Study of pulsed laser deposited lead lanthanum titanate thin films

Paraelectric lanthanum doped lead titanate (PLT) thin films for high permit tivity material applications were grown on Pt-coated Si-substrates by the l aser ablation technique. A rapid thermal annealing (RTA) process was adopte d to induce crystallization and a polycrystalline fine microstructure was o btained. The dielectric properties, capacitance-voltage (C-V) characteristi cs and polarization hysteresis (P-E) with temperature were studied. The die lectric constant was approximately 720 while the dissipation factor was app roximately 0.04 at room temperature for a 0.9-mum thick film at 100 kHz fre quency. Hysteresis behavior was observed in C-V and P-E responses and was a ttributed to the presence of charge accumulation either in the grain bounda ries or in the electrode-film interface. The charge storage density aspect was studied for DRAM applications and the obtained charge storage density a t 6 V was 4.5 pC/cm(2). The density of surface charge states was approximat ely 10(13) cm(2)/eV at room temperature and the effect of temperature and f requency was studied and correlated with the properties of the film. (C) 20 01 Elsevier Science B.V. All rights reserved.