Transient-current measurement of the trap charge density at interfaces of a thin-film metal∕ferroelectric∕metal structure

A method providing estimation of the trap density at metal∕ferroelectric interfaces of a depleted ferroelectric film located between back-to-back Schottky barriers has been developed. The method is based on the recharge of interface traps induced by external bias pulse applied to the metal∕ferroelectric∕metal structure. It is shown that the transient current under bias pulse can be controlled by the trap recharge on the reverse-biased interface. Using the method, the trap charge density on interfaces of the Pt∕PZT∕Ir(Ti∕SiO2∕Si) capacitor was found from transient-current measurements to be two orders of magnitude less than the remnant polarization of PbZrxTi1−xO3 film.