The effect of crystallinity on the morphology of evaporated Al-Ge thin films

Al-Ge mixtures have been co-evaporated onto glass substrates heated to ∼ 180 °C. At this temperature both the Al and the Ge were crystalline. Electron micrographs show a random structure. Resistivity measurements give a percolation threshold also indicating a random structure. These results are in contrast to the granular aluminium in an amorphous Ge matrix which is obtained on room temperature substrates, and support the correlation between crystallinity and morphology in evaporated films, as proposed by Deutscher et al.