Deposition of substances on a surface

Abstract

Methods and apparatus are provided in which a coating is deposited onto a substrate by a process which includes the following steps: depositing a precursor onto the substrate in a desired pattern; depositing an appropriate ligand onto the substrate; and applying sufficient energy to transfer electrons from the ligand to the precursor, thereby decomposing the precursor to form a precipitate. In one aspect of preferred embodiments, the precursor comprises a metallic salt, and the precipitate comprises a metal. Especially preferred salts are carboxylates, halides, nitrates, and pseudo halides. In another aspect of preferred embodiments, the ligand comprises an amine, an amide, a phosphine, a sulfide, or any other ligand containing nitrogen, phosphorous, sulphur or other donor atoms. In another aspect of preferred embodiments, the energy is supplied at least partially as radiant heat. In another aspect of the preferred embodiments, the deposited material has a high purity of at least 80% by weight, a desired pattern is produced without removing from the substrate a substantial quantity of either the precursor or the deposited coating.