Observation of Ferroelectricity in Very Thin Vinylidene Fluoride Trifluoroethylene Copolymer[P(VDF·TrFE)] Films by High Frequency C-V Measurements of Al-SiO₂-P(VDF·TrFE)-SiO₂-Si Capacitors

MIS capacitors with Al–SiO 2 –P(VDF·TrFE)–SiO 2 –Si structure were fabricated depositing P(VDF·TrFE) film by a spin coating method to investigate properties of very thin ferroelectric polymer films. By sandwiching the polymer film with SiO 2 films, application of an electrical field high enough for ferroelectricity measurement in several tens nm thick P(VDF·TrFE) films became possible. It is revealed that P(VDF·TrFE) film as thin as 32nm shows ferroelectricity by high frequency C - V measurements of the capacitors.