Embedded attenuated phase shift mask and method of making embedded attenuated phase shift mask
US6544696B2 · kind B2 · utility
7Cited by
8References
27Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 30, 2001 |
| Grant date | Apr 8, 2003 |
| Priority date | — |
| Expiry date | Nov 30, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/32
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An embedded attenuated phase shift mask (“EAPSM”) includes an etch stop layer that can be plasma etched in a process that is highly selective to the underlying quartz substrate. Selectivity to the underlying quartz maintains a desired 180 degree phase shift uniformly across the active mask area. Conventional plasma etching techniques can be utilized without damage to the underlying quartz substrate. Alternatively, the etch stop layer comprises a transparent material that can remain intact in the mask structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.