Author(s): Cowern NEB; Uppal S; Willoughby AFW; Bonar JM; Evans AGR; Morris R; Dowsett MG
Abstract: Results are presented of implantation and diffusion study of boron (B) in germanium (Ge). B implantation was carried out in Ge with different energies and to different doses. High-resolution secondary ion mass spectroscopy was used to obtain concentration profiles after furnace annealing. The as-implanted profiles show a long tail possibly due to enhanced diffusion. A limited diffusion has been observed after furnace annealing. Using T-SUPREM, diffusivity value of 1.5(±0.3)×10−16 cm2/s at 850°C has been extracted. This value is two orders of magnitude lower than previously reported values. The results question the change in diffusion mechanism of B diffusion in Si–Ge alloys from low Ge levels to high Ge levels.