Fabrication and characterization of ferroelectric field effect transistor

Abstract

v, 103 leaves : ill. ; 30 cm.PolyU Library Call No.: [THS] LG51 .H577M AP 2001 SoManganese oxide La0.7Sr0.3MnO3 (LSMO) films and all-perovskite epitaxial Pb(Zr0.52Ti0.48)O3 (PZT)/La0.7Sr0.3MnO3 heterostructure on single crystal LaAlO3 (LAO) substrates have been fabricated by Pulsed Laser Deposition (PLD) method. It is found that the electrical transport properties of LSMO is very sensitive to the film's oxygen content, which can be tuned easily during deposition by controlling the ambient oxygen pressure. They are, however, very stable and remain unchanged in further thermal treatments. Epitaxial LSMO films are obtained at processing temperature as low as 500oC. Excellent crystalline quality of PZT(500 nm)/LSMO(40 nm) heterostructures have been realized. High remnant polarization (48 uC/cm2), low coercive field (57 kV/cm), low polarization loss (~8% up to 2x109 switching cycles) and long retention (>105s) are demonstrated for the ferroelectric PZT films. The leakage current in the Au/PZT/LSMO structure is about 5X10-7 A/cm2. The results of both structural and electrical properties of PZT/LSMO heterostructures show that this material system is a suitable candidate for use in non-volatile ferroelectric field effect transistor (FeFET). A small remnant field effect modulation (5.6%) has been obtained and further optimizations in developing FeFET are using PZT/LSMO heterostructures suggested.Department of Applied PhysicsM.Phil., Dept. of Applied Physics, The Hong Kong Polytechnic University, 2001