Electronic device-quality Cu was deposited on Pt-patterned oxidized Si wafers from hexafluoroacetylacetonate-copper(I)-trimethylvinylsilane by using low-pressure chem. vapor deposition at 150-250 Deg in He carrier gas. Smooth Cu films ?0.8 mm thick have been deposited with an elec. resistivity close to that of bulk Cu. From the temp. dependence of the mean deposition rate, an apparent activation energy of 53-62 kJ/mol was detd. for the overall deposition process. Monitoring of the deposition process by reflection of diode laser beams allowed an early detection of nucleation and film growth on both metal-seeded and unseeded surface sites. By the addn. of water to the reaction mixt., the nucleation on Pt-seeded SiO2 was accelerated, whereas the nucleation on unseeded SiO2 was delayed. Compared to deposition without water, the overall deposition rate on Pt-seeded SiO2 was slightly increased. However, the deposits showed a rough surface structure, and the film resistivity increased to >=20 mW-cm.