Program and erase in a thin film storage non-volatile memory
US6791883B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 2002 |
| Grant date | Sep 14, 2004 |
| Priority date | — |
| Expiry date | Sep 17, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/0466
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A non-volatile memory having a thin film dielectric storage element is programmed by hot carrier injection (HCI) and erased by tunneling. The typical structure for the memory cells for this type of memory is silicon, oxide, nitride, oxide, and silicon (SONOS). The hot carrier injection provides relatively fast programming for SONOS, while the tunneling provides for erase that avoids the difficulties with the hot hole erase (HHE) type erase that generally accompanies hot carrier injection for programming. HHE is significantly more damaging to dielectrics leading to reliability issues. HHE also has a relatively narrow area of erasure that may not perfectly match the pattern for the HCI programming leaving an incomplete erasure. The tunnel erase effectively covers the entire area so there is no concern about incomplete erase. Although tunnel erase is slower than HHE, erase time is generally less critical in a system operation than is programming time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.