Multi-layers of MoxSiy/Si, with a period thickness of about 7.5nm, and bi-layers were fabricated by means of electron-beam evaporation in ultra-high vacuum at a deposition temperature of 150C. The as-deposited layer systems were studied by means of high-resolution Rutherford back-scattering spectrometry. In multi-layers with a mixing ratio, y/x, of about 2, no interdiffusion was observed up to a temperature of 830C. In the case of samples with a mixing ratio, y/x, that was close to unity, diffusion was observed up to a temperature of 630C. This resulted in a mixing ratio that was close to 2. This mixing ratio remained almost stable up to about 830C, and appreciable interdiffusion was observed only in those systems where regions with a mixing ratio that was smaller than 2 still existed. It was suggested that a possible reason for the high thermal stability of the samples was the lack of a Si concentration gradient in the system.

B.Heidemann, T.Tappe, B.Schmiedeskamp, U.Heinzmann: Zeitschrift für Physik B, 1995, 99[1], 37-42