Method for reducing reflectivity of a metal layer
US5888908A · kind A · utility
1Cited by
19References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1995 |
| Grant date | Mar 30, 1999 |
| Priority date | — |
| Expiry date | Apr 28, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/0276
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method is provided for reducing the reflectivity of a metal layer prior to photolithography. A thin buffer layer, such as oxide, can be deposited over the metal layer. A short plasma etch is performed in order to roughen, but not completely remove, the thin oxide layer. This roughened layer significantly reduces the reflectivity of the underlying metal layer. As an alternative, the brief plasma etch can be applied directly to the metal layer, which results in a significant roughening of its upper surface. This also reduces the reflectivity of the metal layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.