Method for rendering non-platable semiconductor substrates platable

Claim 1

A process for rendering a non-platable substrate platable by conventional electroless plating, said process resulting in the deposition of metallic sites, said sites being catalytic to said conventional electroless plating, said substrate selected from the group consisting of silicon, germanium, and III-V compounds, comprising the step of immersing said non-platable substrate into a promoter composition wherein said promoter composition is a single composition which comprises a suitable reducing agent and primary metal ions selected from the group consisting of nickel, cobalt, and iron wherein said reducing agent is capable of chemically reacting with said non-platable substrate and said primary metal ions and further wherein the concentration of said reducing agent relative to said primary metal ions is so adjusted as to permit the initial chemical interaction of the reducing agent with the non-platable substrate and then the heterogeneous reduction of some of the primary metal ions present in the promoter composition, and further wherein said promoter composition also comprises other metal ions selected from the group consisting of tin, cadmium, zinc, thallium, and lead and mixtures thereof, said other metal ions being present in a lower concentration relative to said reducing agent and in a sufficient concentration to inhibit the growth of said metallic sites and further wherein said process is prior to conventional electroless plating.