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

Abstract

Interfacial layers near top and bottom electrodes with low resistivity in Pb (Zr0.4 Ti0.6) O3 (PZT) thin film are identified and modeled through frequency-dependent polarization-voltage (P-V) hysteresis loops at frequencies below 20 kHz. 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±2 nm for an IrIr O2 PZTPtSi O2 Si capacitor with a PZT film thickness of 100 nm, in good agreement with the resistive measurements by Chu [Appl. Phys. Lett. 81, 5204 (2002)]. © 2005 American Institute of Physics.