Ruthenium (Ru)-ruthenium oxide(RuO)/ ruthenium(Ru)-germanium(Ge)-copper(Cu) self-formed double-layer amorphous diffusion barrier layer and preparation method thereof

The invention provides a ruthenium (Ru)-ruthenium oxide (RuO)/ ruthenium(Ru)-germanium (Ge)-copper (Cu) self-formed double-layer amorphous diffusion barrier layer and a preparation method thereof. A diffusion barrier system comprises an underlay, a Cu(Ru) alloy film which is deposited on the underlay and is used as a seed layer and a precipitation layer, an amorphous Ru-Ge allloy film which is arranged between the underlay and the Cu(Ru) alloy film and is used as a pre-barrier and a use-up layer and a pure Cu layer which is coatred on the Cu(Ru) layer and is used as an interconnection layer. The self-formed barrier layer is continuous, uniform and dense, thickness of the barrier layer can be controlled within nanometers, low resistance and high heat stability can be realized, and the performance requirement of a ultra-large integrated circuit on the Cu interconnection diffusion barrier layer can be satisfied.