Transient enhanced diffusion from decaborane molecular ion implantation

Transient enhanced diffusion (TED) from implantation of 5 keV B10H14 and 0.5 keV B ions has been quantified and compared for nominal boron doses of 1014 and 1015 cm−2. Boron diffusivity during annealing was extracted from secondary ion mass spectroscopy depth profiles of diffused marker layers in boron doping-superlattices and the actual implanted B dose was independently measured by nuclear reaction analysis. Comparable enhancements were observed from both ions. Transmission electron microscopy analysis revealed that both boron- and decaborane-implanted samples were amorphized at a nominal 1015 cm−2 B dose. A comparison with data from low energy Si implants revealed a similar dependence of diffusivity enhancement on implant dose. These findings are consistent with the understanding that TED is caused by the interstitial supersaturation resulting from a number of excess interstitials approximately equal to the number of implanted atoms which can become substitutional in the silicon lattice. Accordingly, n...