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Core-shell tfet developments and tfet limitations

Passlack, M.; Ramvall, P. LU ; Vasen, T.; Afzalian, A.; Thelander, C. LU ; Dick, K. A. LU ; Wernersson, L. E. LU ; Doornbos, G. and Holland, M. (2019) 2019 International Symposium on VLSI Technology, Systems and Application, VLSI-TSA 2019
Abstract

Tunneling field-effect transistors (TFET) based on a vertical gate-All-Around (VGAA) nanowire (NW) architecture with a core-shell (CS) structure have been explored for future CMOS applications. Performance predictions based on a tight-binding mode-space NEGF technique include a drive current \mathrm{I}-{\mathrm{o}\mathrm{n}} of 6.7\ \mu \mathrm{A} (NW diameter \mathrm{d}= 10.2\ \mathrm{nm}) at \mathrm{V}-{\mathrm{dd}}=0.3\ \mathrm{V} under low power (LP) conditions (\mathrm{I}-{\mathrm{off}}=1 \mathrm{pA}) for an InAs/GaSb CS TFET. This compares to Si nMOSFET \mathrm{I}-{\mathrm{on}} =2.3\ \mu \mathrm{A} at \mathrm{V}-{\mathrm{dd}}=0.55\ \mathrm{V}(\mathrm{d}=6\ \mathrm{nm}). On the experimental side, scaling of vertical CS NWs resulted... (More)

Tunneling field-effect transistors (TFET) based on a vertical gate-All-Around (VGAA) nanowire (NW) architecture with a core-shell (CS) structure have been explored for future CMOS applications. Performance predictions based on a tight-binding mode-space NEGF technique include a drive current \mathrm{I}-{\mathrm{o}\mathrm{n}} of 6.7\ \mu \mathrm{A} (NW diameter \mathrm{d}= 10.2\ \mathrm{nm}) at \mathrm{V}-{\mathrm{dd}}=0.3\ \mathrm{V} under low power (LP) conditions (\mathrm{I}-{\mathrm{off}}=1 \mathrm{pA}) for an InAs/GaSb CS TFET. This compares to Si nMOSFET \mathrm{I}-{\mathrm{on}} =2.3\ \mu \mathrm{A} at \mathrm{V}-{\mathrm{dd}}=0.55\ \mathrm{V}(\mathrm{d}=6\ \mathrm{nm}). On the experimental side, scaling of vertical CS NWs resulted in smallest dimensions of \mathrm{d}-{\mathrm{c}}= 17 nm (GaSb core) and \mathrm{t}-{\mathrm{sh}}=3 nm (InAs shell) for a total diameter of 23 nm. VGAA CS nFETs demonstrated drive current of up to 40\ \mu \mathrm{A} (\mathrm{V}-{\mathrm{d}}=0.3\ \mathrm{V}) and subthreshold swing \mathrm{SS}=40\mathrm{mV}/\mathrm{dec}(\mathrm{V}-{\mathrm{d}}=10\mathrm{mV}) for NW diameters between 35-50 nm. Although key TFET properties such as current drive and subthermal SS have been demonstrated using a VGAA CS architecture for the first time, experimental results still lag predictions. An intrinsic relationship between band-To band-Tunneling (BTBT) and \mathrm{D}-{\mathrm{it}} related trap assisted tunneling (TAT) was found which imposes challenging \mathrm{D}-{\mathrm{it}} requirements, in particular for LP \mathrm{I}-{\mathrm{off}} specifications. Complexity of fabrication and a material system foreign to CMOS manufacturing further impact prospects of TFET technology.

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author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
host publication
2019 International Symposium on VLSI Technology, Systems and Application, VLSI-TSA 2019
publisher
Institute of Electrical and Electronics Engineers Inc.
conference name
2019 International Symposium on VLSI Technology, Systems and Application, VLSI-TSA 2019
conference location
Hsinchu, Taiwan, Province of China
conference dates
2019-04-22 - 2019-04-25
external identifiers
  • scopus:85072106840
ISBN
9781728109428
DOI
10.1109/VLSI-TSA.2019.8804674
language
English
LU publication?
yes
id
d1c4b8e6-152d-4c2f-a756-e91a5e574fe1
date added to LUP
2019-10-11 14:42:49
date last changed
2019-10-15 07:18:43
@inproceedings{d1c4b8e6-152d-4c2f-a756-e91a5e574fe1,
  abstract     = {<p>Tunneling field-effect transistors (TFET) based on a vertical gate-All-Around (VGAA) nanowire (NW) architecture with a core-shell (CS) structure have been explored for future CMOS applications. Performance predictions based on a tight-binding mode-space NEGF technique include a drive current \mathrm{I}-{\mathrm{o}\mathrm{n}} of 6.7\ \mu \mathrm{A} (NW diameter \mathrm{d}= 10.2\ \mathrm{nm}) at \mathrm{V}-{\mathrm{dd}}=0.3\ \mathrm{V} under low power (LP) conditions (\mathrm{I}-{\mathrm{off}}=1 \mathrm{pA}) for an InAs/GaSb CS TFET. This compares to Si nMOSFET \mathrm{I}-{\mathrm{on}} =2.3\ \mu \mathrm{A} at \mathrm{V}-{\mathrm{dd}}=0.55\ \mathrm{V}(\mathrm{d}=6\ \mathrm{nm}). On the experimental side, scaling of vertical CS NWs resulted in smallest dimensions of \mathrm{d}-{\mathrm{c}}= 17 nm (GaSb core) and \mathrm{t}-{\mathrm{sh}}=3 nm (InAs shell) for a total diameter of 23 nm. VGAA CS nFETs demonstrated drive current of up to 40\ \mu \mathrm{A} (\mathrm{V}-{\mathrm{d}}=0.3\ \mathrm{V}) and subthreshold swing \mathrm{SS}=40\mathrm{mV}/\mathrm{dec}(\mathrm{V}-{\mathrm{d}}=10\mathrm{mV}) for NW diameters between 35-50 nm. Although key TFET properties such as current drive and subthermal SS have been demonstrated using a VGAA CS architecture for the first time, experimental results still lag predictions. An intrinsic relationship between band-To band-Tunneling (BTBT) and \mathrm{D}-{\mathrm{it}} related trap assisted tunneling (TAT) was found which imposes challenging \mathrm{D}-{\mathrm{it}} requirements, in particular for LP \mathrm{I}-{\mathrm{off}} specifications. Complexity of fabrication and a material system foreign to CMOS manufacturing further impact prospects of TFET technology.</p>},
  author       = {Passlack, M. and Ramvall, P. and Vasen, T. and Afzalian, A. and Thelander, C. and Dick, K. A. and Wernersson, L. E. and Doornbos, G. and Holland, M.},
  isbn         = {9781728109428},
  language     = {eng},
  location     = {Hsinchu, Taiwan, Province of China},
  publisher    = {Institute of Electrical and Electronics Engineers Inc.},
  title        = {Core-shell tfet developments and tfet limitations},
  url          = {http://dx.doi.org/10.1109/VLSI-TSA.2019.8804674},
  year         = {2019},
}