Measuring method and apparatus for meausring the positional relationship of first and second gratings
US5333050A · kind A · utility
48Cited by
4References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 26, 1991 |
| Grant date | Jul 26, 1994 |
| Priority date | — |
| Expiry date | Mar 26, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7049
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Disclosed is a method and apparatus for measuring a relative positional deviation between a first pattern and a second pattern, printed on an article such as a semiconductor wafer at different moments, the measurement being based on detection of interference of diffraction lights from at least one of the first and second printed patterns.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.