Deposition of doped copper seed layers having improved reliability
US8017523B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 2008 |
| Grant date | Sep 13, 2011 |
| Priority date | — |
| Expiry date | May 16, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Improved methods of depositing copper seed layers in copper interconnect structure fabrication processes are provided. Also provided are the resulting structures, which have improved electromigration performance and reduced line resistance. According to various embodiments, the methods involve depositing a copper seed bilayer on a barrier layer in a recessed feature on a partially fabricated semiconductor substrate. The bilayer has a copper alloy seed layer and a pure copper seed layer, with the pure copper seed layer is deposited on the copper alloy seed layer. The copper seed bilayers have reduced line resistance increase and better electromigration performance than conventional doped copper seed layers. Precise line resistance control is achieved by tuning the bilayer thickness to meet the desired electromigration performance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.