Non-volatile semiconductor memory device
US6907497B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2002 |
| Grant date | Jun 14, 2005 |
| Priority date | — |
| Expiry date | Sep 10, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/3459
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A non-volatile semiconductor memory device includes a memory cell array, a data hold circuit, and a controller A program control function applies a program voltage to a selected memory cell to let data shift from a first logic state to a second logic state. A program verify control function verifies that a programmed data of the selected memory cell shifted to the second logic state. An erratic program verify control function checks that a threshold voltage of a memory cell to be held in the first logic state does not exceed a third value set as an upper limit value of a variation of the first logic state. An over-program verify control function checks that a threshold voltage of the selected memory cell shifted to the second logic state does not exceed a fourth value set as an upper limit thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.