Pulsed Laser Deposition of Thin Metallic Multilayers and Amorphous Films

Abstract

ABSTRACTThe method of pulsed excimer laser ablation using KrF radiation was applied for the deposition of thin metallic elementary multilayers. Above an ablation threshold of about 5 J/cm2 an ‘explosive’ evaporation of the metallic targets occurs leading to high deposition rates of up to 5 nm/s. For different metals, the ablation threshold slightly varies leading at the same laser fluence to different growth rates as shown for Ag, Fe, Zr and Nb. By using two elementary targets and adjusting the dwelling times on both targets, Fe/Ag, Fe/Zr and Fe/Nb multilayers of different bilayer thicknesses were deposited. While Fe/Ag superstructures show crystalline phases down to a periodicity of 1 nm, Fe/Zr and Fe/Nb films are amorphous at such wavelengths. On the other side, Fe/Nb multilayers can also be amorphized by a solid state interdiffusion reaction of the elementary multilayers. The surfaces of the grown films are smooth except for a small number of droplets on the film surface.