Embedded attenuated phase shift mask with tunable transmission
US7312004B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 18, 2004 |
| Grant date | Dec 25, 2007 |
| Priority date | — |
| Expiry date | Mar 28, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/32
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The attenuation and phase shift properties of an embedded attenuated phase shift mask (EAPSM) may be independently selected. After or during plowing of regions of an embedded phase shift layer, exposed regions of a substrate are etched to a predetermined depth. Additional regions of the embedded phase sift layer are then exposed and trimmed to a predetermined thickness for providing the desired amount of attenuation, with the final etched depth of the substrate compensating for the change of relative phase shift caused by trimming of the phase shift layer. A matrix test device having a plurality of cells with different levels of attenuation and/or phase shift may then be fabricated on a single EAPSM blank.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.