Correlation between plasma expansion dynamics and gold-thin film structure during pulsed-laser deposition

Pulsed-laser deposition of Au thin films has been achieved by ablating a gold target with a KrF excimer Laser in various conditions of ambient Ar gas pressure (from 10−5 to 4 Torr) and target-to-substrate distance (from 1.0 to 11 cm). The dynamics of the plasma plume were measured in the same conditions. Highly oriented Au (111) thin films are obtained for pressure-distance deposition conditions such that the neutral Au species have a typical velocity larger than 2 km s−1, while a polycrystalline powder is obtained when the typical velocity is smaller than 0.8 km s−1.