Valence band structure of ultrathin silicon and germanium channels in metal-oxide-semiconductor field-effect transistors

The ultrathin body (UTB) silicon-on-insulator metal-oxide-semiconductor field-effect transistor MOSFET is promising for sub-50-nm complementary metal-oxide semiconductor technologies. To explore a high-mobility channel for this technology, this paper presents an examination of Si and Ge hole sub-ban...

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Main Authors: Low, Tony, Li, M. F., Yeo, Y. C., Fan, Weijun, Ng, S. T., Kwong, Dim Lee
Other Authors: School of Electrical and Electronic Engineering
Format: Article
Language:English
Published: 2013
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Online Access:https://hdl.handle.net/10356/100790
http://hdl.handle.net/10220/17997
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Institution: Nanyang Technological University
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spelling sg-ntu-dr.10356-1007902020-03-07T14:00:32Z Valence band structure of ultrathin silicon and germanium channels in metal-oxide-semiconductor field-effect transistors Low, Tony Li, M. F. Yeo, Y. C. Fan, Weijun Ng, S. T. Kwong, Dim Lee School of Electrical and Electronic Engineering Electrical and Computer Engineering (ECE) Department, University of Texas Silicon Nano Device Laboratory (SNDL) Electrical and Computer Engineering (ECE) Department, National DRNTU::Engineering::Electrical and electronic engineering::Semiconductors The ultrathin body (UTB) silicon-on-insulator metal-oxide-semiconductor field-effect transistor MOSFET is promising for sub-50-nm complementary metal-oxide semiconductor technologies. To explore a high-mobility channel for this technology, this paper presents an examination of Si and Ge hole sub-band structure in UTB MOSFETs under different surface orientations. The dependence of the hole subband structure on the film thickness (TBody) was also studied in this work. We found that the valence-band mixing in the vicinity of the zone center is strongly dependent on TBody for both Si and Ge, particularly for the <110> surface orientation. This gives rise to the following two phenomena that crucially affect the electrical characteristics of p-MOSFETs: (1) an anomalous increase of quantization mass for <110> Si and Ge surfaces as TBody is scaled below 5 nm. (2) The dependence of energy dispersion and anisotropy on TBody especially for the <110> surface, which advantageously increases hole velocity along the [011] channel as TBody is decreased. The density of states for different surface orientations are also calculated, and show that—for any given surface orientation—Ge has a smaller density of states than Si. The Ge <110> surface has the lowest density of states among the surface orientations considered. Published version 2013-12-02T09:06:38Z 2019-12-06T20:28:19Z 2013-12-02T09:06:38Z 2019-12-06T20:28:19Z 2005 2005 Journal Article Low, T., Li, M. F., Yeo, Y. C., Fan, W., Ng, S. T., & Kwong, D. L. (2005). Valence band structure of ultrathin silicon and germanium channels in metal-oxide-semiconductor field-effect transistors. Journal of Applied Physics, 98(2), 024504. 0021-8979 https://hdl.handle.net/10356/100790 http://hdl.handle.net/10220/17997 10.1063/1.1948528 en Journal of applied physics © 2005 American Institute of Physics. This paper was published in Journal of Applied Physics and is made available as an electronic reprint (preprint) with permission of American Institute of Physics. The paper can be found at the following official DOI: [http://dx.doi.org/10.1063/1.1948528]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law. 8 p. application/pdf
institution Nanyang Technological University
building NTU Library
country Singapore
collection DR-NTU
language English
topic DRNTU::Engineering::Electrical and electronic engineering::Semiconductors
spellingShingle DRNTU::Engineering::Electrical and electronic engineering::Semiconductors
Low, Tony
Li, M. F.
Yeo, Y. C.
Fan, Weijun
Ng, S. T.
Kwong, Dim Lee
Valence band structure of ultrathin silicon and germanium channels in metal-oxide-semiconductor field-effect transistors
description The ultrathin body (UTB) silicon-on-insulator metal-oxide-semiconductor field-effect transistor MOSFET is promising for sub-50-nm complementary metal-oxide semiconductor technologies. To explore a high-mobility channel for this technology, this paper presents an examination of Si and Ge hole sub-band structure in UTB MOSFETs under different surface orientations. The dependence of the hole subband structure on the film thickness (TBody) was also studied in this work. We found that the valence-band mixing in the vicinity of the zone center is strongly dependent on TBody for both Si and Ge, particularly for the <110> surface orientation. This gives rise to the following two phenomena that crucially affect the electrical characteristics of p-MOSFETs: (1) an anomalous increase of quantization mass for <110> Si and Ge surfaces as TBody is scaled below 5 nm. (2) The dependence of energy dispersion and anisotropy on TBody especially for the <110> surface, which advantageously increases hole velocity along the [011] channel as TBody is decreased. The density of states for different surface orientations are also calculated, and show that—for any given surface orientation—Ge has a smaller density of states than Si. The Ge <110> surface has the lowest density of states among the surface orientations considered.
author2 School of Electrical and Electronic Engineering
author_facet School of Electrical and Electronic Engineering
Low, Tony
Li, M. F.
Yeo, Y. C.
Fan, Weijun
Ng, S. T.
Kwong, Dim Lee
format Article
author Low, Tony
Li, M. F.
Yeo, Y. C.
Fan, Weijun
Ng, S. T.
Kwong, Dim Lee
author_sort Low, Tony
title Valence band structure of ultrathin silicon and germanium channels in metal-oxide-semiconductor field-effect transistors
title_short Valence band structure of ultrathin silicon and germanium channels in metal-oxide-semiconductor field-effect transistors
title_full Valence band structure of ultrathin silicon and germanium channels in metal-oxide-semiconductor field-effect transistors
title_fullStr Valence band structure of ultrathin silicon and germanium channels in metal-oxide-semiconductor field-effect transistors
title_full_unstemmed Valence band structure of ultrathin silicon and germanium channels in metal-oxide-semiconductor field-effect transistors
title_sort valence band structure of ultrathin silicon and germanium channels in metal-oxide-semiconductor field-effect transistors
publishDate 2013
url https://hdl.handle.net/10356/100790
http://hdl.handle.net/10220/17997
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