METHOD AND DEVICE FOR ETCHING SILICON NITRIDE

PROBLEM TO BE SOLVED: To etch a silicon nitride film at high speed and to suppress etching of a substrate of silicon nitride while preventing thermal damage to an object to be processed formed by coating the substrate with the silicon nitride film to be etched. SOLUTION: A processing gas including hydrogen fluoride and water is brought into contact with the object 90 to be processed to carry out etching. The etching includes two steps of a first etching step and a second etching step. In the first etching step, the object 90 to be processed is held substantially at room temperature, or preferably at 20 to 30°C. In the second etching step, the object 90 to be processed is held at 50 to 130°C, preferably at 60 to 110°C, or more preferably at 70 to 100°C. COPYRIGHT: (C)2011,JPO&INPIT