Influence of ion dose on nanostructure morphology and electrical properties of nitrogen implanted-annealed copper

Cu thin films sputter-coated on single crystals of silicon were implanted with 30 keV nitrogen ions under various doses from 1.9 × 10¹⁷ to 5.7 × 10¹⁷ ions/cm². The prepared samples were subsequently annealed in nitrogen atmosphere. The grazing incidence X-ray diffraction analysis revealed that in addition to the crystalline copper nitride phase, copper azides were developed by nitrogen ion implantation. With an increase of the implantation dose to 2.3 × 10¹⁸ ions/cm², much of the Cu film was transformed to the crystalline Cu₃N phase. Furthermore, the effect of nitrogen ion implantation on Cu thin films under various doses was investigated. The structural properties, morphology and sheet resistance of samples were investigated by grazing incidence X-ray diffraction, atomic force microscopy, field emission scanning electron microscopy and four-point probe techniques, respectively. In addition, the dependence of resistivity of the implanted samples on the implantation dose as well as structural properties is discussed.