Vitreous carbon mask substrate for X-ray lithography
US7608367B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 2005 |
| Grant date | Oct 27, 2009 |
| Priority date | — |
| Expiry date | Jan 13, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/22
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention is directed to the use of vitreous carbon as a substrate material for providing masks for X-ray lithography. The new substrate also enables a small thickness of the mask absorber used to pattern the resist, and this enables improved mask accuracy. An alternative embodiment comprised the use of vitreous carbon as a LIGA substrate wherein the VC wafer blank is etched in a reactive ion plasma after which an X-ray resist is bonded. This surface treatment provides a surface enabling good adhesion of the X-ray photoresist and subsequent nucleation and adhesion of the electrodeposited metal for LIGA mold-making while the VC substrate practically eliminates secondary radiation effects that lead to delamination of the X-ray resist form the substrate, the loss of isolated resist features, and the formation of a resist layer adjacent to the substrate that is insoluble in the developer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.