Effects of silicon Interface and frequency dependence in solution-processed high-K poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) dielectric characteristics

A solution-based ferroelectric relaxor poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) terpolymer, P(VDF–TrFE–CTFE), is employed in a metal-insulator-semiconductor (MIS) capacitor as a high-k dielectric material. Based on experimental characterizations, the capacitance of the MIS structure is decreased with P(VDF-TrFE-CTFE) thickness reduced. Examined by electrical characterizations, an equivalent interface layer at the P(VDF-TrFE-CTFE)/silicon interface is proposed in this work. This shows that the P(VDF–TrFE–CTFE) film thickness is an important factor while using it as a high-k dielectric material in devices. At the same time, experimental results also show a low remnant polarization and low coercive field of 1.23μC/cm2 and 0.176MV/cm, respectively. This indicates operating frequency is also a factor of its effective dielectric constant. In our experimental results, the maximum dielectric constant is 32.4 at 1kHz with 2900nm film thickness. For applications in different organic electronics, therefore, this study demonstrates that P(VDF–TrFE–CTFE) is a frequency/thickness dependent high-k dielectric material.