DRY ETCHING METHOD OF SILICON NITRIDE FILM AND METHOD OF MANUFACTURING THIN-FILM TRANSISTOR

摘要

PROBLEM TO BE SOLVED: To successfully perform dry etching of a silicon nitride film on a genuine amorphous silicon film without using gas such as SF6which contributes to global warming. SOLUTION: The silicon nitride film 22 is formed on the upper surface of the formed genuine amorphous silicon film 21, and a resist film 23 is formed on the upper surface of the silicon nitride film 22. Then, when reactive-ion etching using mixture gas of fluorine gas (100 sccm) and oxygen gas (100-400 sccm) as etching gas is performed, the dry etching of the silicon nitride film 22 in areas under the resist film 23 is performed, and its etching rate is about 2,000 Å/min. In this case, when the silicon nitride film 22 is completely removed, the genuine amorphous silicon film 21 of the ground is exposed, the dry etching of the exposed genuine amorphous silicon film 21 is performed to some extent, and its etching rate is about 400 Å/min. Consequently, selection ratio in this case is about 5. COPYRIGHT: (C)2010,JPO&INPIT