Publications

Effect of threading dislocations on the Bragg peakwidths of GaN, AIGaN, and AIN heterolayers

Allerman, A.A.; West, Allen W.; Waldrip, Karen E.; Follstaedt, D.M.; Provencio, P.N.; Koleske, Daniel K.

We develop a reciprocal-space model that describes the (hkl) dependence of the broadened Bragg peakwidths produced by x-ray diffraction from a dislocated epilayer. We compare the model to experiments and find that it accurately describes the peakwidths of 16 different Bragg reflections in the [010] zone of both GaN and AlN heterolayers. Using lattice-distortion parameters determined by fitting the model to selected reflections, we estimate threading-dislocation densities for seven different GaN and AlGaN samples and find improved agreement with transmission electron microscopy measurements.