Process for the positioning of a mask relative to a workpiece and device for executing the process
US5881165A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 19, 1996 |
| Grant date | Mar 9, 1999 |
| Priority date | — |
| Expiry date | Sep 19, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/70
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process for positioning a mask relative to a workpiece in which positioning can be done with high accuracy, and which can be advantageously used for step and repeat exposure. An improved device for executing the process of the present invention is also provided. The invention includes a reflection component positioned on a workpiece carrier in a position removed from the workpiece attachment site. The exposure light from an exposure light irradiation device is projected onto the mask and alignment marks provided on the mask are projected onto the reflection component. The alignment mask projection images are detected, their relative positions are stored, and emission of the exposure light terminated. The workpiece carrier, on which a workpiece is placed, is moved into a position in which the mask alignment marks are projected onto the workpiece. Furthermore, nonexposure light is emitted onto the alignment marks of the workpiece, the workpiece alignment marks are detected and their relative positions are determined. Then the workpiece and/or the mask are/is moved such that the mask and workpiece alignment marks come to rest on top of one another.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.