Separation of Near Interface Regions From Central Bulk in a Ferroelectric Thin Film

The fabrication and operation of a ferroelectric thin film capacitor may change the electric properties of the material layers next to the top and bottom electrodes through various processes, such as chemical reaction and diffusion. The existence of these near interface regions (NIRs) can have significant effect on the device performance and imposes a limit on the minimum thickness of a functional film. It is of both basic and practical interest to separate the NIRs from the central bulk region (CBR) of a film and characterize the related thickness and resistivity. Based on the understanding that the NIRs should be the same for the films of the same composition under the same process conditions, we developed a method to separate the NIRs from the CBR. Using sol-gel fabricated PLZT films with different metal contacts, Pt and Ir, as an example, we demonstrate how to quantify the thickness of the NIRs and the CBR resistivity. The experimental data show good agreement with the model. Our results reveal that (...