Etch stop for copper damascene process
US5693563A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 15, 1996 |
| Grant date | Dec 2, 1997 |
| Priority date | — |
| Expiry date | Jul 15, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention describes the application of copper damascene connectors to a double level metal process. A dual damascene copper connector whose upper surface is coplanar with the upper surface of the insulating layer in which it is embedded is described. Out-diffusion of copper from the connector is prevented by at least two barrier layers. One or two barrier layers are located at the interface between the connector and the insulating layer while another barrier layer comprises conductive material and covers the upper surface of the connector. When a second damascene connector is formed above the first connector the conductive barrier layer facilitates good contact between the two connectors. It also acts as an etch stop layer during the formation of the second connector. A process for manufacturing this structure is also described. It involves over-filling a trench in the surface of the insulator with copper and then removing the excess by chem.-mech. polishing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.