It has been shown by the Auger depth profiling technique that the concentra
tion profile at the initially sharp Si/Ge interface in amorphous Si/Ge mult
ilayers shifted but remained still sharp after a heat treatment at 680 K fo
r 100 h. At the same time the fast diffusion of Si resulted in the formatio
n of an almost homogeneous Ge(Si) amorphous solid solution, while there was
practically no diffusion of Ge into the Si layer. This is direct evidence
on the strong concentration dependence of the interdiffusion coefficient in
amorphous Si/Ge system, and it is in accordance with the previous indirect
result obtained from the measurements of the decay of the small angle Brag
g peaks, as well as with finite difference simulations. (C) 2001 American I
nstitute of Physics.