Abstract
AbstractThe effect of Indium (In) implantation in n‐type GaN is studied using Raman spectroscopy and Rutherford backscattering (RBS). The RBS analysis reveals that the 700 keV In implantation results in the formation of a subsurface defective region that extends to a depth of 400 nm. An abrupt increase (∼93%) of the maximum defect concentration is observed for fluences in the range 1.5 and 5×1014 cm‐2. A further increase of the fluence to 5×1015 cm‐2 renders the implanted layer amorphous. In the Raman spectra recorded in the backscattering geometry only the E22 peak is resolved since the A1(LO) is completely damped due to plasmon ‐ phonon coupling. As the fluence increases, the characteristic sharp peaks of the as‐grown sample broaden due to relaxation of the q‐selection rules allowing phonons with q ≠ 0 to contribute in the Raman scattering. Furthermore, three additional broad peaks are detected in the implanted samples even after implantation with the fluence of 5×1013 cm‐2. They are ascribed to disorder activated Raman scattering or acoustic overtones (300 cm‐1, 420 cm‐1) and the formation of point defects (670 cm‐1), respectively. Rapid thermal annealing at 1000 °C causes partial recovery of the lattice. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Published Version
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