| 摘要 |
PROBLEM TO BE SOLVED: To prevent data written at the manufacturing process from vanishing at the subsequent heating process. SOLUTION: A ROM area of the ferroelectric memory is provided with a pair of memory cells having a pair of ferroelectric capacitors wherein the data of logical levels reverse to each other are written. After the ferroelectric capacitors are formed at the manufacturing process, prescribed data are written into the ferroelectrfic capacitors in the ROM area. After that, a baking process is executed for the prescribed time. The inprint of the ferroelectric capacitors in the ROM area is advanced by the baking process, and the read-out margin being the difference in residual polarized values of the ferroelectric capacitances is increased. Thus, the data to be preliminarily stored in the ROM area in the manufacturing process are surely read out. That is, the data to be preliminarily stored in the ROM area are prevented from vanishing. COPYRIGHT: (C)2004,JPO
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