| 摘要 |
PROBLEM TO BE SOLVED: To stabilize a reference voltage regardless of the variation in characteristics which is produced at the time of manufacture and after a long term usage by a method wherein a voltage which is obtained by adding a minimum voltage enabling the reading of a signal voltage generated by signal charge in a memory cell in a non-reverse state to the signal voltage. SOLUTION: A data '0' is written in dummy memory cell capacitors DFC11, DFC21, DFC12 and DCF22 beforehand. In a reading operation, a data is outputted to a bit line BL1 from a ferroelectric memory cell MC11. Signal charge corresponding to the data '0' is outputted to a bit line/BL1 from the capacitor DFC21 of a dummy memory cell DC1. Further, by the capacitance coupling with a dummy memory cell plate line DPL2 through a dummy memory cell capacitor 41, the voltage of the bit line/BL1 is elevated to a value higher than the threshold voltage of a sensing amplifier circuit SAMP1. |
