Dresden 2009 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 41: GaN: preparation and characterization II
HL 41.9: Talk
Thursday, March 26, 2009, 12:00–12:15, BEY 154
Swift heavy ion irradiation induced recrystallization of implanted GaN — •Anne-Katrin Nix1, Sven Müller1, Ulrich Vetter1, Christina Trautmann2, and Hans Hofsäss1 — 1II. Physikalisches Institut, Universität Göttingen, Germany — 2Gesellschaft für Schwerionenforschung, Darmstadt, Germany
Preparing GaN:Mg by ion implantation is a widely used technique of doping, but results in a high level of lattice defects. Thermal annealing can be used for recrystallization, but sample decomposition often hampers the annealing effect. Here, we present swift heavy ion irradiation as an alternative annealing method. Due to high electronic energy loss along the ion track, the sample is locally heated during a time span of 10−12 seconds. Thus, surrounding material stays unaffected. Implanted GaN samples were irradiated with several ion species at different energies with the objective to vary the electronic energy loss. Directly after implantation and after irradiation, the photoluminescence excited with a laser emitting in the UV-regime was examined at low temperature. The obtained spectra are compared to well known spectra of GaN and GaN:Mg. An annealing effect is seen after 578 MeV Cr-irradiation. GaN samples were irradiated with 668 MeV Ni-ions with varying fluences, obtaining a similar electronic energy loss compared to 578 MeV Cr-ions, with the goal to examine a fluence dependence of the annealing process. In addition, irradiation with light ions, and thus much lower electronic energy loss, was performed with the aim of analyzing a possible threshold value of the electronic energy loss.