A metal-insulator-semiconductor (Mis) device using a ferroelectric polymer thin film in the gate insulator

A nonvolatile MIS memory device using a ferroelectric polymer thin film in the gate insulator is proposed. In the gate electrode of the device, a ferroelectric polymer thin film is sandwiched between two insulator films to prevent carrier injection into the polymer thin film. Al-SiO₂-P (VDF/TrFE)-SiO₂-Si capacitors were fabricated to evaluate the basic characteristics of the device by C- V measurement, and ferroelectric polarization reversal was observed in the capacitors. Based on the C-V measurements, MIS transistors were fabricated using a process which virtually self-aligns the effective gate area to the source/drain. It was shown that the MIS transistor could be electrically programmed and erased. The on/off ratio of the transistor was greater than 10⁶.