摘要 |
According to one aspect of the invention, there is provided glass for a photomask consisting, in weight percent, of 45 to 62% SiO2, 3 to 15% B2O3, 12 to 25% Al2O3, 5 to 15% MgO, 0 to 5% CaO, 0 to 5% SrO, 0 to 5% BaO, 0 to 5% ZnO, 0.5 to 5% PbO, 0 to 20% La2O3+Gd2O3+Y2O3, 0 to 1.5% Na2O, 0 to 1.5% K2O, 0 to 0.5% As2O3 and 0 to 6% Sb2O3. This glass is easy to melt and homogenize and has good resistivity to phase separation and excellent heat resisting and refractory properties, chemical durability, ultraviolet transmittance and metal vapor deposition property. According to another aspect of the invention, there is provided glass for a photomask consisting, in weight %, 45 to 60% SiO2, 0.5 to 12% B2O3, 10 to 22% Al2O3, 5 to 17% MgO, 0 to 5% CaO, 0 to 8% SrO, 1.5 to 15% BaO, 1.5 to 17% ZnO, 0.5 to 10% PbO, the total content of ZnO and PbO being at least 6%, 0 to 7% Ta2O5+Nb2O5+La2O3+Gd2O3+Y2O3+Bi2O3+WO3, 0 to 5% ZrO2+TiO2, 0 to 2.5% Na2O+K2O+Li2O, 0 to 0.5% As2O3 and 0 to 0.5% Sb2O3. This glass has the same excellent features as the first described glass and, in addition, has further improved melt properties. |