In-situ balancing for phase-shifting mask
US6660649B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2002 |
| Grant date | Dec 9, 2003 |
| Priority date | — |
| Expiry date | Aug 29, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/942
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention describes a method of forming a mask comprising: providing a substrate, the substrate having a first thickness; forming a balancing layer over the substrate, the balancing layer having a second thickness; forming an absorber layer over the balancing layer, the absorber layer having a first region separated from a second region by a third region; removing the absorber layer in the first region and the second region; removing the balancing layer in the second region; and reducing the substrate in the second region to a third thickness. The present invention also describes a mask comprising: an absorber layer, the absorber layer having a first opening and a second opening, the first opening uncovering a balancing layer disposed over a substrate having a first thickness, and the second opening uncovering the substrate having a second thickness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.