Process for selectively etching dielectric layers
US6905968B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 2001 |
| Grant date | Jun 14, 2005 |
| Priority date | — |
| Expiry date | May 22, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/02274
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method is provided for etching a dielectric structure. The dielectric structure comprises: (a) a layer of undoped silicon oxide or F-doped silicon oxide; and (b) a layer of C,H-doped silicon oxide. The dielectric structure is etched in a plasma-etching step, which plasma-etching step is conducted using a plasma source gas that comprises nitrogen atoms and fluorine atoms. As one example, the plasma source gas can comprise a gaseous species that comprises one or more nitrogen atoms and one or more fluorine atoms (e.g., NF3). As another example, the plasma source gas can comprise (a) a gaseous species that comprises one or more nitrogen atoms (e.g., N2) and (b) a gaseous species that comprises one or more fluorine atoms (e.g., a fluorocarbon gas such as CF4). In this etching step, the layer of C,H-doped silicon oxide is preferentially etched relative to the layer of undoped silicon oxide or F-doped silicon oxide. The method of the present invention is applicable, for example, to dual damascene structures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.