Epitaxial Pb(Zr₀.₅₂Ti₀.₄₈)O₃/La₀.₃₅Nd₀.₃₅Sr₀.₃MnO₃heterostructures for fabrication of ferroelectric field-effect transistor

Abstract

Epitaxial La₀.₃₅Nd₀.₃₅Sr₀.₃MnO₃(LNSMO) thin films and Pb(Zr₀.₅ ₂Ti₀.₄₈)O₃(PZT)/LNSMO heterostructures have been grown on LaAlO₃(001) substrates by the pulsed laser deposition method. The oxygen concentration in the LNSMO films is quite sensitive to the deposition oxygen pressure and can be controlled during the fabrication process. It is, however, stable against in situ postdeposition thermal treatments. Consequently, the resistivity and the metal-semiconductor transition temperature of the LNSMO films can be tuned and fixed during film growth. Electrical measurements on the Pt/PZT/LNSMO ferroelectric capacitor show a remnant polarization of ~35 μC/cm² and a coercive field of 30–40 kV/cm at low driving voltages. Switching endurance tests suggest no polarization loss up to about 10¹⁰ bipolar switching cycles. The advantages of using epitaxial LNSMO films as the semiconducting channel in an all-perovskite ferroelectric field-effect transistor are discussed.