Thickness Dependence of Ferroelectric Properties for Ferroelectric Random Access Memory Based on Poly(vinylidene fluoride-trifluoroethylene) Ultrathin Films

In this work, switching characteristics of poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) copolymer films are investigated over wide ranges of thickness. It is found that the thickness dependence of the coercive field is in accordance with the classical crystallization model. The leakage current shows a higher value of 140 nC/cm2 as the thickness of P(VDF-TrFE) film is reduced to 50 nm. In addition, an electroactive interlayer has been employed to improve the ferroelectric properties of P(VDF-TrFE) film. After more than 106 cycles of switching, the cell still has good polarization performance at both 25 and 60°C even as the thickness of P(VDF-TrFE) film is down to 50 nm.