A modular wafer edge processing apparatus is disclosed that overcomes the limitations of conventional edge processing methods and systems used in semiconductor manufacturing. The modular apparatus can be integrated into wafer tracks, cluster tools, and other volume manufacturing systems. The edge processing apparatus of this invention includes a laser that can either be contained inside the module, or mounted externally to feed multiple modules and thereby reduce system cost. The apparatus contains a beam delivery subsystem to direct a beam of radiation onto the edges of a rotating substrate supported by a chuck. The optical system accurately and precisely directs the beam to remove or transform organic or inorganic films, film stacks, residues, or particles, in atmosphere, from the top edge, top bevel, apex, bottom bevel, and bottom edge of the substrate in a single process step. Reaction by-products are removed by means of an exhaust tube enveloping the reaction site. This invention permits precise control of an edge exclusion width, resulting in an increase in the number of usable die on a wafer. Wafer edge processing with this invention replaces existing methods that use large volumes of purified water and hazardous chemicals including solvents, acids, alkalis, and proprietary strippers.