Apparatus for projecting a mask pattern on a substrate
US5481362A · kind A · utility
56Cited by
12References
28Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 6, 1993 |
| Grant date | Jan 2, 1996 |
| Priority date | — |
| Expiry date | May 6, 2013 |
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 mask alignment mark (M.sub.1, M.sub.2) with respect to a substrate alignment mark (P.sub.1, P.sub.2). Means (WE.sub.1, WE.sub.2) preventing phase differences due to reflections at the mask plate (MA) from occurring within the alignment beam portions received by a detection system (13, 13') are arranged in the path of selected alignment beam portions (b.sub.1, b.sub.1 ').
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.