Two transistor flash EEprom cell and method of operating same
US5862082A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1998 |
| Grant date | Jan 19, 1999 |
| Priority date | — |
| Expiry date | Apr 16, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/0433
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A flash electrically erasable programmable read only memory (EEPROM) cell fabricated in a semiconductor substrate. A first well region having a first conductivity type is located in the semiconductor substrate. A second well region having a second conductivity type, opposite the first conductivity type, is located in the first well region. A non-volatile memory transistor and an independently controllable access transistor are fabricated in the second well region. The non-volatile memory transistor and the access transistor are connected in series, such that the source of the access transistor is coupled to the drain of the non-volatile memory transistor. The first well region, the second well region, the non-volatile memory transistor and the access transistor are biased such that electrons are transferred from the first well region to a floating gate of the non-volatile memory transistor by Fowler-Nordheim tunneling during an erase mode, and electrons are transferred from the floating gate of the non-volatile memory transistor through the access transistor by Fowler-Nordheim tunneling during a program mode. None of the biasing voltages exceed 12 Volts, thereby enabling the flash …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.