METHOD FOR FORMING METAL INTERCONNECTION OF SEMICONDUCTOR DEVICE TO PREVENT COPPER THIN FILM FROM BEING OXIDIZED EVEN IF HIGH TEMPERATURE OXIDE PROCESS IS PERFORMED AND SIMPLIFY FABRICATING PROCESS

摘要

PURPOSE: A method for forming a metal interconnection of a semiconductor device is provided to prevent a copper thin film from being oxidized even if a high temperature oxide process is performed and simplify a fabricating process by patterning a metal layer while using a nitride layer as a mask such that the nitride layer has a low etch rate in performing a chlorine plasma etch process. CONSTITUTION: A copper metal layer(4), the second barrier layer(5) and the second insulation layer(6) are sequentially formed on a semiconductor substrate(1) having the first insulation layer(2) and the first barrier layer(3). The second barrier layer and the second insulation layer are nitridized to be transformed into the first nitride layer(7) and the second nitride layer(8). A selected region of the second nitride layer is firstly etched. By using an etch mask as the second nitride layer remaining after the etch process, the first nitride layer, the copper metal layer and the first barrier layer are secondly etched by a plasma etch process using chlorine plasma.