Ultra-thin-body (UTB) channel materials of a few nanometers in thickness are currently considered as candidates for future electronic, thermoelectric, and optoelectronic applications. Among the features that they possess, which make them attractive for such applications, their confinement length scale, transport direction, and confining surface orientation serve as degrees of freedom for engineering their electronic properties. This work presents a comprehensive study of hole velocities in p-type UTB films of widths from 15 nm down to 3 nm. Various transport and surface orientations are considered. The atomistic sp3d5s*-spin-orbit-coupled tight-binding model is used for the electronic structure, and a semiclassical ballistic model for the carrier velocity calculation. We find that the carrier velocity is a strong function of orientation and layer thickness. The (110) and (112) surfaces provide the highest hole velocities, whereas the (100) surfaces the lowest velocities, almost 30% lower than the best performers. Additionally, up to 35% velocity enhancements can be achieved as the thickness of the (110) or (112) surface channels is scaled down to 3 nm. This originates from strong increase in the curvature of the p-type UTB film subbands with confinement, unlike the case of n-type UTB channels. The velocity behavior directly translates to ballistic on-current trends, and correlates with trends in experimental mobility measurements.

1.
ITRS Public Home Page, available at http://www.itrs.net/reports.html.
2.
L. D.
Hicks
and
M. S.
Dresselhaus
,
Phys. Rev. B
47
,
16631
(
1993
).
3.
S.-M.
Lee
,
D.
Cahill
, and
R.
Venkatasubramanian
,
Appl. Phys. Lett.
70
,
2957
(
1997
).
4.
R.
Venkatasubramanian
,
E.
Siivola
,
T.
Colpitts
, and
B.
O’Quinn
,
Nature
413
,
597
(
2001
).
5.
A. I.
Hochbaum
,
R.
Chen
,
R. D.
Delgado
,
W.
Liang
,
E. C.
Garnett
,
M.
Najarian
,
A.
Majumdar
, and
P.
Yang
,
Nature
451
,
163
(
2008
).
6.
A. I.
Boukai
,
Y.
Bunimovich
,
J. T.
-Kheli
,
J.-K.
Yu
,
W. A.
Goddard III
, and
J. R.
Heath
,
Nature
451
,
168
(
2008
).
7.
C. B.
Winkelmann
,
I.
Ionica
,
X.
Chevalier
,
G.
Royal
,
C.
Bucher
, and
V.
Bouchiat
,
Nano Lett.
7
,
1454
(
2007
).
8.
M.
Law
,
L. E.
Greene
,
J. C.
Johnson
,
R.
Saykally
, and
P.
Yang
,
Nat. Mater.
4
,
455
(
2005
).
9.
S.
Huang
and
Y.
Chen
,
Nano Lett.
8
,
2829
(
2008
).
10.
P. R.
Nair
and
M. A.
Alam
,
Appl. Phys. Lett.
88
,
233121
(
2006
).
11.
Y.
Liu
,
N.
Neophytou
,
T.
Low
,
G.
Klimeck
, and
M. S.
Lundstrom
,
IEEE Trans. Elect. Dev.
55
,
866
(
2008
).
12.
M.
Yang
,
V. W. C.
Chan
,
K. K.
Chan
,
L.
Shi
,
D. M.
Fried
,
J. H.
Stathis
,
A. I.
Chou
,
E.
Gusev
,
J. A.
Ott
,
L. E.
Burns
,
M. V.
Fischetti
, and
M.
Ieong
,
IEEE Trans. Electr. Dev.
53
,
965
(
2006
).
13.
M. V.
Fischetti
,
Z.
Ren
,
P. M.
Solomon
,
M.
Yang
, and
K.
Rim
,
J. Appl. Phys.
94
, (
2003
).
14.
Y.-T.
Huang
,
A.
Pinto
,
C.-T.
Lin
,
C.-H.
Hsu
,
M.
Ramin
,
M.
Seacrist
,
M.
Ries
,
K.
Matthews
,
B.
Nguyen
,
M.
Freeman
,
B.
Wilks
,
C.
Stager
,
C.
Johnson
,
L.
Denning
,
J.
Bennett
,
S.
Joshi
,
S.
Chiang
,
L.-W.
Cheng
,
T.-H.
Lee
,
M.
Ma.
,
O.
Cheng
,
R.
Wise.
,
IEEE Electr. Dev. Lett.
28
, no.
9
, pp.
815
817
(
2007
).
15.
N.
Neophytou
,
S. G.
Kim
,
G.
Klimeck
, and
H.
Kosina
,
J. Appl. Phys.
107
,
113701
(
2010
).
16.
F.
