Method of depositing a copper seed layer which promotes improved feature surface coverage
US6500762B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 24, 2002 |
| Grant date | Dec 31, 2002 |
| Priority date | — |
| Expiry date | Jan 24, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
We have discovered a method of improving step coverage of a copper seed layer deposited over a semiconductor feature surface which is particularly useful for small size features having a high aspect ratio. We have demonstrated that it is possible to increase the copper seed layer coverage simultaneously at the bottom of a high aspect ratio contact via and on the walls of the via by increasing the percentage of the depositing copper species which are ions. The percentage of species ionization which is necessary to obtain sufficient step coverage for the copper seed layer is a function of the aspect ratio of the feature. An increase in the percentage of copper species which are ionized can be achieved using techniques known in the art, including but not limited to applicants' preferred technique, an inductively coupled RF ion metal plasma.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.