HVPE growth of Al_xGa_1-xN alloy layers

Published in:
phys. stat. sol. (c), vol. 6, no. S2, pp. S309-S312 (2009).
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Abstract:
In this work growth of Al_xGa_1-xN layers (0 < x < 0.91) by hydride vapour phase epitaxy (HVPE) is presented. The growth process is performed in a modified horizontal reactor. The measured compositions show good agreement with theoretical values calculated from a heterogeneous thermodynamic equilibrium model. The aluminum mole fractions, the homogeneity and the relaxation of the Al_xGa_1-xN layers are deduced from x-ray diffraction (XRD) measurements. Cathodoluminescence (CL) investigations of an Al_0.52Ga_0.48N sample exhibit a luminescence peak energy near the expected band edge and an additional luminescence peak between the Al_xGa_1-xN and the GaN bandgap. From XRD and spatially resolved CL measurements the peak at lower energy can be associated to crystallites with orientation different from the c-plane bulk layer that are formed on the growing surface.

PACS:
61.05.cp, 68.55.jm, 68.55.og, 78.60.Hk, 81.05.Ea, 81.15.Kk

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