Programming to minimize cross-temperature threshold voltage widening
US10978145B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 2019 |
| Grant date | Apr 13, 2021 |
| Priority date | — |
| Expiry date | Aug 14, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C2211/5621
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Apparatuses and techniques are provided for programming memory cells while reducing widening of a threshold voltage distribution due to changes in the temperature between the time of programming and the time of a subsequent read operation. One technique is based on a correlation between program speed and temperature coefficient (Tco). A different verify test is used for different memory cells which have a common assigned data state according to the program loop number and the temperature. Another technique is based on sensing the memory cells to measure their subthreshold slope and classifying the memory cells into groups. The sensing can occur as a separate operation before programming or as part of the programming of user data. The subsequent programming of the memory cells involves adjusting the verify test of each memory cell based on its group and the temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.