Hysteretic metal–ferroelectric– semiconductor capacitors based on PZT/ZnO heterostructures

Abstract

Interfacing of ferroelectric and semiconductor materials provides a means of coupling unique properties associated with ferroelectric materials to high performance semiconductor devices. In this work we report the electronic properties of ferroelectric/ZnO heterostructures, where (Pb,Zr)TiO3 (PZT) is used as a prototypical ferroelectric oxide. Metal–PZT–metal structures demonstrate ferroelectric hysteresis with remanent polarization of 28 µC cm−2 and coercive field of 75 kV cm−1 for a loop of 15 V. The metal–PZT–ZnO capacitor structures demonstrate a characteristic metal–insulator–semiconductor capacitance–voltage (C–V) behaviour with a hysteretic memory window of approximately 4 V. The heterostructure C–V characteristics do not change significantly with varying frequency. Metal–PZT–ZnO capacitors are also used as part of a simple RLC circuit to demonstrate the ability to shift resonant frequency of the circuit with switching ferroelectric polarization.