Vitreous carbon mask substrate for X-ray lithography
First Claim
1. A lithographic mask comprising a vitreous carbon substrate, wherein a surface of the vitreous carbon substrate comprises a microscopically roughened surface and a patterned metal X-ray absorber layer adhering to the microscopically roughened surface.
3 Assignments
0 Petitions
Accused Products
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.
10 Citations
25 Claims
- 1. A lithographic mask comprising a vitreous carbon substrate, wherein a surface of the vitreous carbon substrate comprises a microscopically roughened surface and a patterned metal X-ray absorber layer adhering to the microscopically roughened surface.
- 9. A lithographic mask comprising a vitreous carbon substrate, wherein a surface of the vitreous carbon substrate is etched in a reactive ion oxygen plasma to provide a microscopically roughened surface, and wherein an X-ray resist material is affixed to the microscopically roughened surface.
-
23. A method for preparing a microfabricated device, comprising the steps of.
providing a lithographic mask comprising a vitreous carbon substrate, wherein a surface of the vitreous carbon substrate is etched in a reactive ion oxygen plasma to provide a microscopically roughened surface, and wherein an X-ray resist material is affixed to the microscopically roughened surface; -
exposing the lithographic mask to X-ray radiation through a patterned mask; developing the exposed substrate to remove portions of the resist, thereby providing a plurality of areas open to the microscopically roughened surface of the vitreous carbon substrate; and filling the plurality of areas open to the surface of the vitreous carbon substrate with a metal deposit. - View Dependent Claims (24, 25)
-
Specification