Chemical vapor deposition of copper film from hexafluoroacetyl-acetonateCu (I)vinylcyclohexane

Abstract

An organometallic precursor, (hexafluoroacetyl-acetonate, hfac)Cu (I)(vinylcyclohexane, VCH) was studied for metallorganic chemical vapor deposition of copper thin films. The vapor pressure of (hfac)Cu (I)(VCH) is approximately 0.1 torr at 40°C and no appreciable amount of precipitation was observed while holding at 65°C for 1 month. The resistivity, purity, texture, adhesion, conformality and surface morphology of the film were investigated. The (hfac)Cu (I)(VCH) allowed the deposition at temperatures as low as 75°C. Copper film had a low resistivity of approximately 2.0 μΩ·cm for deposition temperatures ranging from 125 to 175°C. The copper film on physical vapor deposition (PVD) TiN was continuous and smoother than on chemical vapor deposition (CVD) TiN. The concentration level of impurities, including C, F and O at the interface was lower on PVD TiN than on CVD TiN. Films deposited at higher temperature showed better adhesion. It is believed that (hfac)Cu (I)(VCH) is stable with low vapor pressure and suitable as a precursor for seed layer formation with conformal coverage.