LASER IRRADIATION TYPE STEPPER OR SCANNER WITH ENERGY SENSOR FEED BACK

摘要

PROBLEM TO BE SOLVED: To adequately correct beam disturbance in a stepper etc., by constituting a laser irradiation type wafer exposure system having a first luminous intensity detector in the exposure system near a mask and second luminous intensity detector near a laser output unit. SOLUTION: A stepper 20 receives a laser beam 21 from a laser system 10 and finally forms an image of a mask pattern on a small section of a wafer 22 to expose a photo resist layer on the wafer 22. After application of a given no. of laser beam pulses, an X-Y table 24 steps the wafer 22 in the direction X and/or Y. After exposure of the wafer 22 a controller 26 controls the position of the table 24 according to a software routine. A mirror 45 and a photo detector 46 are used to measure the luminous intensity of the beam 21 at a laser output and shutter 47 controllably blocks the beam 21 from entering the stepper 20.