Berlin 2015 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 96: Poster III C (III-V Semiconductors incl. Nitrides)

HL 96.16: Poster

Thursday, March 19, 2015, 14:00–20:00, Poster B

Achieving step flow AlN growth by MOVPE — •Konrad Bellmann, Tim Wernicke, Markus Pristovsek, Frank Mehnke, Christian Kuhn, and Michael Kneissl — Technische Universität Berlin, Institute of Solid State Physics, Secretariat EW6-1, Hardenbergstrasse 36, 10623 Berlin, Germany

Wide bandgap devices based on nitride materials like UVC-LEDs and GaN QDs rely on smooth AlN base layers. Depending on the growth conditions the surface morphologies of AlN layers can vary between step bunches, step flow or spiral hillocks. The V/III ratio during growth has an important impact on the surface reconstruction resulting in a change in surface energy. This work will present a systematic study of AlN growth by metal organic vapor phase epitaxy(MOVPE). The growth of AlN at 1080 ^∘C is investigated for different V/III ratios from 15 to 250. Depending on the V/III ratio a clear transition in surface morphology can be observed. For high V/III ratios AlN growth exhibits spiral growth. At low V/III ratio smooth surfaces with step flow growth are obtained. The data is interpreted with a kinetic model considering the balance between terraces width and diffusion length.