Method of reducing trapped holes induced by erase operations in the tunnel oxide of flash memory cells
US6426898B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 5, 2001 |
| Grant date | Jul 30, 2002 |
| Priority date | — |
| Expiry date | Mar 5, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/16
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method of erasing memory cells in a flash memory device that recombines holes trapped in the tunnel oxide (after an erase operation) with electrons passing through the tunnel oxide is disclosed. The method uses an erase operation that over-erases all memory cells undergoing the erase operation. A cell healing operation is performed on the over-erased cells. The healing operation causes electrons to pass through the tunnel oxide and recombine with trapped holes. The recombination substantially reduces the trapped holes within the tunnel oxide without reducing the speed of the erase operation. Moreover, by reducing trapped holes, charge retention, overall performance and endurance of the flash memory cells are substantially increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.