Regensburg 2007 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 46: Poster 2

HL 46.23: Poster

Thursday, March 29, 2007, 15:00–17:30, Poster A

Annealing of implantation defects in GaN by swift heavy ion irradiation — Anne-Katrin Nix¹, Sven Müller¹, Carsten Ronning¹, Andrey Kamarou², Elke Wendler², Werner Wesch², Christina Trautmann³, and •Hans Hofsäss¹ — ¹II. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany — ²Institut für Festkörperphysik, Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany — ³Gesellschaft für Schwerionenforschung, Planckstasse 1, 64291 Darmstadt, Germany

Direct implantation of ions into semiconductors for doping allows concentration and depth modelling, but results in lattice defects. Thermal annealing is used for recrystallisation, but surface melting and dopant diffusion hampers the annealing effect. Here, we present an annealing method which can avoid these effects. During ion beam irradiation, the material is locally heated during a timespan of 10-12 seconds, surrounding material stays unaffected. The energy of the ions used for annealing should be in the MeV regime because the resulting nuclear energy loss must be low to avoid cluster formation. In addition to this it is necessary that the resulting electronic energy loss is lower than the threshold value for track formation. Mg ions with 100 keV were implanted into GaN with fluences of 3x10¹³ ions/cm² and 10¹⁴ ions/cm². These samples were irradiated with 578 MeV Cr and 140 MeV Kr, the fluences were 5x10¹¹ ions/cm² and 5x10¹² ions/cm² . 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.