Method of operating a single transistor non-volatile electrically alterable semiconductor memory device
US5572054A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 1995 |
| Grant date | Nov 5, 1996 |
| Priority date | — |
| Expiry date | Sep 1, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/035
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A single transistor electrically programmable and erasable memory cell is disclosed. The single transistor has a source, a drain with a channel region therebetween, defined on a substrate. A first insulating layer is over the source, channel and drain regions. A floating gate is positioned on top of the first insulating layer over a portion of the channel region and over a portion of the source region. A second insulating layer has a top wall which is over the floating gate, and a side wall which is adjacent thereto. A control gate has a first portion which is over the first insulating layer and immediately adjacent to the side wall of the second insulating layer. The control gate has a second portion which is over the top wall of the second insulating layer and is over the floating gate. Erasure of the cell is accomplished by the mechanism of Fowler-Nordheim tunneling from the floating gate through the second insulating layer to the control gate. Programming is accomplished by electrons from the drain migrating through the channel region underneath the control gate and then by abrupt potential drop injecting through the first insulating layer into the floating gate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.