Abnormal morphology of amorphous germanium films in contact with palladium

The fractal and dense branching morphologies of amorphous germanium films in contact with palladium have been investigated by TEM. The experimental results suggest that the production of fractal morphology in Pd/a-Ge bilayer films was easier than that in a-Ge/Pd bilayer films. An island-like fractal morphology can be formed at the step and crevice hole areas annealed at higher temperatures. It is difficult for co-evaporated Pd–Ge films to realize fractal morphology. The formation of fractal morphology can be explained by a RSN model. The SAED patterns suggest that the dense branching morphology cannot be completely demonstrated by the Pd, Ge, Pa2Ge, PdGe and Pd25Ge9, maybe it is a new phase.