Process for positioning of a mask relative to another mask, or masks relative to a workpiece and device for executing the process
US5940528A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1996 |
| Grant date | Aug 17, 1999 |
| Priority date | — |
| Expiry date | Jul 29, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7084
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process for positioning, in which a dummy is not used, in which multichromatic light can be used as the light source for purposes of alignment, and in which aberration correction is unnecessary, and a device for executing the process is achieved according to the invention by executing projection onto a first mask by projection lenses in which at least the workpiece facing sides of the lenses are telocentric. In a state in which a workpiece is remote, light with exposure wavelengths is emitted from a light irradiation part onto a second mask. The first mask (or second mask) is moved such that the projected images of the alignment marks of the second mask and the alignment marks of the first mask come to lie on top of one another. Furthermore, the irradiation light is branched off by beam splitters and positions of the alignment marks of the second mask are stored. Next, emission of the light with exposure wavelengths is stopped, a workpiece is inserted into a predetermined position, from another light irradiation part light multichrome with nonexposure wavelengths is emitted, positions of the alignment marks of the workpiece are determined and the workpiece is moved to bring these…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.