High Frequency Ultrasound, a Tool for Elastic Properties Measurement of Thin Films Fabricated on Silicon

2011 ◽  
Vol 324 ◽  
pp. 277-281 ◽  
Author(s):  
Pierre Campistron ◽  
Julien Carlier ◽  
Nadine Saad ◽  
Jamin Gao ◽  
Malika Toubal ◽  
...  
Keyword(s):  
Thin Films ◽  
Elastic Properties ◽  
High Frequency ◽  
Shear Waves ◽  
Thin Layers ◽  
Acoustic Properties ◽  
Frequency Range ◽  
Frequency Method ◽  
Longitudinal Waves

The main goal of this work is to develop an ultrasonic high frequency method for characterization of thin layers. The development of high frequency acoustic transducers for longitudinal waves and shear waves on silicon has enabeled the characterization of thin films deposited on this substrate. Three types of transducers have been achieved : (i) single crystal LiNbOSubscript text3 Y+163° for shear waves generation, and (ii) Y+36° for longitudinal waves, bonded and thinned on silicon substrate to achieve ultrasonic transducers in the frequency range 300-600 MHz ; (iii) thin films ZnO transducers were realized due to sputtering technologies working in the frequency range 1 GHz- 2.5 GHz. Using an inversion method and a network analyser which provide the scattering S11 parameter of the transducer versus the frequency we deduce the elastic properties of films deposited on the wafer surface. Thanks to these transducers the acoustic properties of thin films such as SU-8 based nanocomposites (doped with TiO2 , SrTiO3 or W nanoparticles) will be presented. In order to achieve mechanical impedance matching between silicon and water we control the mass of the embedded particles which provide a way to adjust the elastic properties of the characterized material. In another application an Indium metallic layer have been characterized in the high frequency range. We also use this method to characterize dielectric permittivity of the ZnO transducers.

Thermorheological Characterization of Elastoviscoplastic Carbopol Ultrez 20 Gel

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
M. A. Hassan ◽  
Manabendra Pathak ◽  
Mohd. Kaleem Khan
Keyword(s):  
Experimental Investigation ◽  
Yield Stress ◽  
Elastic Properties ◽  
Viscous Dissipation ◽  
Power Law ◽  
Effect Of Temperature ◽  
Rheological Parameters ◽  
Frequency Range ◽  
Power Law Index

The temperature and concentration play an important role on rheological parameters of the gel. In this work, an experimental investigation of thermorheological properties of aqueous gel Carbopol Ultrez 20 for various concentrations and temperatures has been presented. Both controlled stress ramps and controlled stress oscillatory sweeps were performed for obtaining the rheological data to find out the effect of temperature and concentration. The hysteresis or thixotropic seemed to have negligible effect. Yield stress, consistency factor, and power law index were found to vary with temperature as well as concentration. With gel concentration, the elastic effect was found to increase whereas viscous dissipation effect was found to decrease. Further, the change in elastic properties was insignificant with temperature in higher frequency range of oscillatory stress sweeps.

Shallow subsurface mapping by electromagnetic sounding in the 300 kHz to 30 MHz range: Model studies and prototype system assessment

Geophysics ◽  
1994 ◽  
Vol 59 (8) ◽  
pp. 1201-1210 ◽  
Author(s):  
Duff C. Stewart ◽  
Walter L. Anderson ◽  
Thomas P. Grover ◽  
Victor F. Labson
Keyword(s):  
Dielectric Permittivity ◽  
High Frequency ◽  
Low Frequency ◽  
Computer Programs ◽  
Thin Layers ◽  
Depth Range ◽  
Frequency Range ◽  
Model Studies ◽  
New Instrument ◽  
Displacement Currents

