| 摘要 |
A method for manufacturing a photomask is provided to minimize the generation of gas accompanied by wet etching, by setting a molar ratio of fluorine compound to oxidizing agent within etchant at a ratio that prevents pattern defects on a semi-transmissive film and/or a light shielding film. A photomask is manufactured by patterning a light shielding film(18) and a semi-transmissive film(17) of a mask blank(20) which comprises the semi-transmissive film capable of adjusting transmissivity to exposure light, and consisting a material containing metal and silicon, and the light shielding film shielding the exposure light that are successively formed on a light-transmissive substrate(16). The patterning of the semi-transmissive film is conducted by wet etching using etchant containing at least one fluorine compound selected one of hydrofluoric acid, hydrofluosilicic acid, and ammonium hydrogen fluoride, and at least one oxidizing agent selected one of hydrogen peroxide, nitride, and sulfuric acid. The etchant has a molar ratio of fluorine compound to oxidizing agent, to be able to prevent generation of pattern defects due to gas accompanied by wet etching. |
