发明名称 |
Non-volatile semiconductor memory device |
摘要 |
A non-volatile semiconductor memory device includes a plurality of memory cells each including a capacitor as a memory element, the capacitor sandwiching a ferroelectric member. The non-volatile semiconductor memory device further includes: a first counter for counting the number of write accesses and read accesses for writing or reading first logic data to each one of the plurality of memory cells; a second counter for counting the number of write accesses and read accesses for writing or reading second logic data to the memory cell; and a refresh control circuit for performing, when either a first value counted by the first counter or a second value counted by the second counter exceeds a predetermined value, a refresh operation by applying electric fields for causing a polarization state of the ferroelectric member of the capacitor to make a complete round on a hysteresis curve of the ferroelectric member in a corresponding one of the plurality of memory cells for which the first or second value counted by the first counter or the second counter has exceeded the predetermined value.
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申请公布号 |
US5777921(A) |
申请公布日期 |
1998.07.07 |
申请号 |
US19970821024 |
申请日期 |
1997.03.19 |
申请人 |
SHARP KABUSHIKI KAISHA |
发明人 |
TAKATA, HIDEKAZU;TANAKA, HIDEHIKO |
分类号 |
G11C14/00;G11C7/00;G11C11/22;G11C11/406;(IPC1-7):G11C11/22 |
主分类号 |
G11C14/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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