Experimental determination of interfacial-layer thickness from polarization-voltage hysteresis loops in Pb(Zr0.4Ti0.6)O3 thin films

Abstract

Interfacial layers near top and bottom electrodes with low resistivity in Pb(Zr0.4Ti0.6)O3 (PZT) thin film are identified and modeled through frequency-dependent polarization-voltage (P-V) hysteresis loops at frequencies below 20kHz. Actual voltage drops, as well as built-in imprint voltage across the intrinsic ferroelectric layer, are found to be frequency dependent, as shown from the linear voltage shift of P-V hysteresis loops against applied external voltage at different frequencies with respect to one referenced hysteresis loop. Calculated interfacial-layer thickness is about 32±2nm for an Ir∕IrO2∕PZT∕Pt∕SiO2∕Si capacitor with a PZT film thickness of 100nm, in good agreement with the resistive measurements by Chu et al. [Appl. Phys. Lett. 81, 5204 (2002)].