Gallium nitride thin layers via a liquid precursor route

• Published in: Journal of crystal growth 2000, Vol.208 (1), p.153-159
• Main Authors: Puchinger, Manfred, Wagner, Thomas, Rodewald, Dieter, Bill, Joachim, Aldinger, Fritz, Lange, Frederick F.
• Format: Article
• Language: English
• Subjects: Chemical solution deposition; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Gallium nitride (GaN); Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids); Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Precursor pyrolysis; Sapphire (Al 2O 3); Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Thin films; Transmission electron microscopy (TEM)
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(99)00416-9

A chemical solution deposition method was used to grow thin epitaxial GaN films on C- and R-plane sapphire substrates. The films were grown by spin-coating a gallium carbodiimide based polymeric precursor onto sapphire and pyrolyzing in NH 3 at 900°C. During heat treatment α-GaN formed on the R-plane of the sapphire with the following epitaxial orientation relationship: α-Al 2O 3(0 1 1 ̄ 2)‖α-GaN(1 1 2 ̄ 0); α-Al 2O 3[2 1 ̄ 1 ̄ 0]‖α-GaN[1 1 ̄ 0 0]. A multiple coating process resulted in films fully covering the R-plane substrates. Films deposited on C-plane sapphire were not continuous and single islands were present on the substrate surface. The morphology and microstructure of the films were characterised by SEM, XRD, and conventional and analytical electron microscopy.