Chemical Solution Deposition of BiFeO3 Films with Layer-by-Layer Control of the Coverage and Composition

Chemical solution deposition of BiFeO3 thin films is one of the most commercially available techniques to produce large-scale low-cost coatings for further application in memory devices. In this contribution, we implemented piezoresponse force and conductive atomic force microscopies to study the layer-by-layer sol-gel deposition of BiFeO3 thin films focusing on the local phase distribution, morphology, piezoelectric response, and leakage current. The final properties of resulting thin films are found to be determined not only by the composition of the gel and crystallization step but by the gelation step as well. The drying temperature and treatment duration of the solution are shown to drastically influence the film coverage, which finally determines the morphology of the films and behavior of the crystallization process.