Regensburg 2019 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 31: Nitrides: Preparation and characterization II

HL 31.3: Vortrag

Mittwoch, 3. April 2019, 15:30–15:45, H31

Towards a Deeper Understanding of Shell Growth on GaN Microstructures — •Irene Manglano Clavero¹, Christoph Margenfeld¹, Jana Hartmann¹, Hergo-Heinrich Wehmann¹, Adrian Avramescu², Hans-Juergen Lugauer², and Andreas Waag¹ — ¹Institut für Halbleitertechnik, epitaxy competence center ec² and Laboratory for Emerging Nanometrology, Technische Universität Braunschweig, Braunschweig, Germany — ²Osram Opto Semiconductors GmbH, Regensburg, Germany

In the last decade, 3D nano and micro light emitting diodes with nonpolar planes have been regarded as promising optical devices to mitigate the droop and provide reduced density of extended defects. Although different groups have investigated the growth mechanism of these 3D structures, there is still no thorough understanding of the mechanisms governing the core-shell growth.

The impact of gallium supply and carrier gas composition on the morphology and growth rate of c- and a-plane shells on GaN microfins grown by selective area metal-organic vapor-phase epitaxy (Sa-MOVPE) are studied. We evaluate the resulting growth rates in terms of a model based on Chapman-Enskog theory of gas phase diffusion and obtain qualitative and quantitative agreement. It is found that shell growth on 3D microstructures deviates significantly from the mass-transport limited regime which is conventionally observed for the planar case, as is concluded from evaluating the sticking coefficients obtained from the model for the polar and nonpolar crystal planes.