The Effect of Ion-Bombardment-Induced Atomic Mixing on Depth-Profiling of Interfaces.
Abstract:
When a solid is subjected to energetic ion bombardment, relocation of atoms within the solid takes place due to collisional effects between the incoming ion and the target atoms and also due to creation of point defects. Such a process is known as atomic-mixing which clearly manifests itself in the degradation of the depth-profiles of interfaces obtained by sputter-sectioning in conjunction with a surface analytical technique such as secondary ion mass spectrometry SIMS, Auger electron spectrometry and x-ray photoemission spectrometry. By conducting SIMS depth-profiling of various siliconmetal multilayer structures in the temperature range 78K to 800K, the two contributions to atomic mixing were studied in detail. We found that ballistic mixing contribution at low temperatures can be adequately described by a diffusion model which leads to a deconvolution procedure to improve the depth resolution of SIMS depth-profiles. Keywords include Interfaces Multilayer structures ion-bombardment sputtering SIMS depth-profiles depth resolution ballistic mixing cascade mixing preferential sputtering radiation-enhanced diffusion.