CORRELATION BETWEEN CRITICAL COERCIVE FIELD AND RESIDUAL STRESS IN ANTIFERROELECTRIC PZT 95/05 FILMS

Two types of antiferroelectric Pb(Zr0.95Ti0.05)O-3 (PZT 95/05) films having a single layer thickness of either 50 nm/layer or 200 nm/layer were fabricated and their antiferroelectric properties studied. The films were derived via chemical solution deposition (CSD). A difference in the critical coercive field between films with similar total thickness but different single layer thickness was found. Films having 200 nm thick single layers required lower electric field to switch from antiferroelectric to ferroelectric phase. The residual stress, determined for both types of films, showed much lower values for films made with 200 nm thick single layers. The other type of film (50 nm/layer) showed a thickness-dependent residual stress, coercive field and dielectric constant. At low thickness (<0.5 mu m) residual stress up to 600 MPa was determined, which decreased to around 180 MPa upon further thickness increase. A similar trend was found for the dielectric constant with initially high values decreasing with increasing thickness. It was concluded that there is a correlation between the residual stress and critical coercive field.