Annealing studies on InN thin films grown by modified activated reactive evaporation

• Published in: Journal of crystal growth Vol. 311; no. 8; pp. 2542 - 2548
• Main Authors: Biju, Kuyyadi P., Jain, Mahaveer K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2009; Elsevier
• Subjects: A1. Annealing; A3. Modified activated reactive evaporation; B2. InN; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystalline state (including molecular motions in solids); Crystallographic aspects of phase transformations; pressure effects; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Vapor phase epitaxy; growth from vapor phase; 68.60.Dv; 78.55.Cr; B2. InN; A3. Modified activated reactive evaporation; A1. Annealing; 52.77.Dq; Oxynitrides; Temperature dependence; Electrical properties; Phase transformations; Photoluminescence; Annealing temperature; Lattice parameters; Burstein Moss effect; Indium oxide; III-V compound; Thin films; Energy gap; Vapor deposition; Optical properties; Crystal-phase transformations; Indium nitride; Thermal annealing; Carrier density; Crystal structure; 78.55.Cr A1. Annealing
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2009.01.105

We describe the effect of annealing in air and in vacuum on structural, electrical and optical properties of indium nitride (InN) thin films. The films were grown by modified activated reactive evaporation. Films annealed in air were transformed to In 2O 3 at 450 °C whereas films annealed in vacuum started decomposing at 500 °C. The c-lattice constant was found decreasing for increasing annealing temperature due to reduction of excess nitrogen in the films. The major changes in structural, electrical and optical properties appear around 400 °C. Both air and vacuum-annealed films show a reduction in the carrier concentration with annealing, explaining the observed reduction in bandgap (Moss-Burstein shift) for vacuum-annealed films. For air-annealed films, the bandgap increases when annealed, which may be due to oxynitride formation overcoming the effect of reduced carrier concentration. A decrease in the photoluminescence intensity was observed at 400 °C for air-annealed and 500 °C for vacuum-annealed films which can be attributed, respectively, to the presence of indium oxide and indium in the films. Optimal annealing temperature was observed between 400 and 450 °C in vacuum.