Characteristics of the heteroepitaxy of gallium and aluminum nitrides

Epitaxial layers of GaN and AlN on sapphire substrates have been grown by various techniques from organometallic compounds M(CH3)3 and NH3 (where M is Ga or Al) and by pyrolysis of ammonium-chloride complexes of Ga and Al. It is shown that the structure and surface morphology of the epitaxial layers can be substantially improved by using high growth rates (1-1.5 micron/min) at the initial growth stage.