from the conferences organized by TANGER Ltd. provisional website
We propose the sputtering deposition providing titanium thin films with controlled properties such as preferential crystallography and residual stress using Kaufman ion-beam source. The titanium thin films with thickness of ≈ 80 nm were deposited on [001] Si wafer covered by SiO2 deposited by plasma-enhanced chemical vapor deposition. To achieve the required crystallography and stress properties, we investigated the different beam voltage of Kaufman ion-beam source and controlled the substrate temperature during deposition using a built-in heater. We used two X-ray diffraction methods to determine the planes parallel to the sample surface and residual stress. We also measured the current-voltage curves to determine the resistivity (ρ) and the thermal coefficient of resistivity (α) of titanium thin films at different substrate temperatures using 4-probe measurement setup. We showed that it is possible to prepare stress-free titanium thin films with pure [001] orientation at the lowest beam voltage of 200 V and substrate temperature of ≈ 273 °C. The corresponding lattice parameters a0 and c0 were (2.954 ± 0.003) Å and (4.695 ± 0.001) Å, respectively. Electrical parameters of this sample as ρ and α were (9.2 ± 0.1)∙10-7 Ω∙m and (2.6 ± 0.2)∙10-3 K-1, respectively. We found out that these layers are well suitable for micro-electro-mechanical systems where the pure [001] orientation, no residual stress and low ρ and high α are essential. We found that ρ and α are dependent on each other. The ρ value was ≈ 2× higher than the bulk material value, which is an excellent result for a thin film with the thickness of ≈ 80 nm.
Keywords: titanium thin film, [001] orientation, stress-free, thermal coefficient of resistivity, resistivity© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.