Supercritical fluid chemical deposition of Cu in Ru and TiN-lined deep nanotrenches using a new Cu(I) amidinate precursor

• Published in: Microelectronic engineering 2015-04, Vol.137, p.32-36
• Main Authors: Rasadujjaman, Md, Watanabe, Mitsuhiro, Sudoh, Hiroshi, Machida, Hideaki, Kondoh, Eiichi
• Format: Article
• Language: English
• Subjects: ACETONE; Adhesion strength; CARBON DIOXIDE; Copper; Cu(I) amidinate; DEPOSITION; FLUID FLOW; MICA; MICROSTRUCTURES; Nanostructure; Nanotrenches; Precursors; Supercritical carbon dioxide; Supercritical fluids; Thin films; Titanium nitride
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2014.11.021

[Display omitted] •We report supercritical fluid chemical deposition of Cu films using a new non-fluorinated Cu(I) amidinate precursor.•High purity Cu films were grown at a lower deposition temperature (140°C).•On the Ru surface Cu nucleated densely, forming smooth and strongly adherent films.•At 140°C, the excellent filling capability of Cu in Ru- or TiN-lined nanotrenches. We report supercritical fluid chemical deposition (SFCD) of Cu films in Ru- and TiN-lined deep nanotrenches using a new non-fluorinated Cu(I) amidinate precursor. The Cu(I) amidinate precursor dispersed well in an acetone/CO2 solution with molecular hydrogen as the reducing agent at very low temperatures. High-purity Cu films were grown on both Ru and TiN substrates at a lower deposition temperature (140°C) than typical temperatures reported for CuII(hfac)2 and CuII(dibm)2 precursors. The temperature dependence of the growth rate was studied and the growth rates were determined to be 10–14nm/min and 6–13nm/min for Ru and TiN substrates, respectively, in a temperature range of 140–240°C. On the Ru surface, Cu nucleated densely, forming smooth, strongly adherent films. At 140°C, the excellent filling capability of Cu in Ru- or TiN-lined nanotrenches was demonstrated.