| abstract |
An etchant composition useful for etching an indium oxide-based layer capable of forming thin lines having a desired linearity with little narrowing by etching and good linearity even if it does not contain hydrogen chloride width, the etching solution composition contains: (A) 0.01 to 15% by mass of hydrogen peroxide; (B) 1 to 40% by mass of sulfuric acid; (C) (C-1) following general formula (1) (R 1 , R 2 and R 3 : hydrogen, an alkyl group having 1 to 8 carbon atoms, etc.), 0.01 to 10% by mass of an amide compound represented by (C-2) 0.01 to 20% by mass of an amino acid compound; and water. |