Jeudi 12 janvier 2006
Recent developments in laser ultrasonics make it possible to study the propagation of sound in samples of thickness as small as a few nm. In these experiments, femtosecond light pulses are used to generate and detect the sound. The light pulse is absorbed in a region of the sample and the relaxation of this stress launches a strain pulse into the sample. When acoustic echoes return to the sample surface they are detected by means of a time-delayed probe light pulse.
The technique has found broad application in the semiconductor industry, where it is used to characterize the metal films serving as interconnects between transistors in computer chips. The talk will describe the evolution of the technology and the technology transfer process.