Abstract: A method for forming a contact hole in a semiconductor device is disclosed. The method for forming a contact hole in a semiconductor device comprises depositing a nitride layer and an ILD on a substrate including predetermined devices; forming a first photoresist pattern on the ILD and making a via hole by using the first photoresist pattern; performing a first ashing process; forming a second photoresist pattern on the ILD and making a trench using the second photoresist pattern; conducting a PET; performing a second ashing process and etching the predetermined portion of the nitride layer exposed through the via hole; and wet-cleaning the resulting structure. Accordingly, the present disclosure can fabricate a contact hole maximizing the characteristics of a semiconductor device just by performing a Post Etching Treatment after a trench is formed.

Abstract: Methods of preventing oxidation of a copper interconnect of a semiconductor device are disclosed. An example method forms a lower copper interconnect on a substrate having at least one predetermined structure, deposits a nitride layer on the lower copper interconnect and on the substrate, and sequentially depositing a first insulating layer, an etch-stop layer, and a second insulating layer on the nitride layer. The example method also forms a trench and a via hole through the second insulating layer and the first insulating layer by using a dual damascene process, etches the nitride layer so as to expose some portion of the lower copper interconnect, and supplies combining gas onto the exposed portion of the lower copper interconnect.