System and method for preventing electrochemical erosion by depositing a protective film
US6451698B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1999 |
| Grant date | Sep 17, 2002 |
| Priority date | — |
| Expiry date | Apr 7, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/7684
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for making reliable interconnect structures on a semiconductor substrate having a first dielectric layer is disclosed. The method includes depositing a glue layer of TiN followed by tungsten chemical vapor deposition after the contact or via is defined in the dielectric. Then, tungsten etchback or Chemical Mechanical Polishing (CMP) is performed to remove the tungsten and TiN over the dielectric surface with slight dishing of the tungsten within the plug. Next, a blanket deposition of Copper by electrochemical deposition is performed and Copper CMP is used to remove the copper from the dielectric surface while maintaining a coating of copper over the tungsten in the plug. Then, metal stack deposition, patterning and metal etching is performed and a barrier layer of silicon nitride is presented to minimize the copper diffusion. Finally, a deposition of an Interlevel Dielectric (ILD) is deposited. The deposition of a protective material such as copper above the tungsten in the plug blocks the dissolution pathway of tungsten in the highly alkaline post metal etch strip solvent. Copper is used as an example due to its favorable characteristic of being deposited and polished co…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.