Ferroelectric memory device

A ferroelectric memory device comprising:

• a substrate;
• a ferroelectric structure disposed on the substrate, wherein the ferroelectric structure comprises
• a first ferroelectric material layer disposed on the substrate,
• an electrical floating layer disposed on the first ferroelectric material layer, and
• a second ferroelectric material layer disposed on the electrical floating layer;
• and
• a gate electrode layer disposed on the ferroelectric structure,
• wherein a hysteresis loop of the second ferroelectric material layer differs from a hysteresis loop of the first ferroelectric material layer, and
• wherein the first ferroelectric material layer, the electrical floating layer, the second ferroelectric material layer, and the gate electrode layer are sequentially stacked;
• wherein the first and second ferroelectric material layers each comprise the same metal oxide and each comprise one or more dopants, and
• wherein the one or more dopants of the first ferroelectric material layer differ from the one or more dopants of the second ferroelectric material layer;
• wherein the metal oxide comprises at least one of a hafnium oxide, a zirconium oxide, and a hafnium zirconium oxide;
• and
• wherein the electrical floating layer is disposed between the first ferroelectric material layer and the second ferroelectric material layer, and wherein only the first ferroelectric material layer contacts the substrate.