Mobility of Circular and Elliptical Si Nanowire Transistors Using a Multi-Subband 1D Formalism

We have studied the impact of the cross-sectional shape on the electron mobility of n-type silicon nanowire transistors (NWTs). We have considered circular and elliptical cross-section NWTs including the most relevant multisubband scattering processes involving phonon, surface roughness, and impurity scattering. For this purpose, we use a flexible simulation framework, coupling 3D Poisson and 2D Schrödinger solvers with the semi-classical Kubo-Greenwood formalism. Moreover, we consider cross-section dependent effective masses calculated from tight binding simulations. Our results show significant mobility improvement in the elliptic NWTs in comparison to the circular one for both [100] and [110] transport directions.

[1]  A. Asenov,et al.  Impact of quantum confinement on transport and the electrostatic driven performance of silicon nanowire transistors at the scaling limit , 2017 .

[2]  N. Mori,et al.  Three-Dimensional Quantum Transport Simulation of Ultra-Small FinFETs , 2004, 2004 Abstracts 10th International Workshop on Computational Electronics.

[3]  Xing Zhang,et al.  Experimental Investigations on Carrier Transport in Si Nanowire Transistors: Ballistic Efficiency and Apparent Mobility , 2008, IEEE Transactions on Electron Devices.

[4]  Asen Asenov,et al.  Impact of the Effective Mass on the Mobility in Si Nanowire Transistors , 2018, 2018 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD).

[5]  Carlo Jacoboni,et al.  Quantum Transport in Semiconductors , 1992 .

[6]  Subindu Kumar,et al.  Impact of elliptical cross-section on the propagation delay of multi-channel gate-all-around MOSFET based inverters , 2013, Microelectron. J..

[7]  Gerhard Klimeck,et al.  Valence band effective-mass expressions in the sp 3 d 5 s * empirical tight-binding model applied to a Si and Ge parametrization , 2004 .

[8]  Z. Stanojevic,et al.  Electronic band structure modeling in strained Si-nanowires: Two band k · p versus tight binding , 2010, 2010 14th International Workshop on Computational Electronics.

[9]  Zhiping Yu,et al.  Scaling Theory for FinFETs Based on 3-D Effects Investigation , 2007, IEEE Transactions on Electron Devices.

[10]  A. Tasch,et al.  Experimental determination of threshold voltage shifts due to quantum mechanical effects in MOS electron and hole inversion layers , 1997, IEEE Electron Device Letters.

[11]  S. Selberherr,et al.  Simulation of the Impact of Ionized Impurity Scattering on the Total Mobility in Si Nanowire Transistors , 2019, Materials.

[12]  Andrew R. Brown,et al.  Simulation Study of the Impact of Quantum Confinement on the Electrostatically Driven Performance of n-type Nanowire Transistors , 2015, IEEE Transactions on Electron Devices.

[13]  O. Faynot,et al.  FDSOI CMOS devices featuring dual strained channel and thin BOX extendable to the 10nm node , 2014, 2014 IEEE International Electron Devices Meeting.

[14]  F. Gámiz,et al.  Surface roughness scattering model for arbitrarily oriented silicon nanowires , 2011 .

[15]  G. Ghibaudo,et al.  Unexpected mobility degradation for very short devices : A new challenge for CMOS scaling , 2006, 2006 International Electron Devices Meeting.

[16]  A. Asenov,et al.  Study of the 1D Scattering Mechanisms' Impact on the Mobility in Si Nanowire Transistors , 2018, 2018 Joint International EUROSOI Workshop and International Conference on Ultimate Integration on Silicon (EUROSOI-ULIS).

[17]  H. Kosina,et al.  Atomistic simulations of low-field mobility in Si nanowires: Influence of confinement and orientation , 2011, 1108.4866.

[18]  Asen Asenov,et al.  NESS: new flexible Nano-Electronic Simulation Software , 2018, 2018 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD).

[19]  Lin Li,et al.  Modeling Short-Channel Effect of Elliptical Gate-All-Around MOSFET by Effective Radius , 2011, IEEE Electron Device Letters.

[20]  M. Anantram,et al.  Two-dimensional quantum mechanical modeling of nanotransistors , 2001, cond-mat/0111290.

[21]  M. Fischetti,et al.  Simulation of Silicon Nanowire Transistors Using Boltzmann Transport Equation Under Relaxation Time Approximation , 2008, IEEE Transactions on Electron Devices.

[22]  Miss A.O. Penney.  (b) , 1974, The New Yale Book of Quotations.

[23]  L. Selmi,et al.  Nanoscale MOS Transistors , 2010 .

[24]  Asen Asenov,et al.  Comprehensive study of cross-section dependent effective masses for silicon based gate-all-around transistors , 2019 .

[25]  Yuan Taur,et al.  Scaling of Nanowire Transistors , 2008, IEEE Transactions on Electron Devices.

[26]  A. Asenov,et al.  One-dimensional multi-subband Monte Carlo simulation of charge transport in Si nanowire transistors , 2016, 2016 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD).

[27]  Chih-Hong Hwang,et al.  The effect of the geometry aspect ratio on the silicon ellipse-shaped surrounding- gate field-effect transistor and circuit , 2009 .

[28]  D. Esseni,et al.  A Quantitative Error Analysis of the Mobility Extraction According to the Matthiessen Rule in Advanced MOS Transistors , 2011, IEEE Transactions on Electron Devices.