| 摘要 |
PROBLEM TO BE SOLVED: To provide a ferroelectric random access memory device comprising a reference circuit generating reference voltage being variable in accordance with variation in a polarization state of a ferroelectric capacitor of a memory cell caused by elapse of a time. SOLUTION: The reference circuit of this invention is used as a circuit generating reference voltage in a non-volatile semiconductor memory device, namely, in a ferroelectric random access memory device. This reference circuit comprises a polarization state discriminating circuit, a decoder circuit, and a reference voltage generating circuit. The polarization state discriminating circuit generates a pass/fail signal informing the extent of variation in a polarization state of a ferroelectric capacitor generated as elapse of a time by using a dummy cell having a ferroelectric capacitor. A pass/fail signal generated, thus is decoded by the decoder circuit, the reference voltage generating circuit generates internally reference voltage having mutually different levels by utilizing power source voltage, and outputs one out of these reference voltage by utilizing this pass/fail signal as selection information.
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