| 摘要 |
PURPOSE: An etchant of silicon nitride film is provided to have an excellent selection ratio and an etching rate of nitride film, to prevent generation of foreign substances within a wafer, and to be able to be effectively utilized in etching a silicon nitride film in micro processes. CONSTITUTION: An etchant of silicon nitride film comprises 50-90 weight% of phosphoric acid, 10-3,000 ppm of silicon oxide film etching inhibitor, 1-500 ppm of silicon nitride film etching increasing agent, and residual portion of water to make 100 weight% of the total weight of the etchant. The silicon oxide film etching inhibitor is selected from the group consisting of polyacrylic acid, polyacrylamide, polyallyl ammonium, polyacrylamide - polyaryl ammonium copolymer, and their mixture. The silicon nitride film etching increasing agent is a fluoride compound. |
