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US 6,649,268 B1Granted
Optical member made of silica glass, method for manufacturing silica glass, and reduction projection exposure apparatus using the optical member
AssigneeNikon Corporation
InventorsNorio Komine, Seishi Fujiwara, Akiko Yoshida, Hiroki Jinbo, Norihisa Yamaguchi
Life of this patent
Estimating the term…
Abstract
An optical member made of silica glass manufactured by the direct method where a material gas comprising an organosilicon compound is allowed to react in an oxidizing flame, said optical member having a 2×1014 molecules/cm3 or less concentration of formyl radical generated by X-ray irradiation whose dose is 0.01 Mrad or more and 1 Mrad or less.
Claims13
An optical member made of silica glass synthesized by the direct method where a material gas comprising an organosilicon compound is allowed to react in an oxidizing flame,
- said optical member having 1.0×1012 molecules/cm3 or more and 2×1014 molecules/cm3 or less concentration of formyl radical generated by X-ray irradiation whose dose is 0.01 Mrad or more and 1 Mrad or less.
Dependencies are inferred from the claim text.