Modeling of the effects of dose, dose rate, and implant temperature on transient enhanced diffusion

Atomistic simulations are used to study the effects of implant parameters on transient enhanced diffusion (TED). We analyze 10 keV Si implants in a wide range of doses from 10(8) to 10(14) ions/cm(2), dose rates from 10(10) to 10(14) ions/cm(2) s, and implant temperature from room temperature to 1000 degrees C. Different regimes with different dependence of TED on these parameters are observed. For high doses, high dose rates, and low implant temperatures, the Frenkel pairs are accumulated during ion implantation, and the resulting damage is very dense. During the postimplant annealing, the recombination of Frenkel pairs is efficient, and the extra interstitials generated by the implanted ions provide the main contribution to the enhanced diffusivity. For low doses, low dose rates, and high implant temperatures, there is little interaction between neighboring cascades during annealing. The recombination of Frenkel pairs is not complete, and many interstitials and vacancies from each cascade survive recombination and contribute significantly to TED. (C) 1999 American Institute of Physics. [S0003-6951(99)02214-7].