Molecular beam epitaxy of gallium nitride by electron cyclotron resonance plasma and hydrogen azide

Abstract

GaN films were grown on (0001) sapphire by molecular beam epitaxy (MBE). Two sources of activated nitrogen were investigated: an electron cyclotron resonance (ECR) plasma, and hydrogen azide (HN 3). With the ECR plasma source, typical growth rates were ∼ 0.1 μm/h. Films grown in this manner showed significant surface damage from ions, and little if any photoluminescence. With HN 3, growth rates were ∼ 0.25 μm/h. Azide-grown films showed smooth surfaces, and sharp band-to-band photoluminescence. This is the first reported use of HN 3 to grow III–V nitrides by MBE, and it shows great promise as a nitrogen source.