Apparatus for and method of projecting a mask pattern on a substrate
US5144363A · kind A · utility
74Cited by
4References
71Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 24, 1991 |
| Grant date | Sep 1, 1992 |
| Priority date | — |
| Expiry date | Jan 24, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7049
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection apparatus is described having a reference plate with a set of grating marks in X and Y directions for aligning with an exposure mask having similar marks, and having four detectors for each mark, and having a lens system for projecting only the relevant mark on the relevant detector. A method of projecting is also described in which the detection signals are simultaneously processed with other signals to result in a control signal to adjust image quality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.