Berlin 2008 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 33: III-V semiconductors II
HL 33.3: Talk
Wednesday, February 27, 2008, 14:45–15:00, EW 201
Swift heavy ion irradiation for recovery from implantation defects of GaN — •Anne-Katrin Nix1, Sven Müller1, Carsten Ronning1, Andrey Kamarou2, Elke Wendler2, Werner Wesch2, Christina Trautmann3, and Hans Hofsäss1 — 1II. Physikalisches Institut, Universität Göttingen, Germany — 2Institut für Festkörperphysik, Friedrich-Schiller Universität, Jena, Germany — 3Gesellschaft für Schwerionenforschung, Darmstadt, Germany
Doping GaN by ion implantation (100 keV Mg-ions) is a desired task for the realization of lateral optoelectronic devices, but results in a high level of lattice defects. Thermal annealing can be used for recrystallisation, but surface melting and dopant diffusion hampers the annealing effect. Here, we present an alternative annealing method. The GaN crystals are irradiated with swift heavy ions, thus, the sample is locally heated during a timespan of 10−12 seconds , surrounding material stays unaffected. Mg ions were implanted into GaN with fluences of 3x1013 ions/cm2 and 1014 ions/cm2. These samples were irradiated with several ion species at different energies (578 MeV Cr, 55 MeV Xe, 140 MeV Kr, 1GeV Xe and 593 MeV Au), thus the electronic energy loss is varied ( 8 keV/nm, 17 keV/nm, 19 keV/nm, 27 keV/nm, 43 keV/nm). Directly after implantation and after irradiation, the photoluminescence was examined at low temperature (12 K), the obtained spectra are compared to well known spectra of GaN and GaN:Mg. For an annealing effect is seen after Cr-irradiation, GaN samples were irradiated with 668 MeV Ni (9 keV/nm) with varying fluences to examine a fluence dependence of the annealing process.