Dielectric loss peak due to platinum electrode porosity in lead zirconate titanate thin-film capacitors

Impedance spectroscopy measurements were carried out in situ on lead zirconate titanate capacitors 1.2x1.2 mum(2) in size on a Samsung 4 Mbit 6 in, wafer. We show here that large dielectric loss appears at low frequencies, which is a constriction effect due to the porosity of the platinum electrode. Porous platinum electrodes facilitate an oxygen electrode reaction. The effect may be removed by annealing the platinum electrode at moderate temperature (300 degreesC). Such an anneal should thus be considered an essential step in the fabrication of a ferroelectric thin-film capacitor on Pt. (C) 2002 American Institute of Physics.