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conferenceseries .com
November 13-15, 2017 | Las Vegas, USA
14th International Conference and Exhibition on
Materials Science and Engineering
RRJOMS | Volume 5 | Issue 7 | November, 2017
Effect of TMAl pretreatment of sapphire substrate on the properties of MOCVD grown AlN epilayers
Talal M Al tahtamouni1, Haiding Sun2, Feng Wu2, Nasir Alfaraj2, Kuang-Hui Li2, Xiaohang Li2, Young Jae Park3,Theeradetch Detchprohm3, Russell D. Dupuis3
1Qatar University, Qatar
2 King Abdullah University of Science and Technology, Saudi Arabia
3Georgia Institute of Technology, USA
The growth of high quality AlN epitaxial films relies on precise control of the initial growth stages. In this work, we investigated
the influence of trimethylaluminum (TMAl) pretreatment of sapphire substrates on the properties, impurity incorporation and
growth mode change of AlN films grown by metalorganic chemical vapor deposition (MOCVD). Without the pretreatment, no trace
of carbon was found at AlN/sapphire interface and the residual oxygen resulted in N-polarity. With 5s pretreatments, carbon started
to be incorporated, forming scattered carbon-rich zones due to the decomposition of TMAl. It was discovered that carbon attracted
surrounding oxygen impurity atoms and consequently, suppressed the formation of N-polarity. With 40 s pretreatment, a significant
presence of carbon clusters at the AlN/sapphire interface occurred, which attracted considerable co-existed oxygen. While preventing
the N-polarity, the carbon clusters served as randommasks to further induce a 3D growth mode, creating Al-polar AlN nanocolumns
with different facets. The properties of AlN and epitaxial growth mode change are discussed
Biography
Prof. Al tahtamouni is an associate professor at Department of Material Science and Technology in Qatar University. His research mainly concentrates on design, material
growth and property study of III-nitride-based deep UV optoelectronic devices. He conducted the research on design, growth and testing of deep-UV light-emitting diodes
(LEDs) and MOCVD growth of polar and nonpolar Group-III nitrides epilayers and quantum well structures. He also received many awards and honors, such as DFG Fel-
lowship Research grant at Ulm University and Fulbright Research Award at Texas Tech University. Al tahtamouni's research work on deep ultra violet materials and device
structures resulted in a series of technical publications in the world leading journals and conferences. Many of his papers have been published in Applied Physics Letters,
widely considered one of the top international journals in this research area.
Talal M Al tahtamouni et al., Res. Rev. J Mat. Sci. 2017, 5:7
DOI: 10.4172/2321-6212-C1-011