Multiple reticle stitching for scanning exposure system
US5437946A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 3, 1994 |
| Grant date | Aug 1, 1995 |
| Priority date | — |
| Expiry date | Mar 3, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/13625
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An improved method for stitching together reticle patterns on a substrate is described. One or more reticles, whose reticle border patterns are to be blended together on the substrate, are provided on an X-Y movable stage in a scanning type exposure system. Each of the reticles has a border pattern which is identical to the border pattern of at least one of the other reticles so that, when the images of these reticles border patterns overlap on the substrate, the overlapping border patterns effectively form a single image on the substrate. To prevent the double exposure of the overlapping border patterns from overexposing the photoresist and to reduce any detrimental effects resulting from misalignment between the overlapping patterns, either a triangular end portion of the scanning source, a filter, or a movable blind is used to partially shade the overlapping border pattern as the UV source is scanned over the border pattern. The graded exposures of the photoresist by the overlapping border patterns combine to fully expose the overlapping border patterns on the substrate. This procedure is continued so as to provide repeated reticle patterns in two dimensions which blend together…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.