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Composition control and flexibility through novel bimetallic precursors

Bimetallic precursors for FEBID are expected to enable the fabrication of deposits with optimum composition control and reproducibility. The stoichiometry of the complex defines the ratio of the metals to be deposited independent of pressure fluctuations that are a concern in dual source processes. Following this approach, the novel precursor HFeCo3(CO)12 was synthesized and shown to yield FeCo3 metallic phases with predefined stochiometry and metal content up to 80%:

The high metal content of HFeCo3(CO)12 correlates with a surprising wealth of fragmentation channels through DEA that extend up to electron energies of 20 eV:

Interestingly, another new precursor H2FeRu3(CO)13 performs less favourably in FEBID yielding deposits with much lower metal content and Fe content below the precursor stoichiometry. This is in line with the fundamental electron-induced fragmentation that reveals a tendency towards metal-metal bond dissociation:

Further increased flexibility in fabrication has been demonstrated by combining a bimetallic precursor with a second precursor. This approach was exploited to fabricate nanopatterned layers in a direct-write process: