Apparatus for projecting a mask pattern on a substrate
US5100237A · kind A · utility
76Cited by
2References
34Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 25, 1990 |
| Grant date | Mar 31, 1992 |
| Priority date | — |
| Expiry date | May 25, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7049
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An apparatus for projecting a mask pattern (MA) on a substrate (W) by means of a projection lens system (PL) is described, which apparatus comprises a device for aligning a substrate alignment mark (P.sub.1 ; P.sub.2) with respect to a mask alignment mark (M.sub.1 ; M.sub.2), the projection lens system (PL) forming part of the alignment device. A correction element (25) is arranged in this system (PL) to compensate for the fact that this system (PL) is not optimized for the wavelength of the alignment beam (b).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.