A new instrument designed for frequency‐domain sounding in the depth range 0–10 m uses short coil spacings of 5 m or less and a frequency range of 300 kHz to 30 MHz. In this frequency range, both conduction currents (controlled by electrical conductivity) and displacement currents (controlled by dielectric permittivity) are important. Several surface electromagnetic survey systems commonly used (generally with frequencies less than 60 kHz) are unsuitable for detailed investigation of the upper 5 m of the earth or, as with ground‐penetrating radar, are most effective in relatively resistive environments. Most computer programs written for interpretation of data acquired with the low‐frequency systems neglect displacement currents, and are thus unsuited for accurate high‐frequency modeling and interpretation. New forward and inverse computer programs are described that include displacement currents in layered‐earth models. The computer programs and this new instrument are used to evaluate the effectiveness of shallow high‐frequency soundings based on measurement of the tilt angle and the ellipticity of magnetic fields. Forward model studies indicate that the influence of dielectric permittivity provides the ability to resolve thin layers, especially if the instrument frequency range can be extended to 50 MHz. Field tests of the instrument and the inversion program demonstrate the potential for detailed shallow mapping wherein both the resistivity and the dielectric permittivity of layers are determined. Although data collection and inversion are much slower than for low‐frequency methods, additional information is obtained inasmuch as there usually is a permittivity contrast as well as a resistivity contrast at boundaries between different materials. Determination of dielectric permittivity is particularly important for hazardous waste site characterization because the presence of some contaminants may have little effect on observed resistivity but a large effect on observed permittivity.

Characterization of collagen by high-frequency ultrasound: Evidence for different acoustic properties based on collagen fiber morphologic characteristics

1997 ◽  
Vol 133 (3) ◽  
pp. 364-368 ◽  
Author(s):  
P.Anthony N. Chandraratna ◽  
Peter Whittaker ◽  
Previn M. Chandraratna ◽  
Jacqueline Gallet ◽  
Robert A. Kloner ◽  
...  
Keyword(s):  
High Frequency ◽  
Collagen Fiber ◽  
Acoustic Properties ◽  
High Frequency Ultrasound ◽  
Morphologic Characteristics ◽  
Ultrasound Evidence ◽  
Frequency Ultrasound

scholarly journals Time-Domain Investigations of Coherent Phonons in van der Waals Thin Films

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2543
Author(s):  
Fabien Vialla ◽  
Natalia Del Fatti
Keyword(s):  
Thin Films ◽  
Time Domain ◽  
Van Der Waals ◽  
Optical Excitation ◽  
Thin Layers ◽  
Interface Defect ◽  
Optical And Electronic Properties ◽  
Coherent Phonons ◽  
Structural Configurations

Coherent phonons can be launched in materials upon localized pulsed optical excitation, and be subsequently followed in time-domain, with a sub-picosecond resolution, using a time-delayed pulsed probe. This technique yields characterization of mechanical, optical, and electronic properties at the nanoscale, and is taken advantage of for investigations in material science, physics, chemistry, and biology. Here we review the use of this experimental method applied to the emerging field of homo- and heterostructures of van der Waals materials. Their unique structure corresponding to non-covalently stacked atomically thin layers allows for the study of original structural configurations, down to one-atom-thin films free of interface defect. The generation and relaxation of coherent optical phonons, as well as propagative and resonant breathing acoustic phonons, are comprehensively discussed. This approach opens new avenues for the in situ characterization of these novel materials, the observation and modulation of exotic phenomena, and advances in the field of acoustics microscopy.

Ferroelectric Thin Films for Applications in High Frequency Range

2005 ◽  
Vol 316 (1) ◽  
pp. 7-12 ◽  
Author(s):  
A. Rousseau ◽  
M. Guilloux-Viry ◽  
V. Bouquet ◽  
A. Perrin ◽  
G. Tanné ◽  
...  
Keyword(s):  
Thin Films ◽  
High Frequency ◽  
Ferroelectric Thin Films ◽  
High Frequency Range ◽  
Frequency Range

scholarly journals Growth of Diamond Thin Films and Characterization of Acoustic Properties. (2).

