Etch stop layer for dual damascene process
US6291334A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 19, 1997 |
| Grant date | Sep 18, 2001 |
| Priority date | — |
| Expiry date | Dec 19, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76829
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention provides a carbon based etch stop, such as a diamond like amorphous carbon, having a low dielectric constant and a method of forming a dual damascene structure. The low k etch stop is preferably deposited between two dielectric layers and patterned to define the underlying interlevel contacts/vias. The second or upper dielectric layer is formed over the etch stop and patterned to define the intralevel interconnects. The entire dual damascene structure is then etched in a single selective etch process which first etches the patterned interconnects, then etches the contact/vias past the patterned etch stop. The etch stop has a low dielectric constant relative to a conventional SiN etch stop, which minimizes the capacitive coupling between adjacent interconnect lines. The dual damascene structure is then filled with a suitable conductive material such as aluminum or copper and planarized using chemical mechanical polishing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.