Preparation of gallium nitride surfaces for atomic layer deposition of aluminum oxide

Journal Article · Sun Sep 14 04:00:00 EDT 2014 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4894541· OSTI ID:22308385

Kerr, A. J. ^[1]; Chagarov, E.; Kaufman-Osborn, T.; Gu, S.; Wu, J.; Asbeck, P. M. ^[1]; Madisetti, S.; Oktyabrsky, S. ^[2]

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1. Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92093 (United States)
2. Department of Nanoscale Science and Engineering, University at Albany–State University of New York, Albany, New York 12222 (United States)

A combined wet and dry cleaning process for GaN(0001) has been investigated with XPS and DFT-MD modeling to determine the molecular-level mechanisms for cleaning and the subsequent nucleation of gate oxide atomic layer deposition (ALD). In situ XPS studies show that for the wet sulfur treatment on GaN(0001), sulfur desorbs at room temperature in vacuum prior to gate oxide deposition. Angle resolved depth profiling XPS post-ALD deposition shows that the a-Al{sub 2}O{sub 3} gate oxide bonds directly to the GaN substrate leaving both the gallium surface atoms and the oxide interfacial atoms with XPS chemical shifts consistent with bulk-like charge. These results are in agreement with DFT calculations that predict the oxide/GaN(0001) interface will have bulk-like charges and a low density of band gap states. This passivation is consistent with the oxide restoring the surface gallium atoms to tetrahedral bonding by eliminating the gallium empty dangling bonds on bulk terminated GaN(0001)

• OSTI ID: 22308385
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 10 Vol. 141; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ALUMINIUM OXIDES
ATOMS
CHEMICAL SHIFT
DENSITY
DEPOSITION
GALLIUM
GALLIUM NITRIDES
NUCLEATION
SIMULATION
SUBSTRATES
SURFACES
X-RAY PHOTOELECTRON SPECTROSCOPY