Evaluation method of ferroelectric capacitor and wafer mounted with evaluation element

摘要

A method is provided for evaluating a ferroelectric capacitor by examining a structure in a prescribed area on a surface of a ferroelectric membrane using a piezo-response mode of a scanning force microscope. The method adopts a layered structure, in which an electrode and the ferroelectric membrane form a pseudo ohmic contact, and comprises the steps of: inducing a localized polarization inversion in a selected crystal grain in the ferroelectric membrane by imposing a voltage pulse having a prescribed polarity; determining a retention time by obtaining a piezo-response image for a prescribed time till a complete inversion of a write domain; and determining a retention characteristic by measuring a time till a complete disappearance of a switched domain or by measuring a time-dependency at a region where the polarization inversion are being retained.