Schottky contact formation on polar and non-polar AlN

Reddy, Pramod; Bryan, Isaac; Bryan, Zachary; Tweedie, James; Kirste, Ronny; Collazo, Ramon; Sitar, Zlatko

doi:10.1063/1.4901954

Schottky contact formation on polar and non-polar AlN

Journal Article · Tue Nov 18 04:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4901954· OSTI ID:1420474

; Bryan, Isaac; Bryan, Zachary; Tweedie, James; Kirste, Ronny; Collazo, Ramon; Sitar, Zlatko

The interfaces of m- and c-plane AlN with metals of different work functions and electro-negativities were characterized and the Schottky barrier heights were measured. The Schottky barrier height was determined by measuring the valence band maximum (VBM) with respect to the Fermi level at the surface (interface) before (after) metallization. VBM determination included accurate modeling and curve fitting of density of states at the valence band edge with the XPS data. The experimental behavior of the barrier heights could not be explained by the Schottky-Mott model and was modeled using InterFace-Induced Gap States (IFIGS). A slope parameter (SX) was used to incorporate the density of surface states and is a measure of Fermi level pinning. The experimental barriers followed theoretical predictions with a barrier height at the surface Fermi level (Charge neutrality level (CNL)) of ∼2.1 eV (∼2.7 eV) on m-plane (c-plane) and SX ∼ 0.36 eV/Miedema unit. Slope parameter much lower than 0.86 implied a surface/interface states dominated behavior with significant Fermi level pinning and the measured barrier heights were close to the CNL. Titanium and zirconium provided the lowest barriers (1.6 eV) with gold providing the highest (2.3 eV) among the metals analyzed on m-plane. It was consistently found that barrier heights decreased from metal polar to non-polar surfaces, in general, due to an increasing CNL. The data indicated that charged IFIGS compensate spontaneous polarization charge. These barrier height and slope parameter measurements provided essential information for designing Schottky diodes and other contact-based devices on AlN.

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Sponsoring Organization:: USDOE Advanced Research Projects Agency - Energy (ARPA-E)

Grant/Contract Number:: AR0000299

OSTI ID:: 1420474

Alternate ID(s):: OSTI ID: 1211341
OSTI ID: 22402679

Journal Information:: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 19 Vol. 116; ISSN 0021-8979

Publisher:: American Institute of PhysicsCopyright Statement

Country of Publication:: United States

Language:: English

References (23)

