Relationship between PB content, crystallographic texture and ferroelectric properties of plzt thin films for FRAM® applications

Abstract

In order to have better control of ferroelectric properties and fast PLZT thin film quality control monitoring during FRAM processing, a correlation between ferroelectric performance, Pb content and crystallographic texture needs to be established for RF magnetron sputtered PLZT thin films. The ferroelectric performance of 200 nm PLZT thin films that contain different levels of Pb excess and different volume fractions of {100} textured materials were investigated. It was found that a higher Pb excess in the as-sputtered PLZT film leads to a higher volume fraction of {100} textured crystallites after annealing. Highly {111} textured PZT thin films show a relatively high Q_sw (≍2Pr), however the fatigue and the aging performance is not optimized. The optimized range for the volume fraction of {100} textured material was identified. PLZT thin films, of which the {100} volume fraction is in die optimized range, exhibit improved fatigue and aging performance, better suited for FRAM application.

Key Words:

• ferroelectric thin films
• ferroelectric capacitors