Depth profiling of GaN by cathodoluminescence microanalysis

We present the results of a depth-resolved cathodoluminescence (CL) and tra nsmission electron microscopy study of autodoped GaN grown on sapphire. Dep th-resolved CL analysis can be used for depth profiling of the yellow lumin escence (YL) center concentration which was found to increase with depth. T he results are consistent with the (O-N - V-Ga)(2-) complex model of YL cen ters [J. Neugebauer and C. G. Van de Walle, Appl. Phys. Lett. 69, 503 (1996 ) and T. Mattila and R. M. Nieminen, Phys. Rev. B 55, 9571 (1996)]. Depth p rofiling of the near-edge emission in GaN layers thicker than similar to 0. 5 mu m is not possible due to strong self-absorption. (C) 1999 American Ins titute of Physics. [S0003-6951(99)04108- X].