Transient ion drift experiments were used to obtain values for the intrinsic Cu diffusivity. On the basis of these measurements, Cu diffusion was found to be described by:
D (cm2/s) = 3.0 x 10-4 exp[-0.18(eV)/kT]
It was shown that the commonly used Hall-Racette expression gave an effective diffusion coefficient for heavily B-doped Si and could not be used for other doping levels or be extrapolated to lower temperatures. A model was developed which predicted the effective diffusion coefficient as a function of temperature, doping level and type of dopant.
Intrinsic Diffusion Coefficient of Interstitial Copper in Silicon A.A.Istratov, C.Flink, H.Hieslmair, E.R.Weber, T.Heiser: Physical Review Letters, 1998, 81[6], 1243-6
Table 38
Diffusivity of Cu in Si
Temperature (C) | D (cm2/s) |
117 | 4.5 x 10-8 |
102 | 2.4 x 10-8 |
87 | 1.5 x 10-8 |
82 | 1.0 x 10-8 |
72 | 7.0 x 10-9 |
72 | 1.7 x 10-8 |
67 | 3.6 x 10-9 |
62 | 5.0 x 10-9 |
57 | 1.0 x 10-8 |
52 | 2.8 x 10-9 |
47 | 6.4 x 10-9 |
42 | 3.0 x 10-9 |
37 | 1.9 x 10-9 |
37 | 4.0 x 10-9 |
27 | 2.3 x 10-9 |
17 | 1.4 x 10-9 |
9 | 4.8 x 10-10 |