| 摘要 |
PURPOSE:To obtain an alkali-free glass for photoetching mask having improved meltability, by defining the composition of a glass to contain specific amounts of SiO2, Al2O3, PbO, CaO, MgO, ZnO, ZrO2, F2, As2O3 and Sb2O3. CONSTITUTION:A raw material prepared by mixing the components to give the following composition: 55-65mol% SiO2, 7-11mol% Al2O3, 1-11mol% PbO, 7-20mol% CaO, 3-13mol% MgO, 3-13mol% ZnO, 0-3mol% ZrO2, 0-3mol% F2, 0-5mol% As2O3 and 0-5mol% Sb2O3. The raw material is molten at 1,400- 1,500 deg.C, and annealed at a cooling rate of about 10 deg.C/hr. The resultant glass has a high specific resistance due to no alkali and is characterized by the property of scarcely deteriorating a Nesa coating. Furthermore, the moldability is good with a slight solarization with electron rays because of the PbO contained therein. |
