Investigation of TiO2-doped HfO2 thin films deposited by photo-CVD
| Autor: | J.X. Wu, Carmen Jiménez, Hywel O. Davies, Barry O'Sullivan, Ian W. Boyd, J.-Y. Zhang, Zhongping Wang, Q. Fang, M.A. Audier, T.L. Leedham, J.P. Sénateur, Paul K. Hurley |
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| Rok vydání: | 2003 |
| Předmět: |
Anatase
Materials science Metals and Alloys Analytical chemistry chemistry.chemical_element Mineralogy Surfaces and Interfaces Chemical vapor deposition Surfaces Coatings and Films Electronic Optical and Magnetic Materials Amorphous solid Surface coating chemistry.chemical_compound chemistry X-ray photoelectron spectroscopy Materials Chemistry Titanium isopropoxide Thin film Titanium |
| Zdroj: | Thin Solid Films. 428:263-268 |
| ISSN: | 0040-6090 |
| DOI: | 10.1016/s0040-6090(02)01221-x |
| Popis: | TiO 2 -doped HfO 2 thin films, as potential replacements for SiO 2 as high- k gate dielectric material, have been grown by photo-induced CVD using 222 nm excimer lamps at a temperature of 400 °C. Vaporised titanium isopropoxide and hafnium (IV) tetra- t -butoxide were used as the precursors. Films from approximately 45–70 nm in thickness with refractive indices from 1.850 to 2.424 were grown with various Ti:Hf ratios. The as-deposited films were found to be amorphous by X-ray diffraction when the Ti/(Ti+Hf) value was up to 33%, while the crystalline TiO 2 anatase phase formed when the Ti/(Ti+Hf) was 41%. We also found that the refractive index increased sharply when the Ti/(Ti+Hf) was over 25%. Fourier transform infrared spectroscopy, XPS and TEM were also used to monitor as well as the presence of Ti, interface and microstructure of the films on Si-substrate. The effect of UV-annealing on the electrical properties of these films will also be discussed. |
| Databáze: | OpenAIRE |
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