Metallic layers can be selectively deposited on one surface of a substrate relative to a second surface of the substrate. In some embodiments, the metallic layers are selectively deposited on copper instead of insulating or dielectric materials. In some embodiments, a first precursor forms a layer on the first surface and is subsequently reacted or converted to form a metallic layer. The deposition temperature may be selected such that a selectivity of above about 50% or even about 90% is achieved.