Atomic layer deposition of Ru from CpRu(CO)2Et using O2 gas and O2 plasma

The metalorganic precursor cyclopentadienylethyl(dicarbonyl)ruthenium (CpRu(CO)(2)Et) was used to develop an atomic layer deposition (ALD) process for ruthenium. O-2 gas and O-2 plasma were employed as reactants. For both processes, thermal and plasma-assisted ALD, a relatively high growth-per-cycle of similar to 1 angstrom was obtained. The Ru films were dense and polycrystalline, regardless of the reactant, yielding a resistivity of similar to 16 mu Omega cm. The O-2 plasma not only enhanced the Ru nucleation on the TiN substrates but also led to an increased roughness compared to thermal ALD. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3554691]