Zone plate alignment marks
US4037969A · kind A · utility
76Cited by
4References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 2, 1976 |
| Grant date | Jul 26, 1977 |
| Priority date | — |
| Expiry date | Apr 2, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Certain classes of patterns, for example so-called zone plates, are utilized as alignment marks in the fabrication of integrated circuits. Such a plate, which functions as a lens, provides a high-brightness image that is relatively insensitive to any degradation of the pattern.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.