Ni/Au Schottky diodes on AlxGa1-xN (0.7 Xie, Jinqiao; Mia, Seiji; Dalmau, Rafael physica status solidi (c), Vol. 8, Issue 7-8 https://doi.org/10.1002/pssc.201001009	journal	June 2011
Schottky barrier and interface chemistry for Ni contacted to Al0.8Ga0.2N grown on c-oriented AlN single crystal substrates Tweedie, James; Collazo, Ramón; Rice, Anthony physica status solidi (c), Vol. 9, Issue 3-4 https://doi.org/10.1002/pssc.201100435	journal	January 2012
Negative electron affinity surfaces of aluminum nitride and diamond Nemanich, R. J.; Baumann, P. K.; Benjamin, M. C. Diamond and Related Materials, Vol. 5, Issue 6-8 https://doi.org/10.1016/0925-9635(95)00485-8	journal	May 1996
A review of the metal–GaN contact technology Liu, Q. Z.; Lau, S. S. Solid-State Electronics, Vol. 42, Issue 5 https://doi.org/10.1016/S0038-1101(98)00099-9	journal	May 1998
Seeded growth of AlN on N- and Al-polar AlN seeds by physical vapor transport Herro, Z. G.; Zhuang, D.; Schlesser, R. Journal of Crystal Growth, Vol. 286, Issue 2 https://doi.org/10.1016/j.jcrysgro.2005.10.074	journal	January 2006
Seeded growth of AlN single crystals by physical vapor transport Zhuang, D.; Herro, Z. G.; Schlesser, R. Journal of Crystal Growth, Vol. 287, Issue 2, p. 372-375 https://doi.org/10.1016/j.jcrysgro.2005.11.047	journal	January 2006
Seeded growth of AlN bulk crystals in m- and c-orientation Lu, P.; Collazo, R.; Dalmau, R. F. Journal of Crystal Growth, Vol. 312, Issue 1 https://doi.org/10.1016/j.jcrysgro.2009.10.008	journal	December 2009
Formation and Schottky barrier height of metal contacts to β‐SiC Waldrop, J. R.; Grant, R. W. Applied Physics Letters, Vol. 56, Issue 6 https://doi.org/10.1063/1.102744	journal	February 1990
Metal contacts to gallium nitride Foresi, J. S.; Moustakas, T. D. Applied Physics Letters, Vol. 62, Issue 22 https://doi.org/10.1063/1.109207	journal	May 1993
Low resistance ohmic contacts on wide band‐gap GaN Lin, M. E.; Ma, Z.; Huang, F. Y. Applied Physics Letters, Vol. 64, Issue 8 https://doi.org/10.1063/1.111961	journal	February 1994
Electron affinity at aluminum nitride surfaces Wu, C. I.; Kahn, A.; Hellman, E. S. Applied Physics Letters, Vol. 73, Issue 10 https://doi.org/10.1063/1.122158	journal	September 1998
Electrical, thermal, and microstructural characteristics of Ti/Al/Ti/Au multilayer Ohmic contacts to n-type GaN Motayed, Abhishek; Bathe, Ravi; Wood, Mark C. Journal of Applied Physics, Vol. 93, Issue 2 https://doi.org/10.1063/1.1528294	journal	January 2003
Formation of vanadium-based ohmic contacts to n-GaN Song, June O.; Kim, Sang-Ho; Kwak, Joon Seop Applied Physics Letters, Vol. 83, Issue 6 https://doi.org/10.1063/1.1598284	journal	August 2003
Vanadium-based Ohmic contacts to n-AlGaN in the entire alloy composition France, Ryan; Xu, Tao; Chen, Papo Applied Physics Letters, Vol. 90, Issue 6 https://doi.org/10.1063/1.2458399	journal	February 2007
Surface preparation and homoepitaxial deposition of AlN on (0001)-oriented AlN substrates by metalorganic chemical vapor deposition Rice, A.; Collazo, R.; Tweedie, J. Journal of Applied Physics, Vol. 108, Issue 4 https://doi.org/10.1063/1.3467522	journal	August 2010
Strain in Si doped GaN and the Fermi level effect Xie, Jinqiao; Mita, Seiji; Rice, Anthony Applied Physics Letters, Vol. 98, Issue 20 https://doi.org/10.1063/1.3589978	journal	May 2011
The growth and properties of Al and AlN films on GaN(0001)–(1×1) Bermudez, V. M.; Jung, T. M.; Doverspike, K. Journal of Applied Physics, Vol. 79, Issue 1 https://doi.org/10.1063/1.360917	journal	January 1996
Strain relaxation by pitting in AlN thin films deposited by metalorganic chemical vapor deposition Bryan, I.; Rice, A.; Hussey, L. Applied Physics Letters, Vol. 102, Issue 6 https://doi.org/10.1063/1.4792694	journal	February 2013
The effect of polarity and surface states on the Fermi level at III-nitride surfaces Reddy, Pramod; Bryan, Isaac; Bryan, Zachary Journal of Applied Physics, Vol. 116, Issue 12 https://doi.org/10.1063/1.4896377	journal	September 2014
Interface chemistry of metal‐GaAs Schottky‐barrier contacts Waldrop, J. R.; Grant, R. W. Applied Physics Letters, Vol. 34, Issue 10 https://doi.org/10.1063/1.90642	journal	May 1979
Role of photocurrent in low-temperature photoemission studies of Schottky-barrier formation Hecht, M. H. Physical Review B, Vol. 41, Issue 11 https://doi.org/10.1103/PhysRevB.41.7918	journal	April 1990
Band bending and photoemission-induced surface photovoltages on clean n - and p -GaN (0001) surfaces Long, J. P.; Bermudez, V. M. Physical Review B, Vol. 66, Issue 12 https://doi.org/10.1103/PhysRevB.66.121308	journal	September 2002
Reconstructions and origin of surface states on AlN polar and nonpolar surfaces Miao, M. S.; Janotti, A.; Van de Walle, C. G. Physical Review B, Vol. 80, Issue 15 https://doi.org/10.1103/PhysRevB.80.155319	journal	October 2009

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