Preparation of Piezoelectric PZT-PZN Thick Films on Si by Low Temperature Firing
Katsuhiko TANAKA, Teppei KUBOTA, Kazuhiro YAMADA and Yukio SAKABE
Abstract:The improvement of piezoelectric thick films formed on Si substrates is required to develop piezoelectric microactuators. In fabricating Pb(Zr,Ti)O3-Pb(Zn,Nb)O3 (PZT-PZN) films on Si, it is important to lower the firing temperature of thick films and use buffer layers on Si to prevent the reaction of Si and Pb in the PZT-PZN films. Two kinds of additives, PbO-Ge2O3 (PGO) and Bi2O3-ZnO, were evaluated to obtain dense films by firing at a low temperature of 850Ž. Buffer layers of Al2O3/SiO2 and Al2O3/TiO2/SiO2 were also evaluated from point of view of densification and electrical properties of the films. The ferroelectric and piezoelectric properties increased as the films became denser, and excellent properties were obtained as follows for films with B2O3-ZnO additives formed on Pt/Al2O3/TiO2/SiO2 -coated Si: dielectric constant 1350, Curie temperature 300Ž, remanent polarization 30.9 ƒÊC/cm2 and piezoelectric constant d31 121 pm/V. Key Words:Piezoelectric, Ferroelectric, Pb(Zr,Ti)O3-Pb(Zn,Nb)O3, Thick Film, Screen Printing, Piezoelectric Actuator