Ruthenium complexes and process for producing ruthenium film

A complex of Formula (I) or Formula (II) is provided: wherein R2-R5 are each independently selected from a C1 to C6 hydrocarbyl group on the condition that the total of R2 and R4 combined is 2-7 and the total of R3 and R5 combined is 2-7. R2, R3, R4 and R5 are preferably methyl. A chemical deposition process for producing a ruthenium film using the ruthenium complex as a precursor is provided. The chemical deposition method may be either a chemical vapor deposition or an atomic layer deposition method. A method of preparing the complex comprising the step of reacting together a (η5-2,4-dimethylpentadienyl)(CH3CN)3 ruthenium (II) salt and an α,β-unsaturated carbonyl compound of the formula R2C(=O)CH=CR4CH3 or CH(=O)CR3=CHCH2R5 is provided. The compound (η5-2,4-dimethylpentadienyl)( η5-2,4-dimethyl-1-oxa-pentadienyl) ruthenium (II) [Ru(DMPD)(DMOPD)] is prepared using mesityl oxide as the α,β-unsaturated carbonyl compound. The compound (η5-2,4-dimethylpentadienyl)( η5-3,4-dimethyl-1-oxa-pentadienyl) ruthenium (II) [Ru(DMPD)(3,5-DMOPD)] is prepared using 2-methyl-2-pentenal as the α,β-unsaturated carbonyl compound.