Methods and apparatus are provided for forming a metal or metal silicide layer by an electroless deposition technique. In one aspect, a method is provided for processing a substrate including depositing an initiation layer on a substrate surface, cleaning the substrate surface, and depositing a conductive material on the initiation layer by exposing the initiation layer to an electroless solution. The method may further comprise etching the substrate surface with an acidic solution and cleaning the substrate of the acidic solution prior to depositing the initiation layer. The initiation layer may be formed by exposing the substrate surface to a noble metal electroless solution or a borane-containing solution. The conductive material may be deposited with a borane-containing reducing agent. The conductive material may be used as a passivation layer, a barrier layer, a seed layer, or for use in forming a metal silicide layer.