Photographic mask and method for making same
US10331026B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 2016 |
| Grant date | Jun 25, 2019 |
| Priority date | — |
| Expiry date | Apr 7, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2201/003
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A photographic mask is provided in the present disclosure. The photographic mask includes a silicon-on-insulator (SOI) base and a stepped opening formed in the SOI base. The SOI base includes a silicon substrate, a median layer and a silicon layer, the median layer is arranged between the insulator substrate and the insulator layer. The stepped opening includes a first opening portion and a second opening portion, the first opening portion penetrates through the silicon layer and has a first opening area; the second opening portion at least penetrates through the silicon substrate and is aligned with the first opening portion. The second opening portion has a second opening area greater than the first opening area of the first opening portion. The present disclosure further provides a method for making a photographic mask.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.