Advanced BEOL interconnect structures with low-k PE CVD cap layer and method thereof
US6737747B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 15, 2002 |
| Grant date | May 18, 2004 |
| Priority date | — |
| Expiry date | Jan 15, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An advanced back-end-of-line (BEOL) metallization structure is disclosed. The structure includes a diffusion barrier or cap layer having a low dielectric constant (low-k), where the cap layer is formed of silicon nitride by a plasma-enhanced chemical vapor deposition (PE CVD) process. The metallization structure also includes an inter-layer dielectric (ILD) formed of a carbon-containing dielectric material having a dielectric constant of less than about 4, and a continuous hardmask layer overlying the ILD which is preferably formed of silicon nitride or silicon carbide. A method for forming the BEOL metallization structure is also disclosed. The method includes a pre-clean or pre-activation step to improve the adhesion of the cap layer to the underlying copper conductors. The pre-clean or pre-activation step comprises exposing the copper surface to a reducing plasma including hydrogen, ammonia, nitrogen and/or noble gases.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.