The characteristics of a metal–ferroelectric–insulator–semiconductor structure were investigated using poly(vinylidene fluoride/trifluorethylene)(65/35) as a ferroelectric layer and polyvinyl alcohol as an insulating buffer layer. It was found in the metal–insulator–semiconductor structure that the polyvinyl alcohol obtained from 0.4 wt.% solution gave excellent insulator results with a bias sweep range of ± 5 V. The leakage current densities of the polyvinyl alcohol films obtained from 0.1, 0.4 and 0.7 wt.% solutions amounted to 10−5 A/cm2, 10−6 A/cm2 and 10−7 A/cm2, respectively. Based on these results, the 0.4 wt.% polyvinyl alcohol solution was selected for use in the metal–ferroelectric–insulator–semiconductor structures. The width of the memory window in the metal–ferroelectric–semiconductor and metal–ferroelectric–insulator–semiconductor structures measured at a voltage sweep of ±5 V was 2 V and 3 V respectively, whereas the respective current densities amounted to 10−5 and 10−6 A/cm2 at 5V.