An Optimized Dependency Eliminating Space-Shared Scheduling Algorithm

Method and apparatus for chemical treatment of workpieces is disclosed wherein a workpiece to be processed is exposed to a controlled gaseous atmosphere containing a gaseous constituent to be dissociated by laser radiation to produce a gaseous reactant product for reaction with a surface of the workpiece for chemical processing of the workpiece. The wavelength of the laser beam radiation is selected for splitting only the desired bonds to produce only the desired reactant product without producing undesired by-products which could deleteriously interfere with the desired chemical reaction. Specific examples of the desired laser induced dissociation to produce desired reactant products include, but are not limited to: dissociation to produce reactive oxygen for chemical reaction with photoresist for removing, or "ashing" the photoresist, laser induced dissociation of halocompounds to produce reactive halogen or halogen compounds for metal etching; and laser induced dissociation of fluorocompounds to produce reactive fluorine of fluorocompounds for selective etching of siliconiferous, metallic, or ceramic materials. The method and apparatus of the present invention is especially well suited for semiconductor wafer processing.