Alignment techniques for photolithography utilizing multiple photoresist layers
US6042975A · kind A · utility
17Cited by
1References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 8, 1998 |
| Grant date | Mar 28, 2000 |
| Priority date | — |
| Expiry date | Jul 8, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/0274
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The specification describes a photolithography process using multiple exposures to form z-dimension patterns. Multiple exposures at different thickness levels are made using photomasks aligned with a latent image of alignment marks formed during the first exposure. The latent image is visible to the alignment system of commercial steppers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.