Detailed studies of aluminum thin films morphology deposited by pulsed laser ablation

Abstract: In the present paper we report the investigations by scanning electron microscopy of Al thin films prepared by pulsed laser ablation deposition experiments in vacuum. Laser parametric studies show that the poor thickness uniformity of Al films arises from surface roughening and structure formation on the irradiated Al target surface. Moreover, it has been confirmed that the plume deflection effect, the morphological changes of the irradiated target surfaces and of the deposited films strongly depend on the laser fluence (4.6–14.7J/cm2). At low laser fluence, plume deflection angles up to 12° and columnar structures on the target surface have been observed. The variation in the target morphology and in the droplets density of the deposited films can be associated with competitive ablation processes related to different values of local incident laser fluence. Systematic profilometric investigations of the deposited Al films revealed a strong asymmetry during the deposition process. These results confirm once again our previous achievements obtained with Si laser ablation experiments. [ABSTRACT FROM AUTHOR]