Intrinsic Switching Characteristics of Ferroelectric Ultrathin Vinylidene Fluoride/Trifluoroethylene Copolymer Films Revealed Using Au Electrode

Time-domain measurements of ferroelectric polarization reversal were conducted for spin-coated ultrathin vinylidene fluoride/trifluoroethylene copolymer films deposited with an Au electrode. It was found that full polarization reversal occurs in 50-330-nm-thick films that have switching time independent of the film thickness. We conclude that the thinning-induced increase in switching time reported previously is not a general feature of this copolymer but is specific to an Al-electrode-deposited sample. The intrinsic switching characteristics revealed here include the broadening of the switching time distribution with thinning, which is attributed to the nonuniform electric field caused by surface roughness.