Float-zone material was irradiated with 2MeV electrons at 140K in order to displace substitutional carbon atoms, Cs, into interstitial sites, Ci. The concentrations of the 2 species were determined from infra-red localized vibrational mode absorption measurements. Isothermal annealing at temperatures of between 297 and 331K revealed a loss of neutral Ci atoms under first-order kinetics, and the formation of di-carbon centers. From the known concentration of Cs traps, values for the diffusion coefficient were determined. These data (table 26), together with previous electron paramagnetic resonance reorientation data, gave:

D(cm2/s) = 0.44 exp[-0.87(eV)/kT]

A.K.Tipping, R.C.Newman: Semiconductor Science and Technology, 1987, 2[5], 315-7

Table 26

Diffusivity of Interstitial C in Float-Zone Si