[(1,5-cyclooctadiene)(toluene)ruthenium(0)]: a novel precursor for the MOCVD of thin ruthenium films

MOCVD of [(1,5-cyclooctadiene)(toluene)Ru0] on copper and silicon substrates in a vertical cold-wall reactor led to the formation of thin metallic ruthenium films with low carbon content. The deposition was carried out by varying the substrate temperature (150-450 C), total pressure (100-500 mbar) and mean residence time (0.17-0.50 s). It was found that Ru films could be deposited at temperatures as low as 150 C. The exhaust gas was analyzed by gas chromatography (GC) and the deposited films were characterized by energy dispersive analysis of X-rays (EDX) and elastic recoil detection analysis (ERDA). A correlation was found between the carbon content of the films and the presence of chemically modified ligands in the MOCVD exhaust gas. 1,5-Cyclooctadiene was identified as the main source for carbon incorporated into the deposited Ru films. C-H activation at the metallic ruthenium surface was regarded as the primary process of ligand degradation, which led to final carbon contamination. (Abstract Copyright [2005], Wiley Periodicals, Inc.)