Evaluation of interfacial-layer capacitance from fast polarization retention in ferroelectric thin films

We distinctly identify interfacial layers with damaged ferroelectricity within Pt/Pb(Zr0.4Ti0.6)O-3/Pt/Ti/SiO2/Si thin-film capacitors on the basis of fast polarization retention. The retention that deteriorates with the decrease of film thickness arises from the increase of depolarizing field across the ferroelectric layer. The depolarizing field backswitches partial domains into their previous orientations after the applied voltage. Numerical modeling through discharging of polarization charges within interfacial layers yields the interfacial capacitance density of 0.33 +/- 0.05 F/m(2), independent of the electrode size and film thickness. (c) 2007 American Institute of Physics.