Transmission and phase balance for phase-shifting mask
US6458495B1 · kind B1 · utility
44Cited by
1References
26Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2000 |
| Grant date | Oct 1, 2002 |
| Priority date | — |
| Expiry date | Jul 25, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/30
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention comprises a phase-shifting mask and a process for fabricating such a phase-shifting mask. The phase-shifting mask has trenches with vertical sidewall profiles which are retrograde. The retrograde profiles balance the transmission and phase of the light transmitted through the phase-shifted openings relative to the non-phase-shifted openings. The retrograde profile may be formed from an isotropic plasma etch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.