Defects induced in GaN by europium implantation

We have investigated structural and electrical properties of defects introduced during room temperature europium implantation into GaN. Two geometries, random and channeled implantation, were used. Rutherford backscattering and channeling analysis reveals that implantation induces a significantly lower concentration of defects, in the case of channeled implantation. These defects generate a perpendicular expansion of the GaN lattice in the implanted region, as evidenced by x-ray diffraction. From deep-level transient spectroscopy, beside intrinsic defects with energy levels below the conduction band, one additional electron trap, labeled Eu2, is observed at an energy (E-c-0.36 eV). It is believed that this defect in n-GaN is europium related. (C) 2004 American Institute of Physics.