Method of manufacturing and application of dual alignment photomask
US6171732A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 4, 1999 |
| Grant date | Jan 9, 2001 |
| Priority date | — |
| Expiry date | May 4, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70291
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of forming a dual alignment photomask. The method includes the steps of depositing a light-blocking layer over a glass plate, and then patterning the light-blocking layer. Next, a switchable mask layer is deposited over the light-blocking layer and the glass plate, after which the switchable mask layer is patterned. Finally, a protective layer is formed over the switchable mask layer, the light-blocking layer and the glass plate. The switchable mask layer can be changed from a light-passing state to a light-blocking state by simply changing the surrounding temperature. Therefore, through proper setting the temperature, the same photomask can be used to form trenches and vias of dual damascene structures. Thus, some mask-making cost can be saved and errors due to mask misalignment can be avoided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.