An exemplary apparatus and method of forming a ruthenium tetroxide containing gas to form a ruthenium containing layer on a surface of a substrate is described herein. The method and apparatus described herein may be especially useful for fabricating electronic devices that are formed on a surface of the substrate or wafer. Generally, the method includes exposing a surface of a substrate to a ruthenium tetroxide vapor to form a catalytic layer on the surface of a substrate and then filling the device structures by an electroless, electroplating, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma enhanced CVD (PECVD), atomic layer deposition (ALD) or plasma enhanced ALD (PE-ALD) processes. In one embodiment, the ruthenium containing layer is formed on a surface of a substrate by creating ruthenium tetroxide in an external vessel and then delivering the generated ruthenium tetroxide gas to a surface of a temperature controlled substrate positioned in a processing chamber. In one embodiment, a ruthenium tetroxide containing solvent formation process is used to form ruthenium tetroxide using a ruthenium tetroxide containing source material. In one embodiment, of a ruthenium containing layer is formed on a surface of a substrate, using the ruthenium tetroxide containing solvent. In another embodiment, the solvent is separated from the ruthenium tetroxide containing solvent mixture and the remaining ruthenium tetroxide is used to form a ruthenium containing layer on the surface of a substrate.