| AVS 63rd International Symposium & Exhibition | |
| Thin Film | Thursday Sessions |
| Session TF-ThP |
| Session: | Thin Films Poster Session |
| Presenter: | Victor Lima, State University of Campinas, Brazil |
| Authors: | V. Lima, State University of Campinas, Brazil I. Doi, State University of Campinas, Brazil J.A. Diniz, State University of Campinas, Brazil R.R. César, State University of Campinas, Brazil |
| Correspondent: | Click to Email |
This work presents the results of the physical characterization of TiOx thin films obtained under different deposition conditions such as O2/Ar ratio and deposition plasma power using dc reactive sputtering process. Two sets of the films were prepared, one set varying the sputtering discharge power ranging from 600 W to 1500 W, at constant gas flow ratio of Ar = 60 sccm and O2 = 40 sccm, and 10 minutes deposition time. Other set of the TiOx films were prepared with constant 1000 W deposition power for 10 minutes and gas flow O2/Ar ratio ranging from 0.166 to 0.5. The obtained samples of both sets were all characterized by different techniques, ellipsometry, Raman spectroscopy, Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) to determine thickness and refractive index of the films, crystalline structure, roughness and surface morphology, respectively. The ellipsometry results show that deposition rate of the samples increases linearly as the power increases, and that the refractive index slightly decreases with the power increment, remaining however between 2.44 and 2.47, therefore close to the typical value of titanium oxide. As for the crystalline structure, the results of the Raman spectroscopy showed Raman shift peaks at 150, 230, 420, 600, 670 and 810 cm-1, corresponding to anatase and rutile form of TiOx thin films, which agree to those results observed by different researchers. The obtained spectra demonstrate also that the brookite structure was not found on the studied TiOx samples. AFM images showed rms roughness ranging from 0.150 nm for the samples obtained at 600 W deposition power to 0.872 nm for those obtained at 1500 W deposition power, that may explained considering increase of temperature at the sample surface and sputtered materials from the target. The c haracterization of the second set of the TiO x samples, showed that deposition rates increases as more Ar is provided to the sputtering atmosphere, as well as the refractive index, this one exhibiting a small increment as O2 ratio is increased, with low standard deviation values, showing deposition of the films with quite homogeneous surface. AFM and Raman results showed very small variations in rms roughness of the samples and crystalline structure when gas flow ratio were varied, remaining around the values of 0.441 nm roughness and Raman peaks of anatase and rutile crystalline structure, similar results as those observed for the first set of the samples. These exhibited properties of TiOx obtained by dc reactive magnetron sputtering technique, make it a interesting material for several applications, for instances for dielectric in semiconducting FETs.