Effect of the AIN nucleation layer growth on AlN material quality

O. Reentilä^a, F. Brunner^a, A. Knauer^a, A. Mogilatenko^b, W. Neumann^b, H. Protzmann^c, M. Heuken^c, M. Kneissl^a,d, M. Weyers^a, G. Tränkle^a

^a Ferdinand-Braun-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, D-12489 Berlin, Germany
^b Institute of Physics, Humboldt Universität zu Berlin, Newtonstr. 15, D-12489 Berlin, Germany
^c AIXTRON AG, Kackertstr.15-17, D-52072 Aachen, Germany
^d Institute of Solid State Physics, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin, Germany

Published in:
Journal of Crystal Growth 310 23 (2008) 4932-4934.
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Abstract:
AlN layers were grown by metalorganic vapor-phase epitaxy at high temperatures up to 1500°C. Nucleation layer growth parameters and flow conditions before nucleation were changed and the effect on the AlN layer grown on top was studied. Structural analysis performed by high-resolution X-ray diffractometry and transmission electron microscopy showed that pregrowth conditions affect the material quality drastically. The best structural quality as indicated by a screw (including mixed) dislocation density of 8x10⁸ cm^-2, together with smooth surface morphology was found to result from simultaneous switching on of ammonia and TMA lat the beginning of nucleation layer growth.

Keywords:
A1. High-resolution X-ray diffraction A3. Metalorganic vapor-phase epitaxy B1. Aluminum nitride B1. Nitrides

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