Plasma etching method
View Patent ↗It is an object of the present invention to provide a plasma etching method that can improve a selection ratio of a film to be etched to a film different from the film to be etched than that in the related art. The present invention provides a plasma etching method for selectively etching a film to be etched with respect to another film different from the film to be etched, the plasma etching method including etching, using gas that can generate a deposited film containing components same as components of the another film different from the film to be etched, the film on which generation of the deposited film is suppressed.
1. A method for selectively etching a silicon nitride layer in comparison with a silicon oxide layer, wherein the silicon nitride layer is etched using a mixed gas comprising a fluorocarbon gas, a gas including oxygen and a SiF 4 gas.
2. The method according to claim 1 , wherein the mixed gas further comprises an inert gas.
3. The method according to claim 1 , wherein the fluorocarbon gas includes a CH 3 F gas, and the gas including oxygen includes an O 2 gas.
4. A method for selectively etching a silicon nitride layer in comparison with a silicon oxide layer, wherein the silicon nitride layer is etched using a mixed gas comprising a CH 4 gas, a gas including fluorine, a gas including oxygen and a SiF 4 gas.