SELECTIVE DEPOSITION PROCESS

摘要

In the process for depositing metallic films in spatially selective regions on a semiconductor substrate (1), the substrate is illuminated with coherent photon energy which is selectively absorbed by patterned regions (6) of the substrate (1), which patterned regions (6) have accentuated absorption characteristics suitable to cause localized heating and pyrolytic reaction with selected ambient gases. The reactant gases are transparent to the illuminating radiation. Matching of the coherent photon energy wavelength with the photon absorption characteristics of the selected regions (6) in combination with pulsed operation of a laser (19) providing the photon energy can further localize the spatial selectivity. Optical free carrier absorption occurs preferentially in heavily doped regions, which regions are readily defined using known techniques for patterned doping. The deposited films thereafter act as nucleation sites for more conventional forms of chemical vapor deposition.