Development of manipulation technology of ferroelectric polymer film: Photo-lithographic patterning and multilayer formation

Abstract

The micrometer-scale patterning of ferroelectric polymer film of poly(vinylidene fluoride-trifluoroethylene) was performed using an ordinary photo-lithographic method with a commercialized photoresist, developer and photoresist stripper. To hinder the ferroelectric polymer film from dissolving at the photoresist stripper, the solubility of the photoresist stripper was controlled by dilution with an insoluble solvent, in this case water. In addition, patterning of the top electrode on the ferroelectric polymer film was completed by a lift-off process, which also used the diluted photoresist stripper. From the polarization-voltage relationships, no thermal and chemical degradation was found during the patterning and lift-off process. Another new process for the multilayer formation of ferroelectric polymer film was performed by a detach-and-transfer method with ferroelectric polymer film. From the polarization-voltage relationships, ferroelectricity was shown in detach-and-transferred ferroelectric polymer film. Therefore, it is concluded that the two conditions of photolithographic patterning and the multilayer formation of ferroelectric polymer film were established successfully and that these methods will be helpful for variable device fabrications and applications with ferroelectric polymer film. (C) 2011 Elsevier B.V. All rights reserved.