Controlled coalescence of MOVPE grown AlN during lateral overgrowth

V. Kuellera, A. Knauera, U. Zeimera, M. Kneissla,b, M. Weyersa

Published in:

J. Cryst. Growth, vol. 368, pp. 83-86 (2013).

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Abstract:

The substrate miscut orientation of c-plane sapphire has an impact on the lateral growth and coalescence of AlN during epitaxial lateral overgrowth of patterned AlN/sapphire templates. A faster and more homogeneous coalescence was observed for substrates with a miscut orientation of 0.25° toward the m-direction compared to 0.25° toward the a-direction of the sapphire. A reduction of V/III ratio during overgrowth leads to an increase of lateral growth rate and therefore to a faster coalescence. The layer thickness at coalescence was clearly determined by in-situ reflectance measurements during the overgrowth. The coalescence can be controlled by carefully choosing the parameters influencing lateral growth like substrate miscut, process temperature and V/III ratio.

a Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, D-12489 Berlin, Germany
b Institute of Solid State Physics, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany

Keywords:

A1. In-situ characterization; A1. Substrate miscut; A3. Metalorganic vapor phase epitaxy; A3. Pendeoepitaxy; A3. V/III ratio; B1. Nitrides.