| 摘要 |
PROBLEM TO BE SOLVED: To provide an article related to a silica glass member for optical use having all properties required for its suitability in a semiconductor aligner, especially one using ultraviolet radiation such as an excimer laser and its manufacturing process, specifically a synthetic silica glass member for optical use having a high homogeneity, a low birefringence and a high resistance to UV irradiation and its manufacturing process. SOLUTION: The manufacturing process comprises (a) a step wherein a transparent silica glass body is obtained by hydrolyzing a volatile silica compound with oxyhydrogen flame, depositing the resulting particulate silica on a heat-resistant substrate to prepare a porous preform and heating this to≥1,723 K, (b) a step wherein the transparent silica glass body is heated to at least its softening point and deformed by an external force to remove striae, (c) a step wherein the silica glass body from which the striae is removed is temporarily kept at a temperature equal to or above its annealing point and subsequently annealed to set its fictive temperature to≤1,273 K, and (d) a step wherein the silica glass whose fictive temperature is set to≤1,273 K is heat-treated at≤773 K in a hydrogen gas-containing atmosphere under 0.0098-0.98 MPa to obtain the silica glass body containing hydrogen molecules. COPYRIGHT: (C)2004,JPO
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