The adhesion of copper films deposited onto aluminum nitride

摘要

Good adhesion between copper film and AlN substrate is obtained when the surface of AlN is laser-irradiated prior to Cu film deposition and post deposition annealing is conducted. Surface chemistry of AlN substrates before and after laser irradiation and the interfacial reactions of Cu film/AlN couples were studied with Auger Electron Spectroscopy (AES) to understand the adhesion mechanisms. The surface of as-received AlN substrates was covered with a thin sheath of Al sub 2 O sub 3 . Laser irradiation removed the surface Al sub 2 O sub 3 layers, smoothened the surface, and decomposed AlN leaving metallic aluminum on the surface. The interfacial reactions in the Cu film/AlN couple are affected by the amounts of oxygen and metallic Al available at the interface. The adhesion mechanism is the formation of a Cu-O-Al compound at the interface of Cu film/AlN couple. Since Cu does not react with AlN, laser induced decomposition of AlN seems to be the driving force for the formation of the compound.