| 摘要 |
PURPOSE:To form a fine pattern of an ITO by etching the ITO formed on the insulating layer of a substrate having electrode wirings made of aluminum or aluminum alloy with solution of specific temperature which contains specific amounts of sulfuric acid and ammonium sulfate. CONSTITUTION:Electrode wirings 3 made of aluminum or aluminum alloy are formed on an insulating substrate 20 as a circuit substrate 2, an interlayer insulator such as SiN and, in this case, an insulating film 4 is formed on the substrate 2, and a thin ITO film is then formed on the film 4. After this is patpterned by photoetching, it is etched, for example, with aqueous solution which contains 5-50wt% such as 10wt% of sulfuric acid and nitric acid with the liquid temperature at 50 deg.C or higher and lower than its boiling point such as 60 deg.C, thereby obtaining a patterned ITO1. In this case, even if defects 5, 6, 7 exist in the film 4, the ratio of the etching rates of the ITO and the aluminum or aluminum alloy is 15:1. Accordingly, the lower layer is not etched, and the wirings 3 made of the aluminum or aluminum alloy are not disconnected. |
