抄録
Recently, ferroelectric random access memory (FeRAM) with a metal/ ferroelectric/ metal/ insulator/ semiconductor field-effect transitors (MFMIS-FET) structure have been studied extensively because of various advantages such as the miniaturization of memory cell and non-destructive read out.In order to attain the sufficient application of external voltage to ferroelectrc layer, ferroelectrics need to have low dielectric constant. Sr2(Nb,Ta)2O7 type compound is one of the candidates for ferroelectric layer in MFMIS-FET structure because of its low dielectric constant and Pb- and Bi-free composition. In this work, fabrication and characterization of Ca-substituted Sr2(Nb,Ta)2O7 thin films on various substrates could be carried out by chemical solution deposition method. Homogeneous and stable precursor solutions were prepared by controlling the reaction of starting metal alkoxides. (Sr,Ca)2(Nb,Ta)2O7 thin films could successfully be synthesized with high crystallinity on Pt/ Ir/ Ti/ SiO2/ Si substrates. Electrical properties of prepared (Sr,Ca)2(Nb,Ta)2O7 thin films were also evaluated.
