Pattern forming method and photomasks used therefor
US5316878A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 1992 |
| Grant date | May 31, 1994 |
| Priority date | — |
| Expiry date | Jun 4, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70466
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a photoresist pattern formation by exposure using first and second photomasks, the first photomask has a transparent part, a rectangular opaque part having a first pair of sides and a second pair of sides, and a phase shifter, having a first edge crossing one of the first pair of sides, so that a part of the first edge is in the transparent part, and the second photomask has a transparent part, a rectangular opaque part corresponding to the rectangular opaque part of the first photomask, and a stripe-shaped opaque part corresponding to the first part of the first edge of the phase shifter. The rectangular opaque part of the first photomask is expanded in the direction of the first pair of sides, while the rectangular opaque part of the second photomask is expanded in the direction the second pair of sides. The amount of expansion is preferably not smaller than a misalignment tolerance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.