Abstract
Yttrium manganate (YMO) thin films were prepared on SiO2 buffered silicon as a candidate for ferroelectric transistor random access memory (FeTRAM). The films were deposited by flash evaporated MOCVD at low temperature and post annealed to crystallize the c-axis oriented hexagonal YMO phase. It is found that oxygen content and substrate temperature are major parameters determining c-axis orientation. For the electrical characteristics, Pr (remnant polarization) ∼2 μ C/cm2 and ϵ (dielectric constant) ∼ 20 are obtained in Pt/YMO/Pt structures. It is also found that a top buffer layer of 30 nm ZrO2 helps to reduce the leakage current of Pt/top buffer/YMO/SiO2/Si stack to 10− 7 A/cm2 and improves the C-V memory window from 0.2 V to 2 V.
ACKNOWLEDGMENTS
This work was supported by the US Missile Defense Agency under contract no. DASG 60-01-C-0046 administrated by the US Army Space and Missile Defense command and partly supported by the US Department of Commerce (NIST) through its Advanced Technology Program (ATP).