Effects of Sputter-Deposited LaNiO 3 Electrode on the Deposition and Properties of Ferroelectric Thin Films

Highly (100)-textured thin film of metallic LaNiO 3 (LNO) was grown on the Pt/Ti/SiO 2 /Si substrates by rf magnetron sputtering at ˜300°C, which was used as a bottom electrode to prepare highly (100)-textured ferroelectric films. Examples on the deposition of PbTiO 3 , (Pb l−x La x )TiO 3 , Pb(Zr 0.53 Ti 0.47 )O 3 , Pb[(Mg 1/3 Nb 2/3 ) 1−x Ti x ]O 3 , and (Ba 1−x Sr x )TiO 3 thin films by rf magnetron sputtering or sol-gel method are shown. A reduction of temperature for perovskite phase formation can be achieved, especially for those difficult to crystallize. The surface roughness of the ferroelectric films is also improved as compared to that of films deposited on conventional Pt electrode. Although the electrical properties of the ferroelectric films are affected by the out-diffusion of LNO when a higher temperature was used in the preparation of the films, under an appropriate processing condition, the highly (100)-textured films can have satisfactory electrical characteristics for application. Moreover, the polarization-fatigue property can be also improved by the use of LNO electrode.