Direct observation of potential distribution across ferroelectric capacitor using off-axis electron holography

Off-axis electron holography was used to observe the potential distribution across a ferroelectric PbZr_x Ti_1-x (PZT) capacitor and the surrounding electric field made by the spontaneous polarization of the polycrystalline PZT (poly-PZT) thin film. I succeeded in applying it to observations of ferroelectric capacitors. The electric potential has been visualized as the contour pattern corresponding to the equi-phase line of the incident electron beam, whose phase shift was due to the electric field of the PZT thin film. This is the first visualization of the poly-PZT thin film of a ferroelectric memory device by means of electron holography