Electroless CU deposition on a barrier layer by CU contact displacement for ULSI applications
US5891513A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jan 16, 1996 |
| Grant date | Apr 6, 1999 |
| Priority date | — |
| Expiry date | Jan 16, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S977/892
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method of utilizing electroless copper deposition to form interconnects on a semiconductor wafer. Once a via or a trench is formed in a dielectric layer, a titanium nitride (TiN) or tantalum (Ta) barrier layer is blanket deposited. Then, a contact displacement technique is used to form a thin activation seed layer of copper on the barrier layer. An electroless deposition technique is then used to auto-catalytically deposit copper on the activated barrier layer. The electroless copper deposition continues until the via/trench is filled. Subsequently, the surface is polished by an application of chemical-mechanical polishing (CMP) to remove excess copper and barrier material from the surface, so that the only copper and barrier material remaining are in the via/trench openings. Then an overlying silicon nitride (SiN) layer is formed above the exposed copper in order to form a dielectric barrier layer. The copper interconnect is fully encapsulated from the adjacent material by the TiN (or Ta) and the SiN layers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.