Method of fabricating self-aligned metal barriers by atomic layer deposition on the copper layer
US6905964B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 2003 |
| Grant date | Jun 14, 2005 |
| Priority date | — |
| Expiry date | Jan 9, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/28562
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An improved and new process for fabricating self-aligned metal barriers by atomic layer deposition, ALD, capable of producing extremely thin, uniform, and conformal metal barrier films, selectively depositing on copper, not on silicon dioxide interlevel dielectric, in multi-layer dual damascene trench/via processing. Silicon nitride is presently used as a insulating copper barrier. However, silicon nitride has a relatively high dielectric constraint, which deteriorates ICs with increased RC delay. Copper metal barriers of niobium and tantalum have been deposited by atomic layer deposition on copper. With high deposition selectivity, the barrier metal is only deposited over copper, not on silicon dioxide, which eliminates the need of an insulating barrier of silicon nitride.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.