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 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry