METHOD OF FORMING STORAGE NODE CONTACT OF CAPACITOR USING TWO-STEP ETCHING

摘要

PURPOSE: A method of forming a storage node contact of a capacitor is provided to maximize the size of a bottom in a storage node contact hole by using two-step etching processes. CONSTITUTION: A silicon nitride layer(102), a lower buffer layer(104), an upper buffer layer(106) and a hard mask are sequentially formed on a semiconductor substrate(100). The etching selectivity of the lower buffer layer is different from that of the upper buffer layer. A first etching process is selectively performed on the upper and lower buffer layers by using a first predetermined etching gas. The silicon nitride layer is secondly etched to form a storage node contact hole(110) with an improved profile by performing in-situ processing using a second predetermined etching gas.