Non-volatile semiconductor memory having split-gate memory cells mirrored in a virtual ground configuration
US6717846B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 2000 |
| Grant date | Apr 6, 2004 |
| Priority date | — |
| Expiry date | Dec 22, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/0425
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In this invention a process for a flash memory cell and an architecture for using the flash memory cell is disclosed to provide a nonvolatile memory having a high storage density. Adjacent columns of cells share the same source and the source line connecting these sources runs vertically in the memory layout, connecting to the sources of adjacent columns memory cells. Bit lines connect to drains of cells in adjacent columns and are laid out vertically, alternating with source lines in an every other column scheme. Wordlines made of a second layer of polysilicon form control gates of the flash memory cells and are continuous over the full width of a memory partition. Programming is done in a vertical page using hot electrons to inject charge onto the floating gates. The cells are crased using Fowler-Nordheim tunneling of electrons from the floating gate to the control gate by way of inter polysilicon oxide formed on the walls of the floating gates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.