Results 161 to 170 of about 409,083 (217)

Piezoelectric coefficients measured by picosecond ultrasonics

2009 IEEE International Ultrasonics Symposium, 2009
The needs for materials in thin films characterization are increasing with the raising interest for Micro-Electro-Mechanical-Systems. Picosecond ultrasonics (PU), a non-contact and non-destructive technique, has been largely developed to answer the mechanical metrology requirements of thin films technology, particularly in the field of Bulk Acoustic ...
Emery, P., Devos, Arnaud, Ben Hassine, N., Defay, E.   +3 more
openaire   +2 more sources

Picosecond ultrasonics study of metallic multilayers

Physica B: Condensed Matter, 1996
Abstract A picosecond ultrasonics study of Cu/W superlattices in periods between 5 and 20 nm has been performed. Determination of acoustic echoes, observed over 200 ps, showed a softening of the longitudinal elastic constant for the shortest periods. High frequency oscillations were also detected over the first 20 ps.
B. Perrin, B. Bonello, J.-C. Jeannet, E. Romatet   +3 more
openaire   +1 more source

Characterization of internal material properties based on laser picosecond ultrasonics

International Computing Imaging Conference
Materials such as tungsten (W), copper (Cu) for interconnects, and amorphous carbon (A-Carbon) for hard masks are critical in semiconductor manufacturing.
Yanzhong Ma, Lunan Dai, Yuanyuan Bai, Tao Sun   +3 more
semanticscholar   +1 more source

Electron diffusion in metals studied by picosecond ultrasonics

Physical Review B, 1994
We have studied the ultrasonic pulses that are generated when a picosecond light pulse is absorbed in a metallic film. The pulse shape is influenced by the distance that the hot electrons diffuse before losing their energy to the lattice. We show that this method can be used to test theories of the electron-phonon and electron-electron scattering rates.
, Tas, , Maris
openaire   +2 more sources

The development of picosecond ultrasonics

The Journal of the Acoustical Society of America, 2006
Brown University has been a center for acoustics research for a very long time. Over the past 20 years, efforts have been directed towards the development of a new measurement technique that makes possible experiments on very thin films and other small structures of current interest in the computer industry.
openaire   +1 more source

Picosecond Ultrasonics: The prefered tool for BAW characterization

2008 IEEE Ultrasonics Symposium, 2008
Since the 80's, RF-filtering has carried the developments of Bulk Acoustic Wave (BAW) resonators. At the same time, picosecond ultrasonics, a non-contact and non-destructive technique for mechanical characterization, sees the light of day as an on-product process control measurements technique.
Emery, P., Devos, Arnaud, Ancey, P.
openaire   +2 more sources

Picosecond ultrasonics in a single biological cell

2008 IEEE Ultrasonics Symposium, 2008
Picosecond ultrasonics is a non-destructive method for measuring mechanical and thermal properties such as sound velocity or heat conductivity at sub-micron scale. This technique uses femtosecond laser pulses for generating and detecting GHz acoustics waves.
M. Ducousso, C. Rossignol, B. Audoin, F. Guillemot, M.C. Durrieu   +4 more
openaire   +2 more sources

Phonons rectification in picosecond laser ultrasonics

The Journal of the Acoustical Society of America, 2008
In standard ultrafast acoustic experiments very short coherent acoustic pulses are generated by the absorption of a femtosecond laser pulse in a thin metallic transducer deposited on the sample. Subsequently the acoustic pulses and the heat generated in the transducer cross the sample and are partially transmitted in the underlaying substrate.
Bernard Perrin, Shuo Zhang, Laurent Belliard, Emmanuel Péronne   +3 more
openaire   +1 more source

Imaging Nanostructures with Picosecond Ultrasonic Pulses

2005
We describe a novel imaging technique that employs coherent acoustic phonon pulses which are generated and detected by ultrafast optical methods. Sub-micron resolution images of Al patterns lithographically etched on a Si substrate are shown.
Brian C. Daly, Niels C.R. Holme, Takashi Buma, Cyril Branciard, Theodore B. Norris, S. Pau, D.M. Tennant, J.A. Taylor, J.E. Bower   +8 more
openaire   +1 more source

Non-Destructive Testing Using Picosecond Ultrasonics

AIP Conference Proceedings, 2006
Picosecond ultrasonics has become a widely used metrology tool in the semiconductor device industry. It provides an accurate method for the measurement of the thickness of thin films, can determine the quality of the bonding between a film and a substrate, and gives information about mechanical properties. We describe the development of this technology
openaire   +1 more source