Microlithographic device, microlithographic assist features, system for forming contacts and other structures, and method of determining mask patterns
US6803155B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 2001 |
| Grant date | Oct 12, 2004 |
| Priority date | — |
| Expiry date | Aug 7, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/29
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of formulating and fabricating a mask pattern and resulting mask for forming isolated or closely spaced contact holes in an integrated circuit. The mask has a transparent mask substrate and patterned regions of attenuating phase shift material and opaque, partially transmissive or transparent material arranged to reduce the effect of side lobes and improve depth of focus. The rims, frames and outrigger patterns for the attenuating phase shift material and opaque, partially transmissive or transparent material are determined according to calculations performed on a processor with imaging software for various optical conditions and exposed feature criteria.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.