Characteristics of nanostructure and electrical properties of Ti thin films as a function of substrate temperature and film thickness

• Published in: Journal of materials science Vol. 42; no. 8; pp. 2603 - 2611
• Main Authors: Savaloni, H, Khojier, K, Alaee, M. S
• Format: Journal Article
• Language: English
• Published: Heidelberg Kluwer Academic Publishers-Plenum Publishers 01-04-2007; Springer; Springer Nature B.V
• Subjects: activation energy; Anatase; Carrier density; Carriers; Coefficients; Cross-disciplinary physics: materials science; rheology; Electrical properties; Electrical resistivity; Exact sciences and technology; Film thickness; Hall effect; Halls; Materials science; Mathematical analysis; Methods of deposition of films and coatings; film growth and epitaxy; nanomaterials; Nanostructure; Other topics in materials science; Physics; Substrates; temperature; Thickness measurement; Thin films; Titanium; Titanium dioxide; X-ray diffraction; Thin films; Temperature; Nanostructures; Electrical properties; Layer thickness
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-006-1340-9

Titanium films of different thickness at different substrate temperatures are prepared using PVD method. The nanostructure of these films was obtained using X-ray diffraction (XRD) and AFM, while the thicknesses were measured by means of Rutherford back scattering (RBS) technique. Resistivity, Hall coefficient, concentration of carriers and the mobility in these films are obtained. The results show that, the rutile phase of TiO₂ is formed which is initially amorphous and as the film thickness increases it tends to become textured in (020) direction, which is more pronounced at higher temperatures and possibly transforms to anatase TiO₂ with (112) orientation for thickest films of 224 nm. The conductivity and concentration of carriers increase with thickness, while the Hall coefficient and the mobility decrease. The activation energies in these samples were obtained from the Arrhenius plots of σ and R H. For thinner films ([Formula: see text] eV) and for thickest film (224 nm) a break point is observed at about 500 K, which is consistent with the idea of more processes becoming activated at higher temperatures.