1.5 MeV proton irradiation effects on electrical and structural properties of TiO2/n-Si interface

• Published in: Journal of applied physics 2014-05, Vol.115 (17)
• Main Authors: Ishfaq, M., Rizwan Khan, M., Bhopal, M. F., Nasim, F., Ali, A., Bhatti, A. S., Ahmed, I., Bhardwaj, Sunil, Cepek, Cinzia
• Format: Article
• Language: English
• Subjects: Anatase; Applied physics; Dependence; Electrical properties; Interface stability; Proton beams; Proton irradiation; Radiation dosage; Silicon substrates; Thin films; Titanium dioxide; X ray photoelectron spectroscopy; X ray spectra; X-ray diffraction
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4874942

In this paper, we report the effect of 1.5 MeV proton beam irradiation dose on the structural and electrical properties of TiO2 thin films deposited on n–Si substrates. The formation and transformation of different TiO2 phases in the irradiated thin films were characterized by X-ray diffraction and X-ray photoelectron spectroscopy (XPS). X-ray diffraction measurements revealed that the as grown film was rich in Ti5O9 phase and then converted to mixed phases of TiO2 (rutile and anatase) after exposure with radiation doses up to 5 × 1014 cm−2. The XPS results revealed the formation of oxygen vacancy (negative) traps in the exposed TiO2 films, which showed strong dependence on the dose. The C-V measurements showed that proton radiations also damaged the Si substrate and created deep level defects in the substrate, which caused a shift of 0.26 ± 0.01 V in the flat band voltage (VFB). I–V measurements showed that the ideality factor increased and the rectification ratio dropped with the increase in the radiation dose. The present study showed the stability of TiO2/Si interface and TiO2 film as an oxide layer against proton radiations.