METHOD FOR FORMING METAL INTERCONNECTIONS OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A metal interconnection formation method is provided to improve a reliability and to prevent a thermal budget by using a noble metal, such as iridium(Ir) as an etch stop layer. CONSTITUTION: A lower insulating layer(55) is formed on a semiconductor substrate(51). A contact hole is formed to expose a word line(53). A glue layer(57) of IrO2, an anti-diffusion layer(59) of TiN and an etch stop layer(61) of iridium(Ir) are sequentially formed on the entire surface of the resultant structure. A material layer for metal wire(63) of aluminum(Al) is filled into the contact hole. The metal wire(63) is then etched by using the etching selectivity between the Al metal wire(63) and the Ir etch stop layer(61).