abstract |
In one aspect, the present invention provides an etching solution capable of increasing the etching rate ratio of a silicon nitride film to a silicon oxide film.nIn one aspect, the present invention relates to an etching solution, which is used in the step of removing the silicon nitride film from a substrate having a silicon nitride film and a silicon oxide film, and a solution containing silicon dioxide and alkali is prepared , Phosphoric acid, and water. |