PREPARATION OF [001] ORIENTED TITANIUM THIN FILM FOR MEMS APPLICATIONS BY KAUFMAN ION-BEAM SOURCE
| Authors | |
|---|---|
| Year of publication | 2018 |
| Type | Article in Proceedings |
| Conference | 9TH INTERNATIONAL CONFERENCE ON NANOMATERIALS - RESEARCH & APPLICATION (NANOCON 2017) |
| MU Faculty or unit | |
| Citation | |
| Keywords | Titanium thin film; [001] orientation; stress-free; thermal coefficient of resistivity; resistivity |
| Description | 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 approximate to 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 (rho) and the thermal coefficient of resistivity (alpha) 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 approximate to 273 degrees C. The corresponding lattice parameters a(0) and c(0) were (2.954 +/- 0.003) angstrom and (4.695 +/- 0.001) angstrom, respectively. Electrical parameters of this sample as rho and alpha were (9.2 +/- 0.1).10(-7) Omega.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 rho and high alpha are essential. We found that rho and a are dependent on each other. The rho value was approximate to 2x higher than the bulk material value, which is an excellent result for a thin film with the thickness of approximate to 80 nm. |
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