A ferroelectric field effect transistor based on a Pb(ZrxTi1−x )O3/SnO2 heterostructure

Abstract

The possibility of fabricating a ferroelectric FET based on a Pb(Zr_xTi_1−x )O₃/SnO₂ (PZT/SnO₂) heterostructure is investigated. Sb-doped epitaxial SnO₂/Al₂O₃ thin film deposited by YAG laser ablation from a metal target is used as the FET channel. The highest obtained electron mobility in the channel is 25 cm²/(V s) at an electron density of 8 × 10¹⁹ cm⁻³. The possibility of growing PZT film directly on SnO₂ film using two different techniques, laser ablation and magnetron sputtering, is demonstrated. Both methods have been used in the fabrication of Au/PZT/SnO₂ capacitor heterostructures, whose top Au electrode is 250×250 μm² in size. These cells demonstrate a capacitance of 1000 pF at a 10-V bias and remnant polarization up to 16 μC/cm². A Au/PZT/SnO₂/Al₂O₃ transistor structure with 94% modulation of the channel current is fabricated. The difference in the channel current under the effect of positive and negative remnant polarization of the undergate ferroelectric is 37%.