Polarity determination by atomic location by channeling-enhanced microanalysis

In this letter, an alternative approach to determine the polarity of GaN thin films based on the atomic location by channeling-enhanced microanalysis technique is described. Theoretical calculations provide a straightforward criterion for polarity determination that is a major advantage of this method. At the Bragg position, the thickness-averaged incident electron intensity, and hence, electron induced characteristic x-ray yield, is higher on the N plane than on the Ga if the g vector of the diffraction beam is parallel to the Ga-N bond direction, and vice versa. Experimental results support the theoretical predictions. The possible errors in the experiments are also discussed. (C) 2002 American Institute of Physics.