Laser fluence effect on the formation of dielectric Pb1−xLaxTi1−x/4O3 thin films

Abstract

Dielectric thin films of Pb0.72La0.28Ti0.93O3 (PLT(28)) have been deposited on Pt/Ti/SiO2/Si substrates in situ by a laser ablation at a low temperature of 450°C. We have systematically investigated the effect of the laser energy density on the properties of PLT thin films. The laser energy density has been varied from 0.4 to 3 J/cm2. The surface morphology was observed to be changed from a planar structure to a columnar structure with increasing the laser energy density by scanning electron microscopy (SEM). The crystal structure of the thin films strongly depends on the laser energy density observed by X-ray diffraction (XRD). The electrical measurement indicated that the optimized laser fluence was 2.5 J/cm2 for the fabrication of laser ablated PLT thin films which could be suitable as a dielectric capacitor film for the future DRAM applications.