A method was presented which permitted the simultaneous  in situ  investigation of the relaxation and diffusion behavior, of SiGe layers on Si substrates, by using a conventional X-ray powder diffractometer with a high-temperature attachment. This method permitted the direct determination of the time and temperature dependences of the relaxation and of the maximum Ge content. The diffusivity of Ge in Si was monitored by means of X-ray diffraction and secondary ion mass spectroscopic measurements, and a non-linear dependence of the effective diffusion coefficient upon the Ge content was deduced by solving the diffusion equation. It was found that the Ge diffusivity was constant at about 8 x 10-17 (1006C) or 5 x 10-17cm2/s (993C), for Ge contents of between 1020 and 1021/cm3, and then increased sharply to values of about 5 x 10-16 (1006C) or 4 x 10-16cm2/s (993C) at a Ge content of 1022/cm3.

X-Ray in situ Observation of Relaxation and Diffusion Processes in Si1-xGex Layers on Silicon Substrates. P.Zaumseil, U.Jagdhold, D.Krüger: Journal of Applied Physics, 1994, 76[4], 2191-6