Diffusion of Cu and Ni into Ge was investigated between 700 and 900 °C with the aid of rapid isothermal lamp annealing and spreading-resistance profiling. Using low-dislocation-density single-crystal Ge wafers with a backside gold layer, we observed typical double-hump diffusion profiles of both Cu and Ni. These profiles can be described within the dissociative model by taking into account that the front surface acts as source for both vacancies (V) and Cu or Ni while the back surface combines the V-source feature with a Cu, Ni-sink property. Profile fitting yields data regarding the V-assisted Ge self-diffusion coefficient and the equilibrium concentration of vacancies as a function of temperature.

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We report out-diffusion experiments of Zn from homogeneously Zn-doped Si samples which were performed at 1107 °C. Depth distributions of Zn recorded by spreading-resistance profiling are accurately described on the basis of simultaneous contributions of the kick-out and dissociative diffusion mechanism. Analysis of the profiles reveals that Zn out-diffusion is mainly mediated by the dissociative mechanism. Fitting of Zn profiles yields data for the transport capacity of vacancies CVeqDV in Si and their thermal equilibrium concentration CVeq.

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We present out-diffusion of Zn in Si as a new method to study properties of Si vacancies. Out-diffusion experiments were performed on homogeneously Zn-doped Si samples at 1107°C and 1154°C. The resulting concentration-depth profiles were measured by means of spreading-resistance profiling. Based on a diffusion model in which Zn migrates simultaneously via the kick-out and the dissociative mechanism all experimental profiles were modeled by computer simulations. The calculations reveal that out-diffusion of Zn from Si occurs to a considerable extent via the dissociative mechanism. Hence, vacancy properties like the equilibrium concentration and the transport capacity can be extracted from profile fittings. The results are compared with literature data deduced from in-diffusion experiments.