Reflective mask and method of making same
US8877409B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 2012 |
| Grant date | Nov 4, 2014 |
| Priority date | — |
| Expiry date | Sep 14, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/0337
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A reflective mask is described. The mask includes a low thermal expansion material (LTEM) substrate, a conductive layer deposited on a first surface of the LTEM substrate, a stack of reflective multilayers (ML) deposited on a second surface of the LTEM substrate, a capping layer deposited on the stack of reflective ML, a first absorption layer deposited on the first capping layer, a main pattern, and a border ditch. The border ditch reaches to the capping layer, a second absorption layer deposited inside the border ditch, and the second absorption layer contacts the capping layer. In some instances, the border ditch crosses the capping layer and partially enters the reflective multilayer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.