Phase-shifted opaquing ring
US5446521A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 1994 |
| Grant date | Aug 29, 1995 |
| Priority date | — |
| Expiry date | Oct 7, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70433
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An attenuated phase-shifted reticle is disclosed. The reticle comprises a device region and a scribeline region. The scribeline region further comprises metrology cells, which contain features to be patterned for the purpose of measurement, etc. Other portions of the scribeline region comprise a sub-resolution pattern of, for example, lines and spaces 180.degree. out of phase. Since the pattern is sub-resolution, it will not print. Since the pattern comprises features 180.degree. out of phase, the intensity of radiation underneath the pattern is significantly reduced. Therefore, in a lithography method incorporating multiple exposures of the scribeline region, the metrology cells are not overexposed by the overlapping exposures in the stepping system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.