Effect of Ferroelectric Polarization on Carrier Transport in Controlled Polarization-Type Ferroelectric Gate Field-Effect Transistors with Poly(vinylidene fluoride-tetrafluoroethylene)/ZnO Heterostructure

摘要

The carrier transport properties of ferroelectric gate field-effect transistors composed of oxide polar semiconductors, ZnO, and organic ferroelectrics, poly(vinylidene fluoride-tetrafluoroethylene) [P(VDF-TeFE)], were investigated. The P(VDF-TeFE)/ZnO heterostructure with a 100-nm-thick channel shows a large ON/OFF ratio of 10~6 in the drain current while that with a channel thickness of 500 nm shows small changes. To clarify the effect of ferroelectric polarization on the carrier transport properties, Hall effect measurement was carried out after poling treatment. Although the Hall mobility for the channel thickness of 500 nm shows no dependence on the poling voltage, that for the channel thickness of 100 nm increases with increasing poling voltage. The temperature dependence of the carrier transport properties indicates that the Hall mobility for the channel thickness of 100 nm increases when the carriers are accumulated at the interface between P(VDF-TeFE) and ZnO, especially below 200 K. The results suggest that the reduction in ionized impurity scattering, which originates from the carrier accumulation due to ferroelectric polarization, increases the mobility.