Decreasing Density of Grown-in Dislocations in AlN/c-Sapphire Templates Grown by Plasma-Activated Molecular Beam Epitaxy

Abstract

AlN/c-sapphire templates grown by plasma-activated molecular beam epitaxy have been studied using multicrystal X-ray diffractometry and a multi-beam optical stress meter system. Studies of the seed and buffer layers grown at different ratios of Al and N* growth flows and substrate temperatures have shown that templates with small tensile elastic stresses (<0.5 GPa) and densities of screw and edge grown-in dislocations 4 × 108 and 8 × 109 cm−2, respectively, can be produced.