Recent measurements on atomic-scale dopant wires in Si
Transport in atomic-scale doped silicon nanowiresBent Weber1, S.
Mahapatra1,2, W, Clarke1, M. Y. Simmons1,2 1) School of Physics,
The University of New South Wales, Sydney, NSW 2052, Australia2)
Australian Research Counsel Centre of Excellence for Quantum
Computer Technology, Sydney, Australia
H. Ryu, S. Lee, G. KlimeckNetwork for Computational
Nanotechnology, Purdue University, West Lafayette, IN 47907,
USA
L. C. L. HollenbergCenter for Quantum Computer Technology,
School of Physics, University of Melbourne, VIC 3010, Australia
1Applications of Silicon Nanowires
In-plane gates / leads for silicon donor-based quantum
computingSilicon nanowire transistors
Fuhrer et al.,NanoLetters 9 (2), 707 (2009)Fuechsle et al., Nat.
Nanotech., advance online publication (2010)
SiNWoxidepoly gate5 nm
Singh et al., IEEE Electron Device Letters 27 (5), 383
(2006)
Cui et al., NanoLetters 3 (2), 149 (2003)2As the diameter
reaches the nano-scale:Surface scattering (< 4 nm)Carrier
depletion due to surface/interface statesDoping challengingLimited
to (~ 1020 cm-3) (VLS)Dopant-segregation (< 5 nm)Quantum
confinement ( NMott ~ 3 x 1018 cm-3
Atomistic Modeling of Si Nanowires
T = 4KElectronic structure modeling with atomistic
representation, using NEMO-3D
PhosphorusSiliconDirection of transportdlith=1.7 nmdleff=3.4
nm
Aeff6
Diarra et al., Phys. Rev. B 75 (4), 045301 (2007)
Diameter-Independent Resistivity
9x10183x10191.5x1020bulk resistivity (T= 4 K)Yamada et al., Jap.
J. Appl. Phys. 28 (12), L2284 (1989)
6 nm
Bjork et al., Nat. Nanotech., 4 (2), 103
(2009)7ConclusionsNarrowest doped silicon nanowires, showing Ohmic
conduction
Diameter-independent resistivity, comparable to bulk value full
dopant activation down to ~2 nm
Atomistic tight-binding calculations (NEMO-3D) to compute
electronic structure
T = 4K
8Thanks to Dr. A. Fuhrer (now IBM Rueschlikon, Switzerland) and
Dr. T.C.G. Reusch (now OSRAM Opto Semiconductors, Regensburg,
Germany)
The UNSW Quantum Electronic Devices group of Prof. A. R .
Hamilton (especially Dr. T. Martin, Dr. O. Klochan, A/Prof A. P.
Micolich)
This work was supported by the Australian Research Council, the
Army Research Office under contract number W911NF-08-1-0527 and the
National Science Foundation (NSF). Computational resources on
nanoHUB.org, NICS, TACC, and Oak Ridge National Lab were
utilized.
9