| 摘要 |
PURPOSE:To prevent the surface deterioration of a photomask raw material, deterioration in line width reproducibility, sensitivity deterioration, etc., and to store the raw material stably for a long period by enclosing the photomask raw material in a gas-impermeable film together with dry inert gas. CONSTITUTION:Tens of photomask raw materials R each formed by laminating a chromium layer 1 and a chromate layer 5 on a glass base 4 are arrayed in a storage case C, which is put in a seal bag S and stored in a pressure reducing chamber 10; and the opening part of the seal bag S is clamped between sealer plates of a heat sealer 13 and the chamber 10 is sealed. Then, the inside of the chamber 10 is reduced in pressure to about 10mm.Hg and dry inert gas (e.g. gaseous nitrogen) is admitted to about 550mm.Hg internal chamber pressure; and the opening part of the bag S is heat-sealed by the sealer 13 and the pressure in the chamber 10 is returned to room temperature, thereby taking the sealed storage case C out of the chamber. |
