Off-axis pupil aperture and method for making the same
US6426131B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 1999 |
| Grant date | Jul 30, 2002 |
| Priority date | — |
| Expiry date | Jul 21, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24273
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Disclosed is a pupil aperture, and method for making the pupil aperture for use in a photolithography scanner system. The pupil aperture includes a plate having a set of pole apertures that are radially offset from a reference center point of the plate. The plate further includes a horizontal reference line that intersects the reference center point. The horizontal reference line is used to define a target angle that is between about 15 degrees and about 35 degrees from the horizontal reference line. The target angle defines an off-axis location for each of the set of pole apertures. In a specific aspect of this invention, a set ranging between 3 to 9 pole apertures can be defined in the plate, and their offset from the center point can be selected to be between about 0.3 inches and about 0.9 inches.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.