METHOD FOR FORMING A METAL COATING ON A SUBSTRATE

摘要

A method for producing a uniform metal coating on a substrate consisting of (1) selecting one or more metals to be coated onto the substrate wherein the metals are soluble in a molten salt when heated, (2) preparing a bath consisting of the dissolved metal-molten salt, (3) inserting a substrate into the bath, and (4) decreasing the temperature at the substrate to a level at which the metal will precipitate out of solution onto the substrate. Multiple coatings can be made by repeating the method using the same or different metal-molten salt systems. Deposition can be enhanced by adding more salt to the bath to increase precipitation of the metal onto the substrate or by introducing additional metal into the bath by electrolysis, electrowinning or electrorefining. The metal coating can be patterned by localized heating of the metal coating in the metal-molten salt bath to reverse deposition or by masking areas on the substrate prior to deposition. The method can also be used to purify the metal being precipitated or to precipitate alloys or a metal containing impurities, such as doped GaAs, by controlling the composition and processing parameters of the metal-molten salt bath.