Projection lithography photomasks and methods of making
AssigneeCorning Incorporated
InventorsGeorge Edward Berkey, Lisa Anne Moore, Michelle Diane Pierson
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Abstract
The present invention is a method of making a lithography photomask and photomask blank. The method of making the lithography photomask and photomask blank includes providing a silicon oxyfluoride glass tube having an OH content less than 50 ppm. The method further includes cutting the silicon oxyfluoride glass tube, flattening the silicon oxyfluoride glass tube, and forming the flattened cut silicon oxyfluoride glass tube into a photomask blank having a planar surface. The present invention includes a glass lithography mask preform. The glass lithography mask preform is a longitudinal silicon oxyfluoride glass tube that has an OH content ≦10 ppm, a F wt. % concentration ≧0.5 wt. %.
Claims59
A method of making a lithography photomask blank, comprising the steps of:
- providing a silicon oxyfluoride glass tube having an OH content less than 50 ppm,
- cutting said silicon oxyfluoride glass tube,
- flattening the silicon oxyfluoride glass tube, and
- forming said flattened cut silicon oxyfluoride glass tube into a photomask blank having a planar surface.
A lithography photomask blank comprising a flat planar silicon oxyfluoride glass member having a top planar surface and a bottom planar surface, said planar silicon oxyfluoride glass member having an OH content ≦10 ppm, a F wt. % concentration ≧0.5 wt. %, said silicon oxyfluoride glass having less than 1×1017 H2 molecules/cm3 and parallel layers of striae wherein said parallel layers of striae are parallel to said top planar surface.
A method of making a mask comprising the steps of:
- providing a glass tube mask preform having an inside radius IR, a thickness T, a length L, a longitudinal center tube axis CA, and said glass tube mask preform includes concentric layers of striae centered about said center axis CA, flattening said glass tube mask preform into a flat planar glass mask having a top planar surface and a bottom planar surface, wherein said flat planar glass mask has parallel layers of striae that are parallel to said top planar surface and said bottom planar surface.
A method of making a photomask blank, said method comprises:
- providing a silicon oxyfluoride glass tube;
- heating said glass tube;
- evacuating said heated glass tube to collapse said glass tube into a flattened collapsed tube;
- forming said flattened collapsed tube into a photomask blank.
Dependencies are inferred from the claim text.