Method for fabrication of a high capacitance interpoly dielectric
US6709990B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 2002 |
| Grant date | Mar 23, 2004 |
| Priority date | — |
| Expiry date | Nov 1, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/02271
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for fabricating a silicon dioxide/silicon nitride/silicon dioxide (ONO) stacked composite having a thin silicon nitride layer for providing a high capacitance interpoly dielectric structure. In the formation of the ONO composite, a bottom silicon dioxide layer is formed on a substrate such as polysilicon. A silicon nitride layer is formed on the silicon dioxide layer and is thinned by oxidation. The oxidation of the silicon nitride film consumes some of the silicon nitride by a reaction that produces a silicon dioxide layer. This silicon dioxide layer is removed with a hydrofluoric acid dilution. The silicon nitride layer is again thinned by re-oxidization as a top silicon dioxide layer is formed on the silicon nitride layer. A second layer of polysilicon is deposited over the silicon nitride, forming an interpoly dielectric.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.