Dual damascene process to reduce etch barrier thickness
US6429119B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 1999 |
| Grant date | Aug 6, 2002 |
| Priority date | — |
| Expiry date | Sep 27, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2221/1063
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Using this special dual damascene process, interconnect conducting lines and via contacts are formed which have low parasitic capacitance (low RC time constants). The invention incorporates the use of thin etch stop or etch barrier layers. The key process steps of this invention are a special partial via hole etch and a special via hole liner. The Prior Art dual damascene processes are generally composed of a thick via etch stop layer to avoid damaging underlying Cu during via patterning, as well as, a thick trench etch stop layer to avoid via hole facet during trench patterning. Thick etch stop layers are undesirably due to high dielectric constant values compared with silicon oxide, the intermetal dielectric (IMD). Therefore, the thickness of stop-layer should be reduced to minimize the circuit (RC) time constant delay. In general, there are two main approaches for dual damascene etching. One of the main approaches use self-aligned dual damascene (SADD) etching which requires a thick trench etching stop-layer thickness. The other approach use counter-bore method which requires a thick via etching stop-layer thickness. This invention describes a novel dual damascene process which …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.