Top electrode size effect on hysteresis loops in piezoresponse force microscopy of Pb(Zr,Ti)O3-film on silicon structures

• Published in: Journal of applied physics Vol. 112; no. 5
• Main Authors: Bravina, S. L., Morozovsky, N. V., Eliseev, E. A., Morozovska, A. N., Costecalde, J., Soyer, C., Remiens, D., Deresmes, D.
• Format: Journal Article
• Language: English
• Published: 01.09.2012
• Subjects: Dielectrics; Electrodes; Film thickness; Hysteresis loops; Magnetron sputtering; Mathematical models; Microscopy; Platinum
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4746028

Experimental and theoretical studies of hysteresis loops in piezoresponse force microscopy (PFM) directed on elucidating the influence of top electrode lateral sizes on loop peculiarities were performed for Pt/Pb(Zr, Ti)O3/Pt/TiOx/SiO2/Si-substrate structures. The set of top Pt electrodes (50 nm to 10 μm of lateral size) was deposited on the Pb(ZrxTi1−x)O3 film (x = 0.54, thickness ≈1 μm) by RF magnetron sputtering. Under approaching the top electrode lateral size to the film thickness, the transition-like behaviour of PFM response amplitude and coercive tip voltage was observed. The existence of the critical value of dimensionless electrode size parameter γd/h ≈ 1 (γ is the dielectric anisotropy factor, d is the electrode size parameter, and h is the film thickness) was interpreted in the framework of the model based on Landau-Ginzburg-Devonshire theory combined with the decoupling approximation subject to the nonlinear electric field dependence of the ferroelectric polarization and dielectric permittivity.