Regensburg 2007 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 46: Poster 2

HL 46.59: Poster

Donnerstag, 29. März 2007, 15:00–17:30, Poster A

Influence of buffer layers on the structural properties of ZnO grown by plasma assisted molecular beam epitaxy — •Bernhard Laumer, Thomas Wassner, Stefan Maier, Martin Stutzmann, and Martin Eickhoff — Walter Schottky Institut, Technische Universität München, Am Coulombwall 3, 85748 Garching, Germany

We have investigated the influence of ZnO and MgO buffer layers on the structural properties of ZnO-films heteroepitaxially grown on (0001)- and (11-20)-sapphire substrates by plasma assisted molecular beam epitaxy. The use of a thin buffer layer facilitates the nucleation process on the sapphire substrate and thus allows the growth of ZnO-films at higher substrate temperatures, leading to a higher surface mobility of the adatoms. A systematic high resolution X-ray diffraction study of symmetric and asymmetric reflexes was carried out to analyze the impact of the buffer growth conditions on the structural properties such as the edge- and screw dislocation densities in the deposited ZnO-films. In addition, the effect of offcut-substrates and buffer layer annealing on the structural quality of the ZnO epilayers has been investigated. The influence of the structural properties on the electrical and optical characteristics (luminescence, conductivity, carrier mobility) of the ZnO layers will also be discussed.