Properties of Ru thin films fabricated on TiN by metal-organic chemical vapor deposition

Ruthenium (Ru) thin films were fabricated on TiN, as well as on SiO2, by metal-organic chemical vapor deposition using tris(2,4-octanedionato)ruthenium. We characterized the Ru films grown on TiN, and compared them with the films prepared on SiO2. The Ru films deposited on TiN showed weak crystallinity and random grain orientation similar to the films on SiO2, but revealed notably rougher surfaces than the films on SiO2. Moreover, deposition rates on TiN were lower than those on SiO2. These properties of the Ru films grown on TiN originated from the difficulties in nucleation and growth at the initial stage of the deposition. The inferior Surface flatness and deposition rate could cause structural instability and poor coverage of the Ru electrode at the bottom of a deep concave hole for a three-dimensional capacitor where the Ru film was in contact with a diffusion barrier metal TiN plug.