Member of technical staff, David Sarnoff Research Center, RCA Laboratories, Princeton, N.J.
Pages: 12 Published: Jan 1978
Laser spallation is a technique for detaching thin films from substrates by impinging a pulsed, high-energy laser beam onto the back side of a substrate (made opaque in the case of transparent substrates). The explosive evaporation of absorbing material on the back side sends a recoil compressive shock wave through the substrate toward the film-substrate interface. The substrate then snaps back in tension. Threshold values for film detachment can yield information about the film-substrate bonds without contact with or disturbance of the film surface. Thus damage propagated to the interface from film surface disturbance is eliminated. In some cases it is possible to examine [for example, by Auger electron spectroscopy (AES)] the spalled dot and the region of the substrate from which it was spalled to determine the locus of failure and to obtain information about interface formation.
adhesion, interfaces, thin films, laser shock waves, laser damage
Paper ID: STP38629S