KrF laser ablation target analysis and thin film deposition

Summary form only given. Mechanisms of KrF laser (248 nm, 1.2 J, 40 ns) ablation have been investigated by electron microscope analysis of targets and thin-films deposited on silicon substrates. Laser ablated (Al and Fe) targets show the formation of conical microstructures, which increase the laser absorption, but also generate larger particulate (5-15 /spl mu/m) on deposited films. The development of these microstructures has been investigated as a function of the number of incident KrF laser pulses (up to 4000). A diagnostic utilizing dye laser scattering from ablated particulate supports the evidence that KrF laser-damaged targets produce more and larger particulate than smooth targets. The time of flight from laser scattering signals gives velocities of 100 m/s for the smaller particulate and 25 m/s for the largest particulate. The effects of substrate heating on thin film deposition are being investigated. A theory of laser absorption by rough surfaces has been derived.