Implementation of the Density Gradient Quantum Corrections for 3-D Simulations of Multigate Nanoscaled Transistors

IEEE Trans. Electron Devices

et al. 2016

Self Cite

Copies of full items can be used for personal research or study, educational, or not-for profit purposes without prior permission or charge. Provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way.Publisher's statement: "© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works." A note on versions:The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP url' above for details on accessing the published version and note that access may require a subscription. Abstract-The fin edge roughness (FER) and the TiN metal grain work-function (MGW) induced variability affecting off and on device characteristics is studied and compared between a 10.4 nm gate length In 0.53 Ga 0.47 As FinFET and a 10.7 nm gate length Si FinFET. We have analysed the impact of variability by assessing five figures of merit (V T , SS, I OFF , DIBL and I ON ) using two state-of-the-art in-house-build 3-D simulation tools based on the finite element method. Quantum-corrected 3-D drift-diffusion simulations are employed for variability studies in the sub-threshold region while, in the on-region, we use quantum-corrected 3-D ensemble Monte Carlo simulations. The In 0.53 Ga 0.47 As FinFET is more resilient to the FER and MGW variability in the sub-threshold compared to the Si FinFET due to a stronger quantum carrier confinement present in the In 0.53 Ga 0.47 As channel. However, the on-current variability is between 1.1-2.2 times larger for the In 0.53 Ga 0.47 As FinFET than for the Si counterpart, respectively.

Section: Finfet Modellingmentioning

confidence: 99%

Comparison of Fin-Edge Roughness and Metal Grain Work Function Variability in InGaAs and Si FinFETs

Seoane

Indalecio

IEEE Trans. Electron Devices

et al. 2016

Self Cite

“…In this paper, we have presented a 3D density-gradient quantum-corrected Drift-Diffusion [5] and Monte Carlo [10] simulation study of the TiN metal gate workfunction variability on the off-and on-currents for a 10.4 nm gate length In 0.53 Ga 0 .47As FinFET [1]. Three grain sizes have been considered in this study: 10, 7 and 5 nm which are observed experimentally in TiN metal gates [13].…”

Section: Discussionmentioning

confidence: 99%

“…Both simulators include Fermi-Dirac statistics due to the heavily doped source/drain regions [4]. Quantum corrections are calibrated via the effective masses in x, y and z-directions that characterise the DG approach, which can mimic the source-to-drain tunnelling and quantum confinement effects [5]. MC simulation results show a greater on-current variability, over a 120% increase, compared with DD simulations.…”

Section: Discussionmentioning

confidence: 99%

“…The 3D ensemble MC [3] and DD [1] simulators are both based on the finite-element method (FEM), consider FermiDirac statistics (due to the high level of degeneracy of the S/D regions [4]), and include quantum corrections through an optimised FEM density gradient (DG) approach for multigate transistors [5]. Quantum corrections are calibrated via the effective masses that characterise the DG solution, which are related to the source-to-drain tunnelling and quantum confinement effects [1].…”

Section: Simulation Methodologymentioning

confidence: 99%

See 1 more Smart Citation

MC/DD study of metal grain induced current variability in a nanoscale InGaAs FinFET

Seoane

2014 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD)

Kálna

et al. 2014

The on-and off-current variability due to TiN metal grain workfunction fluctuations in a 10.4 nm gate length In0.53Ga0.47As FinFET is analysed using two in-house simulation tools based on the finite element method: a 3D Drift-Diffusion device simulator and a 3D ensemble Monte Carlo simulator, that include quantum-corrections through the density gradient approach. The ID-VG characteristics have been compared in the subthreshold region against ballistic NEGF simulations, showing an excellent agreement.Monte Carlo simulations, considering a 100 channel orientation, show a larger on-current variability, over a 120% increase, compared with the results from Drift-Diffusion simulations. In this study, three different metal grain sizes (10, 7 and 5 nm) have been analysed. We have observed that the underestimation of the variability when using Drift-Diffusion simulations is increasing with a reduction in the grain size.

“…The value for ∆ RM S was taken from experimental data in Si FinFETs [17] and verified in the simulation of a 25 nm gate length FinFET [5], whereas the correlation length Λ is assumed to be as in planar MOSFETs [18], [19]. Quantum corrections are included through the density gradient approach [20] and they are assumed to be fixed during the MC simulation [21].…”

Section: A Monte Carlo Simulationsmentioning

confidence: 99%

Self-forces in 3D finite element Monte Carlo simulations of a 10.7 nm gate length SOI FinFET

2014 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD)

Kálna

2014

Particle-mesh coupling in ensemble Monte Carlo simulations of semiconductor devices results in unphysical selfforces when using unstructured meshes to describe the device geometry. We develop a correction to the driving electric field and show that self-forces can be virtually eliminated on a finite element mesh at a small additional computational cost. The developed methodology is included into a self-consistent 3D finite element Monte Carlo device simulator. We simulate an isolated particle and show the kinetic energy conservation down to a magnitude of 10 −10 meV. The methodology is applied to a 10.7 nm gate length FinFET simulation and we find that for a large enough ensemble of particles, the impact of self-forces on the final ID-VG is almost negligible.