Optical and electrical properties of InN grown by radio-frequency reactive sputtering

• Published in: Journal of crystal growth 2002-05, Vol.241 (1), p.165-170
• Main Authors: Motlan, Goldys, E.M., Tansley, T.L.
• Format: Article
• Language: English
• Subjects: A1. Characterisation; A1. Radio-frequency; B1. Nitrides; B2. Semiconducting In compounds; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; Low-field transport and mobility; piezoresistance; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity); Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Physics
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(02)01155-7

We report on optical and electrical characterisation of InN thin films prepared by RF reactive sputtering of In target with pure nitrogen gas. The resistivity of the films is in the range of 10 −3–10 −2 Ω cm, the mobility as high as 306 cm −2 V −1 s −1 and the carrier concentration is typically in the order of 10 19 cm −3. Optical measurements show that films are highly degenerate with band gap values within 2.0–2.1 eV. Aging and annealing treatments indicate that physisorbed oxygen is eventually chemisorbed into the InN films, converting them into an oxynitride (InON) phase. This is observed through the increase of the band gap energy by about 0.2 eV in the samples aged for 6 months and an even greater increase of 0.8 eV in the samples annealed at 400°C.