Epitaxial growth of GaN on {1012} oriented sapphire in GaCl/NH3/He and GaCl/NH3/H2 systems

GaN epitaxial layers were grown on {101 2} sapphire substrates in the systems GaCl/NH₃/He and GaCl/NH₃H₂, respectively. The films obtained were investigated by light microscopy, RHEED method and electron-microscopical replica technique. The epitaxial relationship was found to be {101 2} // {112 0}_GaN; 〈112 0〉 // 〈101 0〉_GaN With respect to layer perfection the temperature range of 800 … 1060°C and growth rates ≧ 1 μm/min are the best growth conditions.