Microstructure of silicon implanted with MeV gold ions
High-energy implantation of silicon is of great interest in recent years for microelectronics due to the formation of a buried damage or dopant layer away from the active region of the device. The damage nucleation and growth behavior is known to vary significantly along the ion's track for MeV irradiation. In this paper, a detailed characterization of the damage morphology produced by MeV gold ions for different doses into single crystal Si, as well as the associated annealing behavior, is presented.Single crystal n-type Czochralski silicon {001} wafers were implanted with Au++ ions from doses of 1x1015 to 3x1016 cm-2 at 2-3 MeV. Specimen temperatures for all implantations were 20 or 300°C. A measurement with an infrared pyrometer of the implanted surface indicated a slight temperature rise during ion irradiation. The compositional and damage profiles were determined by Rutherford backscattering/channeling spectroscopy (RBS). Cross-sectional TEM samples for microstructural characterization were prepared by mechanical polishing and ion milling. A Philips 400ST/FEG analytical microscope was used for nanoprobe experiments, at 100 kV. Microstructural investigation was performed using ISI-002B and JEM-2000FX microscopes, at 200 kV.