Controlled hot-electron writing method for non-volatile memory cells
US6172908A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 8, 1998 |
| Grant date | Jan 9, 2001 |
| Priority date | — |
| Expiry date | Oct 8, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/12
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In order to optimize writing of the cell, the latter is written in a condition of equilibrium between an injection current I.sub.g and the displacement current C.sub.pp V.sub.sl. In this way, during writing, the voltage of the floating gate region V.sub.fl remains constant, as does the drain current and the rise in the threshold voltage. In particular, both for programming and for soft-writing after erasure, the substrate of the cell is biased at a negative voltage V.sub.sb with respect to the source region, and the control gate region of the cell receives a ramp voltage V.sub.cg with a selected predetermined inclination V.sub.sl satisfying an equilibrium condition V.sub.sl <I.sub.g,sat /C.sub.pp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.