The Effect of Annealing on the Structural and Optical Properties of Titanium Dioxide Films Deposited by Electron Beam Assisted PVD

• Published in: Advances in materials science and engineering 2013-01, Vol.2013 (2013), p.1-10
• Main Authors: Abdulraheem, Yaser M., Ghoraishi, Sahar, Arockia-Thai, Lidia, Zachariah, Suji K., Ghannam, Moustafa
• Format: Article
• Language: English
• Subjects: Colleges & universities; Grain growth; Nitrogen; Scanning electron microscopy; Semiconductor research; Titanium
• ISSN: 1687-8434; 1687-8442
• DOI: 10.1155/2013/574738

Titanium dioxide thin films were deposited on crystalline silicon substrates by electron beam physical vapor deposition. The deposition was performed under vacuum ranging from 10−5 to 10−6 Torr without process gases, resulting in homogeneous TiO2-x layers with a thickness of around 100 nm. Samples were then annealed at high temperatures ranging from 500°C to 800°C for 4 hours under nitrogen, and their structural and optical properties along with their chemical structure were characterized before and after annealing. The chemical and structural characterization revealed a substoichiometric TiO2-x film with oxygen vacancies, voids, and an interface oxide layer. It was found from X-ray diffraction that the deposited films were amorphous and crystallization to anatase phase occurred for annealed samples and was more pronounced for annealing temperatures above 700°C. The refractive index obtained through spectroscopic ellipsometry ranged between 2.09 and 2.37 in the wavelength range, 900 nm to 400 nm for the as-deposited sample, and jumped to the range between 2.23 and 2.65 for samples annealed at 800°C. The minimum surface reflectance changed from around 0.6% for the as-deposited samples to 2.5% for the samples annealed at 800°C.