantation Process with Dynamic Annealing Effect

In this paper, we present a molecular dynamics (MD) study on a low-energy ion implantation process for nanoscale CMOS (Complementary Metal Oxide Semiconductor) processes. To model the profiles of interstitials and vacancies, the recoil interaction approximation (RIA) was employed, while the kinetic Monte Carlo (KMC) approach was used for modeling the dynamic annealing effect between cascades. The simulation results performed for as-implanted boron profiles were compared with the results of the binary collision approximation (BCA) calculation by UT-MARLOWE as well as with the experimental SIMS data. The simulation revealed that the dynamic annealing effect between cascades is essential for the accurate estimation of defect distribution as well as as-implanted ion distribution. The dynamic annealing effect was carefully investigated for a case of boron implantation with an ion implantation energy of 2 keV, doses of 1×1014 ions/cm2 and 1×1015 ions/cm2, and a dose rate of 1×1012 ions/cm2s.

Molecular Dynamics (MD) Calculation for Low-energy Ion Implantation Process with Dynamic Annealing Effect

In this paper, we report a molecular dynamics (MD) simulation on the ion implantation for nano-scale CMOS devices with ultra-shallow junctions. In order to model the profile of ion distribution in nanometer scale, the molecular dynamics with a damage model has been employed with the Kinetic Monte Carlo (KMC) diffusion model used for the dynamic annealing between cascades. The concentration distribution of dopants during the ion implantation was calculated using the interaction potentials between atoms [1,2] from MD calculation.

Process and device simulation based on atomistic and quantum mechanical approach in the regime of sub-50 nm gate length

In this paper, we report simulation methods based on atomistic approach for sub-50 nm gate length. Molecular dynamics (MD) is implemented for the ion implantation process to form ultra-shallow junctions. And then, the diffusion process is simulated by using kinetic Monte Carlo (KMC) with the damages and dopants distribution from ion implantation in MD. A device simulation is performed by using profiles from the results of KMC. As an exemplary case, we demonstrate FinFET of 20nm physical gate length.

Nano-scale device modeling and simulation: FinFET

In this paper, two-dimensional quantum mechanical simulation of FinFET is reported. Current-voltage characteristics are compared with the experimental data. Device optimization has been performed in order to suppress the short-channel effect inculating the subthreshhold swing, threshold voltage rool-off, drain induced barrier lowering (DIBL). The QM simulation is compared with the classical approach in the order to understand the influenece of the electron confinement effect.