Multiple exposure process for formation of dense rectangular arrays
US6511791B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Apr 28, 2000 |
| Grant date | Jan 28, 2003 |
| Priority date | — |
| Expiry date | Apr 28, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/203
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for exposing a workpiece in a dual exposure step-and-repeat process starts by forming a design for a reticle mask. Deconstruct the design for the reticle mask by removing a set(s) of the features that are juxtaposed to form hollow polygonally-shaped clusters with a gap in the center. Form unexposed resist on the workpiece. Load the workpiece and the reticle mask into the stepper. Expose the workpiece through the reticle mask. Reposition the workpiece by a nanostep. Then expose the workpiece through the reticle mask after the repositioning. Test whether the plural exposure process is finished. If the result of the test is NO the process loops back to repeat some of the above steps. Otherwise the process has been completed. An overlay mark is produced by plural exposures of a single mark. A dead zone is provided surrounding an array region in which printing occurs subsequent to exposure in an original exposure. Alternatively, the workpiece can be fully exposed first by stepping a series of full steps, then going back to the starting position, making a nanostep to reset the starting position and re-exposing from the reset starting position in the same way with full steps from…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.