Surface roughness of PbZrxTi1-xO3 thin films produced by pulsed laser ablation-deposition

The surface roughness of PbZrxTi1-xO3 (PZT) produced by pulsed laser ablation-deposition (PLAD) was evaluated as a function of the deposition temperature, oxygen pressure, laser energy density and target-to-substrate distance. Quantitative and qualitative results were obtained by scanning the surface of PZT with an atomic force microscope. The normalized root-mean-square roughness decreases as the magnitudes of the four process variables are increased. The improvement in the surface roughness with an increase in all the process parameters, except the laser energy density, can be explained qualitatively in terms of the particle energetics required for surface activation to occur. The decrease in roughness with increasing laser energy density implies that partially dissociated ejecta are completely vaporized as the laser energy density is increased.