In-situ determination of interface roughness in MOVPE-grown visible VCSELs by reflectance spectroscopy

K. Haberland^a,b, M. Zorn^c, A. Klein^c, A. Bhattacharya^c, M. Weyers^c, J.-T. Zettler^b, W. Richter^a

^aTechnische Universität Berlin, Institut für Festkörperphysik, Sekr. PN 6-1, Hardenbergstr. 36, D-10623 Berlin, Germany
^bLayTec GmbH für in-situ und Nano-Sensorik, Helmholtzstr. 13-14, D-10587 Berlin, Germany
^cFerdinand-Braun-Institut für Höchstfrequenztechnik, Albert-Einstein-Straße 11, D-12489 Berlin, Germany

Published in:
Journal of Crystal Growth 248 (2003) 194-200.
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Abstract:
This paper reports on an in-situ optical reflectance study of the development of the interface roughness of AlGaAs/AlAs distributed Bragg reflectors during the metalorganic vapour phase epitaxy growth of visible vertical-cavity surface-emitting laser structures. We show that the surface roughness can be extracted from time-resolved UV reflectance measurements. The roughness of the surface during growth for both the AlGaAs and AlAs layers can be determined individually. The values estimated from the in-situ optical data correlate well with the roughness measured ex-situ using atomic force microscopy. The in-situ reflectance measurement is thus shown to be a convenient non-invasive and non-destructive technique for determining surface and interface roughness even for complex device structures.

Keywords:
A1. In-situ monitoring; A1. Surface and interface roughness; A3. Metalorganic vapor phase epitaxy; B3. Vertical cavity surface emitting lasers

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