Patent ID: 6950327
Filing Date: 2005-09-27
Classification: G11C

Abstract:
1. A semiconductor memory device comprising: a ferroelectric capacitor for storing any one of a plurality of logic values such that a plurality of different displacements of a remanent polarization correspond to at least one of said plurality of logic values, while another displacement of the remanent polarization different from each of the plurality of displacements of the remanent polarization corresponds to each of the plurality of logic values other than the at least one logic value; data writing means for applying, to the ferroelectric capacitor, at least one write electric voltage pulse for poling the ferroelectric capacitor in any one of the plurality of displacements and the other displacement and thereby writing any one of the plurality of logic values in the ferroelectric capacitor; and data reading means for applying a read electric voltage pulse to the ferroelectric capacitor, sensing the displacement of the remanent polarization in the ferroelectric capacitor when the read electric voltage pulse is applied, and thereby reading the logic value stored in the ferroelectric capacitor.