Etching method and methods of manufacturing semiconductor device using the same

Abstract

An etching method includes providing a plasma of a first treatment gas to an etching-object to form a deposition layer on the etching-object, the first treatment gas including a fluorocarbon gas and an inert gas, and the etching-object including a first region including silicon oxide and a second region including silicon nitride, providing a plasma of an inert gas to the etching-object having the deposition layer thereon to activate an etching reaction of the silicon oxide, wherein a negative direct current voltage is applied to an opposing part that is spaced apart from the etching-object so as to face an etching surface of the etching-object, the opposing part including silicon, and subsequently, providing a plasma of a second treatment gas to remove an etching reaction product, the second treatment gas including an inert gas and an oxygen-containing gas.