Crystallization of amorphous (Pb, La) (Zr, Ti) O-3 thin film and its electrical properties

Dense amorphous PLZT films with composition (Pb9.925La0.075) (Zr0.4La0.6) O -3 were deposited on Pt/MgO (100) substrates by rf-magnetron sputtering wit hout heating the substrates and were subsequently crystallized by postdepos ition annealing. The optimum conditions in the two-step annealing process t o crystallize the amorphous PLZT films were investigated. The post-depositi on-annealed films showed excellent crystallinity and c-axis orientation whe n the amorphous PLZT films were annealed in an oxygen flow at a soaking tem perature for the initial nucleation process of T-1=300 degreesC, a temperat ure for crystal growth process of T-2=750 degreesC, and the T-2-soaking tim e of t(2)=60 min. Conventional Pt/PLZT/Pt capacitors were fabricated by for ming Pt top electrodes on crystallized 300-nm-thick PLZT films. The remanen t polarization and the coercive field of the present capacitors, which indi cated almost symmetric P-E hysteresis loops, were 2P(r)=30 muC/cm(2) and 2E (c)=90 kV/cm, respectively. The high-endurance PLZT capacitors with excelle nt ferroelectric properties produced by the present optimized crystallizati on have great potential for application to nonvolatile memory devices.