Effects of laser fluence, size, and shape of the laser focal spot in pulsed laser deposition using a multielemental target

Two-dimensional distributions of thickness and of composition of the deposi t produced by the room temperature pulsed laser ablation of lead zirconate titanate in vacuum were studied experimentally as a function of laser fluen ce, of size, and of elongation of the rectangular laser focal spot. The fli p over and the elliptical shape of the deposit were observed. Increase in l aser fluence, increase in elongation, and decrease in size of the spot resu lted in a stronger broadening of the thickness profiles. The deposit was le ad deficient, with the lead profiles "inverse" to the thickness profiles. E xcess and/or nominal content of zirconium and of titanium were observed wit h the profiles resembling those of the thickness. The thickness profiles we re in general formal agreement with the model of adiabatic expansion of the monoelemental plume. An additional broadening of the profiles was ascribed to the spatial distribution of the composition in the deposit. The behavio r of the composition was qualitatively analyzed in terms of sorption of abl ated species at the substrate. Good agreement between experimental observat ions and the conclusions of the sorption analysis suggests a determining ro le of the plume-substrate interaction in the deposition process. (C) 2000 A merican Institute of Physics. [S0021-8979(00)03011-5].