ANALYTICAL DESCRIPTION OF THE FILM THICKNESS DISTRIBUTION OBTAINED BYTHE PULSED-LASER ABLATION OF A MONOATOMIC TARGET - APPLICATION TO SILICON AND GERMANIUM

In this work, the spatial distribution of laser-generated species in v acuum from a monoatomic target is deduced from the analytical resoluti on of the hydrodynamic equations for a plasma expanding in the adiabat ic regime. The thickness distribution of the laser deposited layers is demonstrated to be related to the initial dimensions of the plasma bu t independent of both the laser fluence and the atomic mass of the tar get element. From these calculations, we also deduced an angular distr ibution of the deposits as a sum of cos(n) theta. These theoretical re sults are experimentally supported in the specific case of the pulsed excimer laser ablation of Si and Ge monoatomic targets.