Method for high precision programming nonvolatile memory cells, with optimized programming speed
US6392931B1 · kind B1 · utility
62Cited by
5References
21Claims
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Key dates
| Filing date | Nov 24, 1999 |
| Grant date | May 21, 2002 |
| Priority date | — |
| Expiry date | Nov 24, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C27/005
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A programming method comprises the steps of applying a ramp voltage having a first slope to the gate terminal of a selected memory cell to rapidly bring the threshold voltage of the selected cell to an intermediate value; then applying a ramp voltage having a second slope lower than the first, to end programming to the desired final threshold value with high precision. Thereby, when a high threshold value is to be programmed, programming time is reduced; on the other hand, if a low threshold value is to be programmed, the slower ramp voltage is applied right from the start, to prevent possible overprogramming of the cell.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.