įeFET based memory devices are read using voltages below the coercive voltage for the ferroelectric.

In the late 1980 Ferroelectric RAM was developed, using a ferroelectric thin film as capacitor, connected to an addressing FET. Early field effect transistor based devices used bismuth titanate (Bi 4Ti 3O 12) ferroelectric, or Pb 1−xLn xTiO 3 ( PLT) and related mixed zirconate/titanates ( PLZT). Further research occurred in the 1960s, but the retention characteristics of the thin film based devices was unsatisfactory. Use of a ferroelectric ( triglycine sulfate) in a solid state memory was proposed by Moll and Tarui in 1963 using a thin film transistor. Its structure was like that of a modern inversion channel MOSFET, but ferroelectric material was used as a dielectric/insulator instead of oxide. In 1955, Ian Munro Ross filed a patent for a FeFET or MFSFET.

Permanent electrical field polarisation in the ferroelectric causes this type of device to retain the transistor's state (on or off) in the absence of any electrical bias.įeFET based devices are used in FeFET memory - a type of single transistor non-volatile memory. A ferroelectric field-effect transistor ( Fe FET) is a type of field-effect transistor that includes a ferroelectric material sandwiched between the gate electrode and source-drain conduction region of the device (the channel).

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