Coupled Mechanical and 3-D Monte Carlo Simulation of Silicon Nanowire MOSFETs

Abstract

In this paper we report on a general methodology to investigate nanowire MOSFETs based on the coupling of mechanical simulation with 3-D real-space Monte Carlo simulation. The Monte Carlo transport model accounts for both strain silicon and quantum mechanical effects. Mechanical strain effects are accounted for through an appropriate change of the anisotropic band structure computed with the empirical pseudopotential method. Quantum effects are instead included by means of a quantum mechanical correction of the potential coming from the self-consistent solution of the Schrödinger equation. This methodology has been then applied to the simulation of a test case silicon nanowire n-MOSFET. Impact of mechanical strain and quantum effects on the drive current is investigated. It is shown that only the inclusion of strain and quantum mechanical effects allows a good agreement with experimental data, demonstrating the validity of the proposed methodology for ultimate devices.Index Terms-Monte Carlo simulation, nanowire MOSFET, quantum effects, strained silicon.

Strain Effects in p-type Devices using Full-Band Monte Carlo Simulations

“…Several works on silicon nanowires have shown that these effects may influence substantially their electrical and mechanical properties. In particular, for diameter smaller than 20 nm, many physical quantities such as the Young's modulus, the Poisson ratio, the electron and hole effective mass, the band gap and the mobility are strongly affected with respect to bulk data (Leu et al, 2006;Leu et al, 2008;Ghetti et al, 2007). However, in this study, to compare with available experimental data, we simulated structures with minimum thicknesses of 80 nm which is much larger than the critical size mentioned above.…”

Cylindrical Silicon Nanowire Transistor Modeling Based on Adaptive Neuro-Fuzzy Inference System (ANFIS)

“…Number of attempts have been accomplished for modeling and simulation of SNWTs with numerical methods that are based on different models like selfconsistent numerical model, Monte Carlo transport model, non equilibrium Green function (NEGF) approach and etc [6][7][8][9][10]. These methods are complicated and take a lot of simulation times.…”

Reduction of the self-forces in Monte Carlo simulations of semiconductor devices on unstructured meshes

“…However, the solution time and memory requirements can be significantly reduced using an optimised device mesh. Second, some of the novel thin-body transistor architectures, which are expected to replace the conventional bulk transistors during the process of scaling into nanometre dimensions, do not have planar geometry [6]. For example, the TriGate FinFET architecture, shown in Fig.…”

“…MC device simulators built using tetrahedral elements have been presented in the past [6,10] but, to our best knowledge, the problem of the self-forces has not been treated. This is an effect which appears in self-consistent simulations and leads to artificial forces and will be discussed in Section 3.…”