Role of Alumina Buffer Layer on the Dielectric and Piezoelectric Properties of PZT System Thick Films

Abstract

Piezoelectric properties of screen-printed thick films, 0.01Pb(Mg1/2W1/2)O3–0.41Pb(Ni1/3Nb2/3)O3–0.35PbTiO3–0.23PbZrO3 + 0.1 wt% Y2O3 + 1.5 wt% ZnO (PMW–PNN–PT–PZ+YZ) on alumina (Al2O3) buffer layers deposited on Si substrates, were studied. To improve piezoelectric properties of and integrate the PMW–PNN–PT–PZ+YZ thick films, the Al2O3 buffer layers on silicon (Si) substrates were used. The Al2O3 buffer layer on the Si substrate suppressed the pyrochlore phases of the piezoelectric thick films and prevented interdiffusion of Si and Pb. The PMW–PNN–PT–PZ+YZ thick films with 900 nm thick Al2O3 buffer layer showed piezoelectric properties such as Pr = 32 μC/cm2, Ec = 25 kV/cm, and d33 = 32 pC/N. These significant piezoelectric properties of our screen-printed PMW–PNN–PT–PZ+YZ thick films by the Al2O3 buffer layers can be applied to functional thick film in many micro-electromechanical system (MEMS) applications such as micro actuators and sensors.