Optimal tungsten through wafer via and process of fabricating same
US7741226B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 6, 2008 |
| Grant date | Jun 22, 2010 |
| Priority date | — |
| Expiry date | Aug 2, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of optimally filling a through via within a through wafer via structure with a conductive metal such as, for example, W is provided. The inventive method includes providing a structure including a substrate having at least one aperture at least partially formed through the substrate. The at least one aperture of the structure has an aspect ratio of at least 20:1 or greater. Next, a refractory metal-containing liner such as, for example, Ti/TiN, is formed on bare sidewalls of the substrate within the at least one aperture. A conductive metal seed layer is then formed on the refractory metal-containing liner. In the invention, the conductive metal seed layer formed is enriched with silicon and has a grain size of about 5 nm or less. Next, a conductive metal nucleation layer is formed on the conductive metal seed layer. The conductive metal nucleation layer is also enriched with silicon and has a grain size of about 20 nm or greater. Next, a conductive metal is formed on the conductive metal nucleation layer. After performing the above processing steps, a backside planarization process is performed to convert the at least one aperture into at least one through via that is now…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.