| 摘要 |
An etching solution, a process of producing the same, and an etching process using the same, in which the etching solution includes hydrofluoric acid (a), ammonium fluoride (b), and salt (c) formed between hydrogen fluoride and a base having a boiling point higher than that of ammonia; the concentration of ammonium fluoride (b) is not higher than 8.2 mol/kg, and the total amount of ammonium fluoride (b) and salt (c) formed between hydrogen fluoride and a base having a boiling point higher than that of ammonia is not less than 9.5 mol/kg. |
| 主权项 |
1. An etching process for a silicon oxide film comprising etching a silicon oxide film to be etched using an etching solution comprising: hydrofluoric acid (a); 0 to 8.2 mol/kg of ammonium fluoride (b); and a salt (c) formed between hydrogen fluoride and a base having a boiling point higher than that of ammonia, wherein the amount of hydrofluoric acid (a) is from 0.0005 mol/kg to not more than 0.5 mol/kg, and the total amount of ammonium fluoride (b), and the salt (c) formed between hydrogen fluoride and a base having a boiling point higher than that of ammonia is not less than 9.5 mol/kg, and
wherein the base having a boiling point higher than that of ammonia is at least one member selected from the group consisting of a primary amine, a secondary amine, a tertiary amine, and a quaternary ammonium compound, and wherein the primary amine is at least one member selected from the group consisting of methylamine, ethylamine, propylamine, butylamine, pentylamine, hydroxylamine, ethanolamine, propanolamine, butanolamine, methoxyethylamine and methoxypropylamine; and the secondary amine is at least one member selected from the group consisting of dimethylamine, diethylamine, dipropylamine and diethanolamine. |
