A study was made of the effect of a Ge+ pre-amorphization dose upon B diffusion and upon thermal evolution of the end-of-range defects during annealing. Amorphization was carried out by implanting 150keV Ge+ to doses ranging from 1015 to 8 x 1015/cm2. The B was subsequently implanted at 3keV, to a dose of 1014/cm2. Rapid thermal annealing was performed in N for various times and temperatures. Secondary ion mass spectroscopy and transmission electron microscopy were used to study B diffusion and defect evolution, respectively. It was found that, for a given annealing treatment, both the defect size and the B diffusivity were independent of the Ge ion dose. Increasing this dose resulted only in an increase in the defect density. The results were analyzed and this definitely confirmed that end-of-range defects were involved in a quasi-conservative Ostwald ripening process during annealing. The diffusive behavior of B suggested that the coupling of B atoms with the so-called mean field of Si interstitial atoms in dynamic equilibrium with the defects was responsible for transient enhanced diffusion.

Effect of the Ge Pre-Amorphization Dose on Boron Diffusion and Defect Evolution in Silicon. B.Colombeau, F.Cristiano, F.Olivie, C.Amand, G.Ben Assayag, A.Claverie: Nuclear Instruments and Methods in Physics Research B, 2002, 186[1-4], 276-80