Characteristics of chemical-vapor-deposited copper on the Cu-seeded TiN substrates

Cu film was deposited by a MOCVD (Metal Organic Chemical Vapor Deposition) process on Cu-5, 40 Å, 130 Å seeded TiN and an as-received TiN substrate using 1,1,1,5,5,5-hexafluoroacetylacetonate-2,4-pentadionate (vinyltrimethylsilane) Copper(I) as a Cu precursor. The seeding process was carried out by PIBD (Partially Ionized Beam Deposition) process. By the presence of a seeding layer, the deposition rate of CVD-Cu films was slightly increased, the (111) preferred orientation was enhanced in the case of 130 Å seeding, and especially the continuity of Cu-grains was improved in the surface-reaction-limited region. The improvement of continuity decreased the resistivity of CVD-Cu films; minimum value of 2.42 μΩ · cm. After a vacuum (about 3 × 10^-5 Torr) annealing process at temperatures of 400, 500, and 600°C for 30 min, Cu grains grew and coalesced with each other. This sintering effect reduced the resistivity of CVD-Cu films and was prominent in the case of seeding.