Lithographic systems and methods with extended depth of focus
US7088419B2 · kind B2 · utility
14Cited by
21References
15Claims
0Family size
Assignee
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Key dates
| Filing date | Jun 1, 2004 |
| Grant date | Aug 8, 2006 |
| Priority date | — |
| Expiry date | Oct 7, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70308
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical lithography system that has extended depth of focus exposes a photoresist coating on a wafer, and includes an illumination sub-system, a reticle, and an imaging lens that has a pupil plane function to form an aerial image of the reticle proximate to the photoresist. The pupil plane function provides the extended depth of focus such that the system may be manufactured or used with relaxed tolerance, reduced cost and/or increased throughput. The system may be used to form precise vias within integrated circuits even in the presence of misfocus or misalignment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.