Ferroelectric Lead Zirconate Titanate Thin Films Synthesized via a High-Pressure Crystallization Process

Abstract

The crystallization of lead zirconate titanate (PZT) thin films derived from amorphous precursor films has been significantly enhanced using a high-pressure crystallization (HPC) process. By annealing at around 16.5 MPa, well-crystallized PZT thin films were successfully prepared at temperature as low as 350°C which is several hundred degrees centigrade lower than that in the conventional atmospheric annealing process. This novel process considerably reduced the thermal budget and the energy consumption during film processing. During the high-pressure annealing process, the crystallinity and grain size of the annealed films increased with higher annealing temperature and longer annealing time. This developed process effectively suppressed both the outward diffusion of lead species from PZT films into the substrate region and the diffusion of titanium species from the bottom electrodes into the silicon layers. This is because the low annealing temperatures adopted in the high-pressure process reduced the mobility and diffusion rate of the constituent species.