One of the general features of ferroelectric systems is a complex nature of polarization reversal, which involves domain nucleation and motion of domain walls. Here, time‐resolved nanoscale domain imaging is applied in conjunction with the integral switching current measurements to investigate the mechanism of polarization reversal in yttrium‐doped HfO2(Y:HfO2)—currently one of the most actively studied ferroelectric systems. More specifically, the effect of film microstructure on the nucleation process is investigated by performing a comparative study of the polarization switching behavior in the epitaxial and polycrystalline Y:HfO2thin film capacitors. It is found that although the epitaxial Y:HfO2capacitors tend to switch slower than their polycrystalline counterparts, they exhibit a significantly higher nucleation density and rate, suggesting that this is a rate‐limiting mechanism. In addition, it is observed that under the external fields approaching the activation field value, the switching kinetics can be described equally well by the nucleation limited switching and the Kolmogorov‐Avrami‐Ishibashi models for both types of capacitors. This signifies convergence of two different mechanisms implying that the polarization reversal proceeds via a homogeneous nucleation process unaffected by the film microstructure, which can be considered as approaching the intrinsic switching limit.
The nucleation and growth of cobalt (Co) on blanket Si with extremely thin Co seed was studied in the presence of furil dioxime (FD). Cyclic voltammetry (CV), chronoamperometry, and galvanostatic nucleation studies were conducted to understand the effects of FD on Co nucleation process. A potential dependent suppression effect was observed at low potential with a breakdown of the suppression at high potential, resulting in a hysteresis in CV. The potentiostatic current transient experiments showed that side reactions and adsorption process both greatly affected Co nucleation. A well-established model, which deconvolutes the individual contributions to the total current transient, was applied to fit the experimental curves. Progressive and instantaneous Co nucleation were observed across different FD concentrations and applied potentials. Galvanostatic studies further proved the suppression effect of FD and the effects on film morphology were studied at different conditions.
more » « less- Award ID(s):
- 1662332
- NSF-PAR ID:
- 10302513
- Publisher / Repository:
- The Electrochemical Society
- Date Published:
- Journal Name:
- Journal of The Electrochemical Society
- Volume:
- 167
- Issue:
- 2
- ISSN:
- 0013-4651
- Page Range / eLocation ID:
- Article No. 022509
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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