Sadi, T., Medina Bailon, C., Nedjalkov, M., Lee, J., Badami, O., Berrada, S., Carrillo-Nunez, H., Georgiev, V. , Selberherr, S. and Asenov, A. (2019) Simulation of the impact of ionized impurity scattering on the total mobility in Si nanowire transistors. Materials, 12(1), 124. (doi: 10.3390/ma12010124)
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Abstract
Nanowire transistors (NWTs) are being considered as possible candidates for replacing FinFETs, especially for CMOS scaling beyond the 5-nm node, due to their better electrostatic integrity. Hence, there is an urgent need to develop reliable simulation methods to provide deeper insight into NWTs' physics and operation, and unlock the devices' technological potential. One simulation approach that delivers reliable mobility values at low-field near-equilibrium conditions is the combination of the quantum confinement effects with the semi-classical Boltzmann transport equation, solved within the relaxation time approximation adopting the Kubo⁻Greenwood (KG) formalism, as implemented in this work. We consider the most relevant scattering mechanisms governing intraband and multi-subband transitions in NWTs, including phonon, surface roughness and ionized impurity scattering, whose rates have been calculated directly from the Fermi's Golden rule. In this paper, we couple multi-slice Poisson⁻Schrödinger solutions to the KG method to analyze the impact of various scattering mechanisms on the mobility of small diameter nanowire transistors. As demonstrated here, phonon and surface roughness scattering are strong mobility-limiting mechanisms in NWTs. However, scattering from ionized impurities has proved to be another important mobility-limiting mechanism, being mandatory for inclusion when simulating realistic and doped nanostructures, due to the short range Coulomb interaction with the carriers. We also illustrate the impact of the nanowire geometry, highlighting the advantage of using circular over square cross section shapes.
Item Type: | Articles |
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Additional Information: | This work was supported by the European Union’s Horizon 2020 research and innovation programme under grant agreement No 688101, within the SUPERAID7 project. |
Status: | Published |
Refereed: | Yes |
Glasgow Author(s) Enlighten ID: | Carrillo-Nunez, Dr Hamilton and Asenov, Professor Asen and Lee, Mr Jaehyun and Berrada, Dr Salim and Medina Bailon, Miss Cristina and Badami, Mr Oves and Georgiev, Professor Vihar and Sadi, Dr Toufik |
Authors: | Sadi, T., Medina Bailon, C., Nedjalkov, M., Lee, J., Badami, O., Berrada, S., Carrillo-Nunez, H., Georgiev, V., Selberherr, S., and Asenov, A. |
College/School: | College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering |
Journal Name: | Materials |
Publisher: | MDPI |
ISSN: | 1996-1944 |
ISSN (Online): | 1996-1944 |
Copyright Holders: | Copyright © 2019 The Authors |
First Published: | First published in Materials 12(1):124 |
Publisher Policy: | Reproduced under a Creative Commons License |
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