Stern
and
W. E.
Howard
,
Phys. Rev.
163
,
816
(
1967
).
17.
A.
Rahman
,
M. S.
Lundstrom
, and
A. W.
Ghosh
,
J. Appl. Phys.
97
,
053702
(
2005
).
18.
N.
Neophytou
,
A.
Paul
, and
G.
Klimeck
,
IEEE Trans. Nanotechnol.
7
,
710
(
2008
).
19.
N.
Neophytou
and
G.
Klimeck
,
Nano Lett.
9
,
623
(
2009
).
20.
M.
Luisier
and
G.
Klimeck
, in
8th IEEE Conference on Nanotechnology, 2008. NANO’08, 18–21 Aug. 2008
, (
IEEE
New York
,
2008
) pp.
354
357
.
21.
A.
Paul
,
S.
Mehrotra
,
M.
Luisier
and
G.
Klimeck
,
IEEE Elect. Dev. Lett.
31
,
278
(
2010
).
22.
M.
Shin
,
S.
Lee
, and
G.
Klimeck
,
IEEE Trans. Elect. Dev.
57
,
2274
(
2010
).
23.
T. B.
Boykin
,
G.
Klimeck
, and
F.
Oyafuso
,
Phys. Rev. B
69
,
115201
(
2004
).
24.
G.
Klimeck
,
S.
Ahmed
,
H.
Bae
,
N.
Kharche
,
S.
Clark
,
B.
Haley
,
S.
Lee
,
M.
Naumov
,
H.
Ryu
,
F.
Saied
,
M.
Prada
,
M.
Korkusinski
, and
T. B.
Boykin
,
IEEE Trans. Electr. Dev.
54
,
2079
(
2007
).
25.
N.
Neophytou
,
A.
Paul
,
M.
Lundstrom
, and
G.
Klimeck
,
IEEE Trans. Elect. Dev.
55
,
1286
(
2008
).
26.
M. S.
Lundstrom
and
J.
Guo
,
Nanoscale Transistors: Device Physics, Modeling and Simulation
, (
Springer
New York
,
2006
).
27.
A.
Rahman
,
J.
Guo
,
S.
Datta
, and
M.
Lundstrom
,
IEEE Trans. Electr. Dev.
50
,
1853
(
2003
).
28.
L.
Chang
,
M.
Ieong
, and
M.
Yang
,
IEEE Trans. Electr. Dev.
51
,
1621
(
2004
).
29.
J.
Wang
, Ph.D. dissertation,
Purdue University
,
2005
.
30.
N.
Kharche
,
M.
Prada
,
T. B.
Boykin
, and
G.
Klimeck
,
Appl. Phys. Lett.
90
,
092109
(
2007
).
31.
R.
Rahman
,
C. J.
Wellard
,
F. R.
Bradbury
,
M.
Prada
,
J. H.
Cole
,
G.
Klimeck
, and
L. C. L.
Hollenberg
,
Phys. Rev. Lett.
99
,
036403
(
2007
).
32.
K.
Natori
,
J. Appl. Phys.
76
,
4879
(
1994
).
33.
A. K.
Buin
,
A.
Verma
,
A.
Svizhenko
, and
M. P.
Anantram
,
Nano Lett.
8
,
760
(
2008
).
34.
N.
Neophytou
, and
H.
Kosina
,
Nano Lett.
10
,
4913
(
2010
).
35.
S. E.
Thompson
,
M.
Armstrong
,
C.
Auth
,
M.
Alavi
,
M.
Buehler
,
R.
Chau
,
S.
Cea
,
T.
Ghani
,
G.
Glass
,
T.
Hoffman
,
C.-H.
Jan
,
C.
Kenyon
,
J.
Klaus
,
K.
Kuhn
,
M.
Zhiyong
,
B.
Mcintyre
,
K.
Mistry
,
A.
Murthy
,
B.
Obradovic
,
R.
Nagisetty
,
N.
Phi
,
S.
Sivakumar
,
R.
Shaheed
,
L.
Shifren
,
B.
Tufts
,
S.
Tyagi
,
M.
Bohr
,
Y.
El-Mansy
,
IEEE Trans. Electr. Dev.
51
,
1790
(
2004
).
36.
K.
Uchida
and
S.
Takagi
,
IEEE Appl. Phys. Lett.
82
,
2916
(
2003
).
37.
N.
Neophytou
,
A.
Paul
,
M.
Lundstrom
, and
G.
Klimeck
,
Proc. Simul. Semicond. Processes Devices.
12
,
217
(
2007
).
38.
Bandstructure lab on nanoHUB.org, available at https://www.nanohub.org/tools/bandstrlab/.
You do not currently have access to this content.