US Patent 11430510 Multi-level ferroelectric field-effect transistor devices

A device comprises a non-volatile memory and a control system. The non-volatile memory includes an array of non-volatile memory cells, wherein at least one non-volatile memory cell includes a ferroelectric field-effect transistor (FeFET) device. The FeFET device includes first and second source/drain regions, and a gate structure which comprises a ferroelectric layer, and a gate electrode disposed over the ferroelectric layer. The ferroelectric layer comprises a first region adjacent to the first source/drain region and a second region adjacent to the second source/drain region. The control system is operatively coupled to the non-volatile memory to program the FeFET device to have a logic state among a plurality of different logic states. At least one logic state among the plurality of different logic states corresponds to a polarization state of the FeFET device in which the first and second regions of the ferroelectric layer have respective remnant polarizations with opposite polarities.