The diffusion of self-atoms and n-type dopants such as P, As and Sb in Ge was studied by means of isotopically controlled multilayer structures doped with C. The diffusion profiles revealed an aggregation of the dopants within the C-doped layers and a retarded penetration depth compared to dopant diffusion in high-purity natural Ge. Dopant aggregation and diffusion retardation were strongest for Sb, and similar for P and As. In addition, the shape of the dopant profiles changed for dopant concentrations in the range of 1020/cm3, due mainly to the formation of dopant-vacancy complexes; which was more significant at high concentrations. Accurate modelling of the simultaneous self-diffusion and dopant diffusion was achieved on the basis of the vacancy mechanism and additional reactions that took account of the formation of neutral C-vacancy-dopant and neutral dopant-vacancy complexes. The stability of these complexes was compared with theoretical calculations published recently and with some additional calculations.The overall consistency between the experimental and theoretical results supported the stabilization of donor-vacancy complexes in Ge by the presence of C and the dopant deactivation via the formation of dopant-vacancy and C-vacancy-dopant complexes.

Diffusion and Defect Reactions between Donors, C, and Vacancies in Ge I - Experimental Results. S.Brotzmann, H.Bracht, J.Lundsgaard Hansen, A.Nylandsted Larsen, E.Simoen, E.E.Haller, J.S.Christensen, P.Werner: Physical Review B, 2008, 77[23], 235207 (13pp)

Table 2

Diffusivity of P in Ge