Patent ID: 7031180

Claim:
A method of reading data in a ferroelectric memory device, comprising: applying a read voltage to a ferroelectric capacitor; and detecting a voltage that reflects an amount of a dynamic change in capacitance of the ferroelectric capacitor to which the read voltage is applied, the ferroelectric capacitor stores one of first data and second data, the first data being stored based on spontaneous polarization of a first polarity when a voltage applied to the ferroelectric capacitor is returned from a write voltage of the first polarity to 0 V, the second data being stored based on spontaneous polarization of a second polarity when the voltage applied to the ferroelectric capacitor is returned from a write voltage of the second polarity to 0 V, and polarity of polarization of the ferroelectric capacitor which has stored the first data is not reversed, and polarity of polarization of the ferroelectric capacitor which has stored the second data is reversed, when a voltage of the first polarity is applied to the ferroelectric capacitor as the read voltage.