Low temperature formation of copper rich silicides

The reactions of copper and amorphous silicon were studied by in-situ transmission electron microscopy up to 500 degrees C. Only the Cu76Si24-eta phase and the Cu82Si18-delta phase formed at this temperature. The crystal structure of the dominating Cu76Si24 changed, by the elapsed time after heating. The Cu-Si ordering resulted in different supercells, built up by topologically identical subcells with different site occupancies and arrangement. Two modulated crystal structures were solved based on diffraction data and HRTEM images