Microchamber laser processing systems and methods using localized process-gas atmosphere

A microchamber system for processing a surface of a substrate, comprising:

• a top member having at least one optical-access feature sized to accommodate a laser beam that forms a laser line at the surface of the substrate;
• a movable stage assembly spaced apart from and that moves relative to the top member to define a chamber having a central region and a peripheral region, the movable stage assembly including a chuck that supports the substrate;
• a process-gas supply that contains a process gas and that is operably connected to the central region of the chamber by at least one process-gas conduit;
• a curtain-gas supply that contains a curtain gas and that is operably connected to the peripheral region of the chamber by at least one curtain-gas conduit;
• and
• a vacuum system operably connected to the chamber by at least one vacuum conduit that resides radially between the at least one process gas conduit and the at least one curtain-gas conduit so that when the process gas and the curtain gas are respectively flowed into the central and peripheral regions of the chamber, a localized process-gas atmosphere is formed in the central region of the chamber and a gas curtain of curtain gas is formed in the peripheral region of the chamber.