Method of using a projection aligner for photoetching
US4904570A · kind A · utility
1Cited by
3References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 9, 1989 |
| Grant date | Feb 27, 1990 |
| Priority date | — |
| Expiry date | Feb 9, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/162
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
When a circuit pattern for a semiconductor device is exposed on a substrate with a coating of photoresist by using a projection aligner with positioning pads to properly position the substrate, photoresist is removed from such areas on the substrate that are expected to come in direct contact with the pads. The removing is effected before the substrate is exposed so that accumulation of photoresist on the pads can be prevented and substrates to be exposed subsequently can also be positioned accurately by using the projection aligner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.