Textures of Ferroelectric BLT Films for Semiconductor Memories by Electron Backscatter Diffraction and Piezo-response Force Microscope

摘要

Issues of ferroelectric high-density memories ( > 64Mb) indispensable for upcoming ubiquitous era have been on the cell integration less than 0.1um~2 and reliabilities. Thus nanoscale control of microstructures of ferroelectric films with large switching polarization has been one of the issues to obtain the uniform electrical properties for realization of high-density memories. In this study the grain orientations and distributions of BT-based films by spin-on coatings were examined by EBSD (electron backscatter diffraction) technique. Ferroelectric domain characteristics by PFM (piezo-response force microscope) were also performed to study the dependence of reliabilities on the grain orientations and distributions. It is believed that understandings of the nucleation and growth mechanisms of the a- or b-axis oriented films during the thermal processes such as RTA and furnace annealing affecting on grain orientation and uniformity could be possible based on this experimental results.