| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of regenerating an etchant targeting an etchant of silicon nitride and/or silicon nitride oxide containing sulfuric acid, extremely easily removing a silicon compound produced in the etchant, suitable for an industrial process, reducing regeneration process expense of the etchant, and capable of reducing waste liquid. SOLUTION: Silicon nitride and/or silicon nitride oxide is etched by an etchant containing sulfuric acid, fluoride and water, and thereafter the etchant is heated and/or depressurized to remove a silicon compound produced by the etching. COPYRIGHT: (C)2010,JPO&INPIT
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