The diffusion of Pt into slightly-damaged regions of ion-implanted material was investigated by using deep-level transient spectroscopy and capacitance-voltage profiling. The samples consisted of PtSi/Si n-type Schottky diodes which had been implanted with O, F or Cl to a depth that was intermediate between the zero-bias and reverse-bias depletion boundaries, and had then been annealed at 700C. The distribution of in-diffused Pt was found by monitoring electron emissions from an acceptor level which had previously been attributed to Pt in a distorted substitutional configuration. The Pt was found to be distributed almost in parallel with the vacancy distribution that was generated during implantation. For a typical implantation dose of about 1011/cm2, there was an enhancement of the Pt accumulation by about 2 orders of magnitude; as compared with diffusion into non-implanted material. This apparent decoration of the primary damage profile occurred without the simultaneous introduction of other electrically active defects on a comparable scale. It was deduced that the residual damage which was present during annealing was sufficient to promote the accumulation to saturation of substitutional Pt in the region of primary implantation damage. This quite remarkable property of guided in- diffusion, a type of gettering phenomenon, was expected to have potential applications in device engineering.

B.Holm, K.B.Nielsen: Journal of Applied Physics, 1995, 78[10], 5970-4