Laser oscillating apparatus, exposure apparatus, and device fabrication method

摘要

An excimer laser gas in a laser tube 2 is excited by a microwave introduced from awaveguide 1, and electric field concentration occurs in a slit-shaped gap 3 provided in a plate member 11c, causing plasma discharge. Then the phase of plasma light is regulated and the light is resonated, to cause excimer laser light. This construction realizes plasma excitation entirely uniform along a lengthwise direction of laser light emission, and enables uniform laser light emission with minimum energy loss.