Factors for the polarization lifetime in metal–ferroelectric–insulator–semiconductor capacitors

Depolarization field in metal–ferroelectric–insulator–semiconductor (MFIS) capacitors with a ferroelectric–electrode interface layer was derived theoretically in this work. The polarization relaxation characteristics were investigated in details based on Lou’s polarization retention model. It is found that the retention time of ferroelectric field-effect transistors (FETs) can be affected significantly by the dielectric constant and the thickness of ferroelectric thin film, and by the interface layer thickness. The results may provide some insights into the design and the retention property improvement of MFIS–FET as nonvolatile memory.

► We studied the polarization relaxation characteristics in MFIS capacitors. ► Enhancing the permittivity of ferroelectric can improve the retention property. ► Using relatively thicker ferroelectric can improve the polarization retention time. ► The ferroelectric–electrode interface may be a key reason for short retention time.