Dresden 2006 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 9: Poster I

HL 9.2: Poster

Montag, 27. März 2006, 15:15–17:45, P3

MOVPE of InN on nitridated sapphire and GaN templates — •M. Drago¹, C. Werner¹, P. Vogt¹, G. Manolis², M. Pristovsek¹, U. W. Pohl¹, M. Kneissl¹, and W. Richter³ — ¹Techn. Univ. Berlin, Institut für Festkörperphysik, Hardenbergstraße 36, 10623 Berlin, Germany — ²Nat. Techn. University of Athens, Dept. of Physics, GR-15780 Athens, Greece — ³Univ. di Roma Torvergata, Dipart. di Fisica, Via della ricerca scientifica 1, I-00133 Rome, Italy

Optimum crystalline quality and defect analysis are still critical issues for InN research. For MOVPE growth on sapphire, substrate nitridation is the key step in order to obtain single crystal InN layers. Here we report studies on sapphire nitridation with ammonia by in-situ spectroscopic ellipsometry (SE). At 1050^∘C, 100 mbar and an ammonia flow of 1 L/min the sapphire surface reacts completely within 45 s, forming an AlN layer about 0.8 nm thick. The influence of sapphire nitridation on the quality of InN layers was assessed ex-situ investigating a set of InN layers grown on sapphire after different nitridation duration. For a 45 s nitridation InN displayed the best morphology, electronic properties and narrowest (00.2) X-Ray reflections. For a duration of 180 s sapphire nitridation (~1.0 nm AlN calculated by SE), the InN (10.2) reflections became narrower. Longer nitridation times led to deterioration of the quality of the InN layers. These results are compared to the growth of InN on GaN templates. SXPS measurements on the InN layers demonstrate no contamination by carbon, but show some traces of oxygen, which influence electronic and optical properties of InN.