Regensburg 2010 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 45: Group-III-Nitrides: Optical Properties II
HL 45.9: Vortrag
Mittwoch, 24. März 2010, 16:45–17:00, H15
Phase separation in AlGaN layers grown on SiN interlayers — •Kim Juliane Fujan1, Benjamin Neuschl1, Ingo Tischer1, Martin Feneberg1, Klaus Thonke1, Martin Klein2, Kamran Forghani2, and Ferdinand Scholz2 — 1Institut für Halbleiterphysik, Universität Ulm, 89069 Ulm — 2Institut für Optoelektronik, Universität Ulm, 89069 Ulm
For high quality AlGaN templates in-situ SiN interlayers are a possible method to decrease the dislocation density effectively. Immediately after such a SiN layer, the growth re-starts in a 3D-like mode, before the layers smoothen again. We report on a low temperature photoluminescence and cathodoluminescence study with high spatial resolution on a series of such AlGaN layer structures. We find signatures of anisotropic aluminum incorporation efficiency for different facets especially immediately after the interlayer deposition. In cathodoluminescence we directly can spatially resolve this phase separation, which vanishes for layer thicknesses of ∼ 1 µm and more. Influence of layer homogeneity (roughness) and possible growth mechanisms are discussed in detail.