Hot-Wire-Assisted Atomic Layer Deposition of High-Quality Ru Thin Films in the Absence of Oxidization

Continuous, atomically ultra-thin smooth ruthenium (Ru) films were deposited via hot-wire-assisted atomic layer deposition (HW-ALD) of ruthenocene and NH3. The behavior was self-limiting and no incubation cycle was required. The films were relatively pure at all deposition temperatures; the lowest resistivity was 17 mu Omega-cm for a 30.6-nm-thick film after post-annealing. The effective work function was 4.83 +/- 0.05 eV, comparable to that of sputtered films. As HW-ALD does not induce plasma damage or oxidation of the underlayer, which is fatal when preparing thermal and plasma-enhanced ALDs, the technique enables highly reliable device fabrication coupled with high conformality. (C) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.