Dresden 2009 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 28: ZnO: preparation and characterization I
HL 28.5: Vortrag
Mittwoch, 25. März 2009, 10:45–11:00, BEY 118
Growth of ZnO thin films on lattice matched GaN buffered sapphire substrates using pulsed laser interval deposition with in-situ RHEED — •Alexander Hirsch1, Christian Wille1, Frank Ludwig1, Meinhard Schilling1, Uwe Rossow2, and Andreas Hangleiter2 — 1TU Braunschweig, Institut für Elektrische Messtechnik und Grundlagen der Elektrotechnik, Hans-Sommer-Straße 66, D-38106 Braunschweig, Germany — 2TU Braunschweig, Institut für Angewandte Physik, Mendelssohnstraße 2, D-38106 Braunschweig
Due to its wide and direct band gap ZnO is an interesting oxide semiconducting material. Nevertheless, p-type doping with long time stability remains difficult. One way to overcome the doping problem is to use n-type doped ZnO in combination with p-type doped GaN. Therefore, we have studied the pulsed laser deposition (PLD) growth of ZnO thin films on lattice matched GaN buffered Al2O3 substrates.
The target was prepared by standard ceramics synthesis. To achieve lattice matching to ZnO GaN was grown on top of the Al2O3-substrates using MOVPE. The ZnO thin films were grown using a PLD setup equipped with a high-pressure reflection high energy electron diffraction (RHEED) for in-situ investigation of the thin film quality. The structural investigation was supplemented by XRD and AFM.
The influence of the growth temperature and the effect of interval deposition on the thin film quality was analyzed. RHEED intensity oscillations have been observed. Best results are achieved using high temperatures and the technique of interval deposition. These conditions lead to high quality crystalline films with roughnesses <1 nm.