Samples were implanted with 120keV S+ ions to doses of between 3 x 1013 and 1015/cm2 (table 21). They were capped with an 80nm-thick film of amorphous hydrogenated Si, into which As was doped to a concentration of 2 x 1020/cm3. The samples were then annealed in Ar gas (850 to 1000C, 0.25h) giving:

1 x 1015/cm2:       D(cm2/s) = 2.0 x 10-9 exp[-0.80(eV)/kT]

5 x 1014/cm2:       D(cm2/s) = 9.0 x 10-9 exp[-1.00(eV)/kT]

1 x 1014/cm2:       D(cm2/s) = 4.2 x 10-7 exp[-1.50(eV)/kT]

5 x 1013/cm2:       D(cm2/s) = 5.5 x 10-7 exp[-1.60(eV)/kT]

It was found that the diffusivity of S (table 22) could be described by the expression:

D = Dm[KQ2/(1 + KQ2)]

where K was a constant, Q was the implantation dose, and Dm was the diffusivity of a mobile complex.

M.Sakaguchi, K.Yokota, A.Shiomi, K.Hirai, H.Takano, M.Kumagai: Japanese Journal of Applied Physics, 1996, 35[1-8], 4203-8

Table 21

Diffusivity of Implanted S in GaAs