Point defects in silicon after zinc diffusion - a deep level transient spectroscopy and spreading-resistance profiling study

We present results from spreading-resistance profiling and deep level trans ient spectroscopy on Si after Zn diffusion at 1294 K. Concentration profile s of substitutional Zn, in dislocation-free and highly dislocated Si are de scribed by a diffusion mechanism involving interstitial-substitutional exch ange. Additional annealing at 873 K following quenching from the diffusion temperature is required in the case of dislocation-free Si to electrically activate Zn,. The formation of complexes of Zn, with unwanted impurities up on quenching is discussed. Additional Ni diffusion experiments as well as t otal energy calculations suggest that Ni is a likely candidate for the pass ivation of Zn,. From total energy calculations we find that the formation o f complexes involving Zn and Ni depends on the position of the Fermi level. This explains differences in results from spreading-resistance profiling a nd deep level transient spectroscopy on near-intrinsic and p-type Si, respe ctively.