Force-Electric Coupling of Nanoscale Ferroelectric Domains Based on Piezoelectric Force Microscopy (PFM)

Abstract

Piezoelectric and ferroelectric materials are widely used in various types of microelectronics due to their excellent mechanical and electrical coupling characteristics. In recent years, piezoelectric force microscopy has developed into a powerful tool for analyzing nanoscale ferroelectric materials. However, quantitative analysis based on PFM is difficult to properly study it. This article studies the related issues of PFM quantitative analysis. First, the relationship between the effective piezoelectric coefficient and piezoelectric coefficient of different materials is analyzed from the PFM nanometer scale to analyze the force-electric coupling effect. The study found that the effective piezoelectric coefficient is closely related to the intrinsic electroelastic constant of the material. Secondly, the analysis of the nanoscale piezoelectric deformation of ferroelectric materials shows that under the conductive SPM probe, as the clustering with the probe increases, the in-plane displacement first increases and then decreases, and the out-of-plane displacement gradually decreases. Finally, the half-width region of the nanoscale ferroelectric response domain was analyzed by PFM. Taking the in-plane and out-of-plane domains of 180° and 90° domains as examples, the relationship between the response boundary domain and the tip radius was analyzed, and the results showed that whether the PFM can effectively solve the problem of detection and analysis depends on the half-width of the response boundary domain, and the resolution of the vertical PFM is higher than that of the lateral PFM.