Alignment strategy for asymmetrical alignment marks
US6074950A · kind A · utility
11Cited by
1References
5Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 22, 1999 |
| Grant date | Jun 13, 2000 |
| Priority date | — |
| Expiry date | Jan 22, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/68
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An alignment strategy for asymmetrical alignment marks in a wafer, in which the positions of the a symmetrical alignment marks are determined twice. A first set of positions is detected after a chemical-mechanical polishing step. A second set of positions is detected after a rotation in which the wafer is rotated by 180.degree. in the plane of the surface of the wafer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.