The results of positron annihilation (Doppler broadening) experiments were analyzed by using Monte Carlo implantation profiles. The computer program was modified so that scaled parametrized multi-layer profiles could be used as initial conditions for the solution of the diffusion equation. Both elemental (such as amorphous Si) and multi-layer (such as Pd/Si) systems were considered. Strong correlations were found between the input implantation profile parameters and the values which were obtained for the diffusion lengths and over-layer thicknesses in multi-layer systems. The effect of uncertainties, in the mean depth, upon the value of the diffusion length and thus the defect concentration, was analyzed.

V.J.Ghosh, B.Nielsen, K.G.Lynn, D.O.Welch: Applied Surface Science, 1995, 85, 210-5