Ge-containing Co-film forming material, Ge-containing Co film and film forming method thereof

To provide a film forming material and a film forming process for forming, at a lower temperature, a Ge-containing Co film including a desired amount of Ge. A film forming material for forming a Ge-containing Co film according to the invention is represented by either formula (1) or formula (2) below R1R2R3Ge-Co(CO)4 (1) (where R1, R2 and R3 are each independently hydrogen, a nonaromatic hydrocarbon group, a halogeno group or a halogenated nonaromatic hydrocarbon group; however, the nonaromatic hydrocarbon group excludes a crosslinked nonaromatic hydrocarbon group, and the halogenated nonaromatic hydrocarbon group excludes a crosslinked halogenated nonaromatic hydrocarbon group) Co(CO)4R4R5Ge-Co(CO)4 (2) (where R4 and R5 are each independently hydrogen, a nonaromatic hydrocarbon group, a halogeno group or a halogenated nonaromatic hydrocarbon group; however, the nonaromatic hydrocarbon group excludes a crosslinked nonaromatic hydrocarbon group, and the halogenated nonaromatic hydrocarbon group excludes a crosslinked halogenated nonaromatic hydrocarbon group).