Growth of piezoelectric thin films with fine grain microstructure by high energy pulsed laser deposition

Thin piezoelectric films of lead zirconate-titanate (PZT) were deposited by pulsed laser ablation from prepared PZT targets and compared with films ob tained from commercial samples. The special targets were obtained from nano sized powders synthesised by spray-drying of precursor solution and sintere d at 700 degrees C. The depositions were performed on Si (100) substrates c arefully cleaned and heated in a vacuum chamber at 400 degrees C. The same experimental set-up (Nd-YAG laser, 0.3 J/pulse, 1064 nm, 10 ns, 10 Hz) and parameters (reactive O-2 atmosphere of pressure 150 mTorr, substrate temper ature 370 degrees C) were used for all the films. After deposition samples were investigated by X-ray diffraction, scanning electron microscopy and en ergy dispersive spectroscopy (EDS). Similar analysis were performed on targ ets before and after deposition. It has been observed that the evolution of the two types of targets during deposition was very different and this asp ect was reflected in differences of film morphologies. Films deposited from special targets presented an uniform fine grained microstructure with only few particulates on surface, while films deposited from commercial targets had a much rougher surface. EDS analysis showed important chemical differe nces between these particulates and the surrounding film. (C) 1999 Elsevier Science S.A. All rights reserved.