| AVS 54th International Symposium | |
| Thin Film | Thursday Sessions |
| Session TF-ThP |
| Session: | Aspects of Thin Films Poster Session |
| Presenter: | A.P. Warren, University of Central Florida |
| Authors: | A.P. Warren, University of Central Florida R.M. Todi, University of Central Florida B. Yao, University of Central Florida K.B. Sundaram, University of Central Florida K. Barmak, Carnegie Mellon University K.R. Coffey, University of Central Florida |
| Correspondent: | Click to Email |
Microstructure and the electronic work function of Pt-Ru alloy thin films spanning the compositional range from pure Pt to pure Ru were investigated. Nominally 50 nm thick films were co-sputtered from elemental targets in an ultra high vacuum chamber. X-ray reflectivity and Rutherford backscattering spectroscopy were used to determine the film thicknesses and compositions. The electronic work function of the alloy film samples was determined by analysis of the capacitance-voltage characteristics of films deposited as part of a metal-oxide-semiconductor capacitor structure and found to range from 4.8 eV for pure Ru to 5.2 eV for pure Pt. To better understand the variation in work function for the intermediate compositions, a variety of characterization techniques were used. Transmission electron microscopy was used to examine the microstructure of the samples, and to assess the grain size variation. X-ray and electron diffraction were used to identify the crystalline phases present and to evaluate the extent of crystallographic texture. A notable increase in the compositional range of the hexagonal close packed (hcp) phase was observed, suggesting a metastable extension of the hcp phase stability as compared to bulk Pt-Ru alloys. The steepest change in the electronic work function for the intermediate alloy compositions coincided with a rapid change in the c/a ratio of the hcp phase.