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

Piezoelectric properties of screen‐printed thick films, 0.01 Pb ( Mg 1/2 W 1/2 ) O 3 –0.41 Pb ( Ni 1/3 Nb 2/3 ) O 3 –0.35 PbTiO 3 –0.23 PbZrO 3  + 0.1 wt% Y 2 O 3  + 1.5 wt% ZnO ( PMW – PNN – PT – PZ + YZ ) on alumina (Al 2 O 3 ) buffer layers deposited on Si substrates, were studied. To improve piezoelectric properties of and integrate the PMW – PNN – PT – PZ + YZ thick films, the Al 2 O 3 buffer layers on silicon (Si) substrates were used. The Al 2 O 3 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 Al 2 O 3 buffer layer showed piezoelectric properties such as P r  = 32 μC/cm 2 , E c  = 25 kV/cm, and d 33  = 32 pC/N. These significant piezoelectric properties of our screen‐printed PMW – PNN – PT – PZ + YZ thick films by the Al 2 O 3 buffer layers can be applied to functional thick film in many micro‐electromechanical system ( MEMS ) applications such as micro actuators and sensors.