Berlin 2005 – wissenschaftliches Programm

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DS: Dünne Schichten

DS 24: Postersitzung II

DS 24.15: Poster

Dienstag, 8. März 2005, 17:00–19:00, Poster TU B

Surface and layer properties of MOVPE-grown InN — •S. J. Simon¹, R. Ehlert¹, M. Drago¹, C. Werner¹, N. Esser², P. Vogt¹, and W. Richter¹ — ¹TU Berlin, Institut für Festkörperphysik, TU Berlin, Hardenbergstr. 36, 10623 Berlin — ²Institute for Analytical Sciences, Department Berlin, Albert-Einstein Str. 9, 12489 Berlin

The formation of indium clusters/droplets and the incorporation of oxygen in InN films during growth is still an open question. Here, we study epitaxial InN layers with thickness between 20 nm and 350 nm MOVPE-grown on sapphire substrates using ammonia and trimethylindium as precursors. Atomic force microscopy images indicate closed layers and x-ray diffraction (XRD) confirms crystalline perfection of the films.

The InN samples are studied in Ultra High Vacuum after surface deoxidation by annealing at approximately 450^∘C. Surface and layer properties are investigated by soft x-ray photoemission spectroscopy (SXPS), scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). The formation of suspected In cluster or droplets in the films and the incorporation of oxygen is analyzed by SXPS. Variations of the fundamental bandgap energy are determined by STS.