| 摘要 |
Semiconductor nitride film etching systems are provided using a hot phosphoric-acid-based treatment solution, wherein the systems contain means for measuring phosphoric acid concentration, silicon concentration, fluorine concentration, or specific gravity or a combination thereof, and additives of the treatment solution are controlled or the treatment solution is exchanged. The concentration of components of the treatment solution, particularly the concentration of silicon, is controlled, thus providing stabilization of the etching rate of a silicon nitride film, and stable control of the etching selection ratio.
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