Piezoresponse force microscopy studies of PbTiO3 thin films grown via layer-by-layer gas phase reaction

We fabricated 20 nm thick PbTiO3 films via reactive magnetron sputtering and studied the domain switching phenomena and retention properties using piezoresponse force microscopy. We found that multistep deposited PbTiO3 thin films showed 29% smaller rms roughness (2.5 versus 3.5 nm), 28% smaller coercive voltage (1.68 versus 2.32 V), 100% higher d33 value, and improved retention characteristic (89% versus 52% of remained poled domain area in 1280 min after poling) than single-step deposited PbTiO3 thin films. We attribute the improvement to the more complete chemical reaction between PbO and TiO2 during the film growth.