Simultaneous, two-sided projection lithography system
US5923403A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 8, 1997 |
| Grant date | Jul 13, 1999 |
| Priority date | — |
| Expiry date | Jul 8, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70475
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
This projection imaging system is capable of simultaneously exposing both the upper and lower sides of a substrate while providing high-resolution, a large exposure area, and high exposure throughput. The system comprises: PA1 (a) a single stage, holding a substrate, upper mask, and lower mask in fixed juxtaposition, that is capable of scanning in one direction, and when not scanning in that direction, capable of moving laterally in a dimension perpendicular to the scan direction so as to position itself for another scan parallel to the original scan; PA1 (b) an illumination system having an effective source plane of a predetermined shape, capable of simultaneously illuminating on both the upper and lower masks a region of the above predetermined shape; PA1 (c) an upper and lower projection system having an object to image magnification ratio of unity, each having a reverser assembly to render both the upper and lower images on the substrate in the same orientation as the mask pattern: PA1 (d) a fixed offset, lateral to the optical axis, is provided by each reverser assembly, between each mask and the substrate, the offsets for the two masks being equal and in opposite directions f…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.