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2009
Conference Paper
Titel
Reduction of the threading edge disclocation density in AlGaN epilayers by GaN nucleation
Abstract
Al0.15Ga0.85N films were grown on sapphire (0001) by metalorganic vapor phase epitaxy using thin low-temperature GaN nucleation layers. After etching in flowing hydrogen and ammonia, these nucleation layers exhibit a three-dimensional facetted structure. A systematical variation of the growth temperature and V/III-ratio of the subsequent AlGaN layers was carried out in order to optimize the overgrowth resulting in smooth surfaces as revealed by atomic force microscopy. An effective reduction of the threading edge dislocation density in the overgrowing AlGaN layers is proven by high-resolution X-ray diffraction.
Author(s)