scholarly journals LASER-INDUCED SURFACE ACOUSTIC WAVES FOR THIN FILM CHARACTERIZATION

2020 ◽  
Vol 27 ◽  
pp. 57-61
Author(s):  
Radim Kudělka ◽  
Lukáš Václavek ◽  
Jan Tomáštík ◽  
Sabina Malecová ◽  
Radim Čtvrtlík
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Young’S Modulus ◽  
Acoustic Waves ◽  
Young's Modulus ◽  
Surface Acoustic Waves ◽  
Laser Pulses ◽  
Data Application ◽  
Thin Film Characterization ◽  
Short Laser Pulses

Knowledge of mechanical properties of thin films is essential for most of their applications. However, their determination can be problematic for very thin films. LAW (Laser-induced acoustic waves) is a combined acousto-optic method capable of measuring films with thickness from few nanometers. It utilizes ultrasound surface waves which are excited via short laser pulses and detected by a PVDF foil. Properties such as Young’s modulus, Poisson’s ratio and density of both the film and the substrate as well as film thickness can be explored.Results from the LAW method are successfully compared with nanoindentation for Young’s modulus evaluation and with optical method for film thickness evaluation and also with literature data. Application of LAW for anisotropy mapping of materials with cubic crystallographic lattice is also demonstrated.

Young’s Modulus Detection for Ultra-Thin Film by LSAWs Technique with Wavelet and FIR Filter De-Noising

2011 ◽  
Vol 301-303 ◽  
pp. 623-628 ◽  
Author(s):  
Xing Meng Shan ◽  
Xia Xiao ◽  
Yuan Sun
Keyword(s):  
Young’S Modulus ◽  
Acoustic Waves ◽  
Young's Modulus ◽  
Surface Acoustic Waves ◽  
Low Frequency ◽  
Experimental System ◽  
Fir Filter ◽  
Least Square ◽  
Frequency Noise ◽  
Young’S Moduli

Laser-generated surface acoustic waves (LSAWs) technique is a feasible method to determine the Young’s modulus of thin films. The raw surface acoustic wave (SAW) signals detected from the experimental system are often contaminated by external noises. A novel de-noising method is proposed in this paper with wavelet and FIR filter. The wavelet threshold de-noising is essential to reduce the high frequency noise components in the raw SAW signals, while FIR filter can remove the useless low frequency noises. The useful bandwidth of the detected signal ranges from 50 to 190 MHz. Young’s modulus of the detected samples can be obtained by matching the experimental dispersive curves with the theoretical calculated ones via an improved least square fitting method. The Young’s moduli of four low dielectric constant (low-k) samples detected in the measurement are 7.1, 6.8, 1.1 and 1.0 GPa, respectively.

Young’s modulus and density of nanocrystalline cubic boron nitride films determined by dispersion of surface acoustic waves

2002 ◽  
Vol 74 (1) ◽  
pp. 41-45 ◽  
Author(s):  
G. Lehmann ◽  
P. Hess ◽  
S. Weissmantel ◽  
G. Reisse ◽  
P. Scheible ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Young’S Modulus ◽  
Acoustic Waves ◽  
Young's Modulus ◽  
Cubic Boron Nitride ◽  
Surface Acoustic Waves ◽  
Boron Nitride Films

scholarly journals Young's modulus of (Ti,Si)N films by surface acoustic waves and indentation techniques

2002 ◽  
Vol 408 (1-2) ◽  
pp. 160-168 ◽  
Author(s):  
F Vaz ◽  
S Carvalho ◽  
L Rebouta ◽  
M.Z Silva ◽  
A Paúl ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Acoustic Waves ◽  
Young's Modulus ◽  
Surface Acoustic Waves

Surface-acoustic-wave generation by thermoelasticity

1986 ◽  
Vol 320 (1554) ◽  
pp. 315-318 ◽  
Keyword(s):  
Acoustic Waves ◽  
Pulse Width ◽  
Surface Acoustic Waves ◽  
Laser Pulses ◽  
Simple Relation ◽  
Maximal Amplitude ◽  
Thermoelastic Effect ◽  
Acoustic Wave Generation ◽  
Short Laser Pulses ◽  
Temporal And Spatial

Short laser pulses were used for generating surface acoustic waves (SAWs) on aluminium via the thermoelastic effect. There exists a simple relation between the temporal and spatial pulse width at which the SAWs exhibit maximal amplitude.

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