Abstract
This study investigates the reduction in nanomechanical properties of a tungsten (W) thin film measured using a laser ultrasonic technique. A 96 nm thick W film was prepared via direct-current magnetron sputtering and inspected using scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffraction, and X-ray reflectivity techniques. Moreover, frequency-domain photoacoustic microscopy was employed to evaluate the Young's modulus (EW) of W. The velocity dispersion of a surface acoustic wave excited by an intensity-modulated laser was measured and curve-fitted using a computational finite element model to estimate EW. In addition, a high-frequency microcantilever resonance test was performed to verify the results. The results show that EW of the film is 45.3% lower than that of the macroscopic property because of the predominant β-W phase. The Young's moduli obtained from the two different techniques agree well with each other, with a relative error of 13.3%. The hardness-to-EW ratio obtained using a nanoindenter was calculated to be 0.025±0.004.
Original language | English (US) |
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Article number | 139050 |
Journal | Thin Solid Films |
Volume | 742 |
DOIs | |
State | Published - Jan 31 2022 |
Funding
This work was supported by the research fund of Chungnam National University. The W sample was prepared in the UNIST Central Research Facilities. The SEM-EDX analysis was conducted in the Electro Ceramics Center, Dong-eui University. The GIXRD and XRR analyses were carried out in the Center for Research Facilities, Chungnam National University and the Korea Base Science Institute, respectively. The nanoindentation testing was performed in the National NanoFab Center, Korea Advanced Institute of Science and Technology. The frequency-domain photoacoustic microscopy was conducted in the Center for Smart Structures and Materials, Northwestern University.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry