Hydroxide-catalysis bonding of optical components used in DUV optical systems
AssigneeCorning Incorporated
InventorsMichael Morgan Dunn, Todd Robert McMichael, Paul Francis Michaloski, Mark Ranney Westcott
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Abstract
A compound lens assembly and method for making a compound lens assembly useful for deep ultraviolet lithography are described. The compound lens assembly includes a first lens component having an optical surface bonded to an optical surface of a second lens component. The bonding at the interface can be achieved using a hydroxide catalysis bonding technique. The compound lens assembly and process for making same solve problems relating to constringence and/or inherent birefringence known for conventional optical elements used in deep ultraviolet lithography or inspection of wafers or reticles in the DUV.
Claims21
A lens assembly with an optical axis, comprising:
- a first optical component, the first optical component having a first optical surface and comprising a metal halide MXn;
- and
- a second optical component having a second optical surface forming an interface with the first optical surface of the first optical component, the interface including a covalent bond between the first optical surface and the second optical surface, the second optical component comprising a metal halide M′X′m or a silica-containing material;
- wherein when the second optical component comprises M′X′m, the covalent bond includes a M-O-M′ bridge;
- and
- wherein when the second optical component comprises a silica-containing material, the covalent bond includes a M-O—Si bridge.
A process for making a lens assembly having an optical axis comprising:
- providing a first optical component having a first optical surface comprising a metal halide MXn;
- providing a second optical component having a second optical surface comprising a metal halide M′X′m or a silica-containing material;
- applying a hydroxide solution to one or both of the first and second optical surfaces;
- forming an interface between the first and second optical surfaces, wherein the hydroxide solution induces hydration of one or both of the first and second optical surfaces and formation of hydroxyl groups on one or both of the first and second optical surfaces;
- and
- dehydrating the interfacing first and second optical surfaces to form a covalent bond between the first and second optical surfaces, wherein when the second optical component comprises M′X′m, the covalent bond includes a M-O-M′ bridge;
- and wherein when the second optical component comprises a silica-containing material, the covalent bond includes a M-O—Si bridge.
A lens assembly, comprising:
- a first optical component composed of silica or MXn, wherein M is a Group 1 or Group 2 metal, X is a halide, and n is 1 if M is a Group 1 metal and n is 2 if M is a Group 2 metal, the first optical component having a convex spherical interfacial surface;
- and
- a second optical component composed of silica or M′X′m, wherein M′ is a Group 1 or Group 2 metal, X′ is a halide, and m is 1 if M′ is a Group 1 metal and m is 2 if M′ is a Group 2 metal, the second optical component having a concave spherical interfacial surface covalently bonded with the convex spherical interfacial surface of the first optical component by an Si—O—Si, M-O—Si or M-O-M′ bridge, wherein M and M′ can be the same or different and X and X′ can be the same or different.
Dependencies are inferred from the claim text.