The diffusion behavior of ion-implanted As and P in relaxed Si0.8Ge0.2 was investigated (figure 5). Both dopants were observed to diffuse faster in SiGe, than in Si, under equilibrium extrinsic conditions. Simulations of the measured profiles suggested that the ratio of the effective diffusivity in Si0.8Ge0.2, as compared with that in Si, was

approximately equal to 7 for As, and to about 2 for P. The As diffusivity in SiGe was retarded under transient diffusion conditions, and the magnitude of the diffusion was roughly the same as that in Si.

Comparison of Arsenic and Phosphorus Diffusion Behavior in Silicon–Germanium Alloys. S.Eguchi, J.L.Hoyt, C.W.Leitz, E.A.Fitzgerald: Applied Physics Letters, 2002, 80[10], 1743-5

Figure 5

Diffusivity of As and P in Si0.8Ge0.2

(Open circles: P in SiGe; filled circles: P in Si;

open squares: As in SiGe; filled squares: As in Si)