FERROELECTRIC MEMORY

PURPOSE:To increase the information quantity per unit cell by providing electrodes on a front side and a rear of a ferroelectric substance, applying a pulse electric field on a specified electrode and generating more than three values of polarization inversion state. CONSTITUTION:A ferroelectric capacitor 3 has a large surface of electrode 6 on the surface of one ferroelectric substance and two pieces of a small surface area of electrodes 7, 8 adjacent to the rear side and the electrodes 7, 8 are connected to reference potential lines 4, 5. The lines 4, 5 hold the voltage pulse applied on them and the electrode 6 is connected to a bit line 1 via the source and the drain of a field-effect transistor FET 9. In the ferroelectric memory, one of the adjacent plural electrodes 7, 8 is specified and a pulse field applied between the electrode 6. Thus more than 3 places of polarization inversion state are obtained and the information quantity per unit of the capacitor 3 can be increased without increasing the cell area.