Use of polarization and composite illumination source for advanced optical lithography
US8612904B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 2012 |
| Grant date | Dec 17, 2013 |
| Priority date | — |
| Expiry date | Nov 21, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70566
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Embodiments of the invention provide approaches for optimizing illumination and polarization for advanced optical lithography. Specifically, an illumination pupil plane of an illumination source is bisected into a plurality of elements. Preferred elements of the illumination pupil plane are selected for a set of integrated circuit (IC) design features. An imaging performance of the set of IC design features for the preferred elements is evaluated at different polarization states to determine an optimal illumination and polarization condition for each IC design feature. Imaging performance of the combined IC design features, evaluated at various optimal illumination and polarization outcomes synthesized at different intensity ratios, is reviewed against a set of design tolerance requirements to finalize optical illumination and polarization conditions for the entire IC design. An optimal illumination and polarization solution is identified for an off-contact pattern with a plurality of sub-resolution assisted features connecting line-line-end portions of main mask features.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.