发明名称 |
Method for preventing sub-threshold leakage in flash memory cells to achieve accurate reading, verifying, and fast over-erased Vt correction |
摘要 |
The present invention provides a method for preventing sub-threshold leakage in flash EPROM cells during Vt repair, read and verify operations. The present invention prevents sub-threshold leakage by either biasing the floating gate voltage of non-selected cells to a level that is less than the sources voltage. This biasing is achieved by controlling the voltages applied to such non-selected cells bitline and wordline voltages, or by floating the non-selected sourcelines to electrically disconnect the sourcelines of the non-selected cells. This method allows fast and accurate Vt repair of cells while avoiding Vt degradation of non-erased and repaired cells due to subthreshold current leakage, as well as reduced sub-threshold leakage during read and verify operations.
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申请公布号 |
US5856945(A) |
申请公布日期 |
1999.01.05 |
申请号 |
US19970906198 |
申请日期 |
1997.08.05 |
申请人 |
APLUS FLASH TECHNOLOGY, INC. |
发明人 |
LEE, PETER W.;HSU, FU-CHANG;TSAO, HSING-YA |
分类号 |
G11C11/56;G11C16/04;G11C16/34;H01L27/115;(IPC1-7):G11C16/04;G11C16/06 |
主分类号 |
G11C11/56 |
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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