Patent ID: 6376386
Filing Date: 2002-04-23
Classification: H01L

Abstract:
A method of etching a silicon nitride layer comprising the steps of:forming a silicon nitride layer on a silicon layer or a silicon oxide layer above a substrate; loading the silicon layer or the silicon oxide layer and the silicon nitride layer in a dry etching atmosphere; and selectivity etching the silicon nitride layer with respect to the silicon layer or the silicon oxide layer by flowing a fluorine compound gas consisting of any one of CH2F2, CH3F, and CHF3 and an inert gas to the dry etching atmosphere, wherein a flow rate of the fluorine compound gas is set to 5 to 50 sccm, a flow rate of the inert gas is set more than three times a flow rate of the fluorine compound gas, a pressure of the dry etching atmosphere is set to 10 to 500 mTorr, and a RF power applied to the silicon nitride layer is set to 1.1 to 5.5 W/cm2, and a temperature of said substrate is set 20Â° C. to 95Â° C. so as to enhance an etching selectivity of the silicon nitride layer with respect to the silicon layer or the silicon oxide layer.