Surface and near surface structure and composition of high-dose implanted and electron beam annealed single crystal copper

Abstract

Cu(111),(100) single crystals implanted with Ti up to 8 × 10 17 cm −2 followed by high-current electron beam annealing (HCEB) have been investigated by means of transmission electron microscopy (TEM), Rutherford back-scattering (RBS), nuclear reaction elastic resonance (NRER) and scanning electron microscopy (SEM). Ti, O, C concentration profile behaviour in Cu single crystals has been studied. Cu layer structure after Ti implantation became multi-component. It was found that this layer included a surface amorphous carbon film, a layer consisting of TiC, a layer consisting of (110)CuTi/(111)TiC and a subsequent Cu single crystal possessing subgrains of 170–180 nm. A small-angle disorientation up to 5 ° between the subgrains was observed. As a result of HCEB irradiation, a portion of carbon film evaporated, and Ti carbide dispersed to 2–4 nm. The Cu structure essentially changed. The Cu layer contacting the carbide became a nano-dimensional substructure with an average crystallite size of 50–70 nm. At a depth of 0.1 μm the Cu structure is represented as a disoriented striped substructure: the discrete disorientation between the stripes was about 6–7 °. Net dislocation substructure was observed inside the stripes, the dislocation scalar density of which was < γ> = 5.2 × 10 10 cm −2.