Low temperature growth of gallium nitride

Radio frequency reactive sputtering was used to produce gallium nitride fil ms on glass and silicon substrates at close to room temperature. The films were analysed by transmission electron microscopy and Rutherford backscatte ring spectroscopy. The films were found to consist of nanocrystalline wurtz ite GaN with c-axis-oriented columnar grains growing perpendicular to the s ubstrate. Varying the N-2:Ar sputtering gas ratio was found to have little effect on the grain size. Annealing the films at 400 degrees C was found to increase the E-1(TO) signal observed by Fourier transform LR spectroscopy and to reduce the porosity of the columnar structure. (C) 2000 Elsevier Sci ence S.A. All rights reserved.