Shinku ◽  
1997 ◽  
Vol 40 (3) ◽  
pp. 216-219
Author(s):  
Kazuhiko KOBAYASHI ◽  
Kunihito IWASHITA ◽  
Masatoshi NOGUCHI ◽  
Takuro KOIKE
Keyword(s):  
Thin Films ◽  
Acoustic Properties ◽  
Diamond Thin Films

Characterization of elastic properties of SiO2 thin films by ultrasonic microscopy

2014 ◽  
Author(s):  
Tatsuya Omori ◽  
Kensuke Sakamoto ◽  
Satoshi Suzuki ◽  
Jun-ichi Kushibiki ◽  
Satoru Matsuda ◽  
...  
Keyword(s):  
Thin Films ◽  
Elastic Properties

RF Magnetron Sputtered Ba0.96Ca0.04Ti0.84Zr0.16O3 Thin Films for High Frequency Applications

2004 ◽  
Vol 833 ◽  
Author(s):  
Ali Mahmud ◽  
T. S. Kalkur ◽  
N. Cramer
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Dielectric Constant ◽  
Substrate Temperature ◽  
High Frequency ◽  
Satellite Communications ◽  
Ferroelectric Thin Films ◽  
Paraelectric State ◽  
Deposited Films

ABSTRACTPerovskite ferroelectric thin films in the paraelectric state exhibit outstanding dielectric properties, even at high frequencies (>1 GHz). The tunable dielectric constant of ferroelectric thin films can be used to design frequency and phase agile components. High dielectric constant thin film ferroelectric materials in the paraelectric state have received enormous attention due to their feasibility in applications such as decoupling capacitors and tunable microwave capacitors; the latter application has been fueled by the recent explosion in wireless and satellite communications. This paper reportsBa0.96Ca 0.04Ti0.84Zr0.16O3 (BCTZ) thin films that were deposited on Pt electrodes using radio frequency magnetron sputtering at a low (450 °C) substrate temperature. Sputtered thin film BCTZ at low substrate temperature is compatible with conventional integrated circuit technology. The structural characterization of the deposited films was performed by x-ray diffraction. The electrical characterization of the films was achieved by capacitance-voltage, current-voltage, and S-parameter (via vector network analyzer) measurements. In addition, the effect of post annealing on the deposited films was investigated. A detailed understanding of both their processing and material properties is discussed for successful implementation in high frequency applications.

Electrical characterization of nickel manganite powders in high-frequency range

2013 ◽  
Vol 554 ◽  
pp. 264-270 ◽  
Author(s):  
Goran M. Stojanović ◽  
Goran Kitić ◽  
Slavica M. Savić ◽  
Vesna Crnojević-Bengin
Keyword(s):  
High Frequency ◽  
Electrical Characterization ◽  
High Frequency Range ◽  
Frequency Range

Photo-Acoustic Measurement of Thermal Conductivity of Thin Films and Bulk Materials

2000 ◽  
Vol 123 (1) ◽  
pp. 138-144 ◽  
Author(s):  
Xinwei Wang ◽  
Hanping Hu ◽  
Xianfan Xu
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
High Frequency ◽  
Conductivity Measurement ◽  
Frequency Range ◽  
Bulk Materials ◽  
Fitting Method ◽  
Thin Nickel ◽  
Conductivity Of Thin Films ◽  
Si Wafer

The photoacoustic (PA) technique is one of many techniques for measuring thermal conductivity of thin films. Compared with other techniques for thermal conductivity measurement, the photoacoustic method is relatively simple, yet is able to provide accurate thermal conductivity data for many types of thin films and bulk materials. In this work, the PA measurement in a high frequency range is made possible by a newly developed PA apparatus, which extends the limit of the PA technique. Thermal conductivities of SiO2 with thicknesses from 0.05 to 0.5 μm on Si wafer, e-beam evaporated thin nickel film on Si wafer, and thermal barrier coatings are obtained. In addition to the commonly used phase shift fitting, which is only appropriate for thermally-thin films, an amplitude fitting method is developed and employed for measuring both thin films and bulk materials with smooth or rough surfaces. Comparing results by amplitude fitting to those obtained by other methods and reference values shows good agreements. Applications and limitations of the photoacoustic technique are discussed.

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