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Journal of Nanomaterials
Volume 2013 (2013), Article ID 154179, 7 pages
http://dx.doi.org/10.1155/2013/154179
Research Article

Nanoindentation and Adhesion Properties of Ta Thin Films

Department of Materials Science and Engineering, I-Shou University, Kaohsiung 840, Taiwan

Received 1 February 2013; Revised 6 March 2013; Accepted 14 March 2013

Academic Editor: Ugur Serincan

Copyright © 2013 Yuan-Tsung Chen. 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.

Abstract

Ta films were sputtered onto a glass substrate with thicknesses from 500 Å to 1500 Å under the following conditions: (a) as-deposited films were maintained at room temperature (RT), (b) films were postannealed at °C for 1 h, and (c) films were postannealed at °C for 1 h. X-ray diffraction (XRD) results revealed that the Ta films had a body-centered cubic (BCC) structure. Postannealing conditions and thicker Ta films exhibited a stronger Ta (110) crystallization than as-deposited and thinner films. The nanoindention results revealed that Ta thin films are sensitive to mean grain size, including a valuable hardness ( ) and Young’s modulus ( ). High nanomechanical properties of as-deposited and thinner films can be investigated by grain refinement, which is consistent with the Hall-Petch effect. The surface energy of as-deposited Ta films was higher than that in postannealing treatments. The adhesion of as-deposited Ta films was stronger than postannealing treatments because of crystalline degree effect. The maximal and and the optimal adhesion of an as-deposited 500-Å-thick Ta film were 15.6 GPa, 180 GPa, and 51.56 mJ/mm2, respectively, suggesting that a 500-Å-thick Ta thin film can be used in seed and protective layer applications.