Top-gate ferroelectric thin-film-transistors with P(VDF-TrFE) copolymer

Low-voltage top-gated ferroelectric polymer memory thin-film-transistors (TFTs) have been fabricated using a poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] and an amorphous conjugated polymer poly(9,9-dioctylfuorene-co-bithiophene) (F8T2) as the gate dielectric and semiconducting layer, respectively. TFTs having amorphous semiconducting polymers such as F8T2 exhibit near perfect yield due to their smooth surface morphology. The transfer curves of the fabricated TFTs exhibited counter-clockwise hysteretic behaviors, which is a result of the ferroelectric nature of P(VDF-TrFE). Memory transistors using Ni/P(VDF-TrFE)/F8T2 exhibit promising behaviors such as a memory window of 2.5 V at VG of 5 to −10 V, four orders-of-magnitude of ON/OFF ratio, and gate leakage current of 10−10 A.