Abstract: An apparatus and method for depositing a layer of a surface-compatible material from the fluid phase onto a selected surface of a substrate body in a fluid deposition chamber features a laser source of optically focused energy directed toward the body surface in a selected pattern. The energy is focused at a position adjacent the selected surface. Apparatus is provided for introducing a fluid medium adjacent the surface of the body. The medium has at least one component which absorbs a portion of the incident laser energy at the selected frequency for effecting photodecomposition or photolysis of the component in the fluid phase. Thereby, the product(s) of the photolysis process are deposited in the selected pattern on the substrate surface. The pattern may be fixed in position or may be optically or mechanically scanned across the substrate body. Thereby, metal layers, metal interconnects, pn junction and ohmic contact forming layers, selectively doped regions, etc.