The embodiment of the invention discloses a
semiconductor memory, a ferroelectric
field effect transistor and a ferroelectric
film capacitor. The ferroelectric
field effect transistor comprises a substrate, a source
electrode, a drain
electrode, an insulating layer, a first ferroelectric layer, an interlayer, a second ferroelectric layer and a grid
electrode layer, the source electrode and the drain electrode are formed in the substrate, the insulating layer is located on the substrate, the projection of the insulating layer is located between the source electrode and the drain electrode, and the first ferroelectric layer, the interlayer, the second ferroelectric layer and the grid electrode layer are sequentially arranged on the insulating layer. The
conduction band bottom of the interlayer is higher than or equal to the
conduction band bottoms of the first ferroelectric layer and the second ferroelectric layer, and the difference between the
conduction band bottoms is smaller than or equal to 0.3 eV. The
valence band top of the interlayer is lower than or equal to the
valence band tops of the first ferroelectric layer and the second ferroelectric layer, and the difference between the
valence band tops of the first ferroelectric layer and the second ferroelectric layer is smaller than or equal to 0.3 eV. According to the embodiment of the invention, charge
trapping is inhibited through energy
band engineering, so that the anti-fatigue characteristic of the ferroelectric layer can be improved, and the performance of a corresponding element is improved.