In the laser gas of the ArF excimer laser which the laser gas of the ArF excimer laser,

摘要

PROBLEM TO BE SOLVED: To obtain an ArF excimer laser capable of increasing pulse frequency without enlarging equipment, and an aligner using the high pulse frequency ArF excimer laser as a light source. SOLUTION: A semiconductor chip on a wafer is divided into a plurality of irradiation regions 46. Each of the regions is irradiated with a plurality of pulses of a laser light 11, one by one. When exposure of one irradiation region 46 is finished, the next irradiation region is exposed. Thus the whole part of the semiconductor chip is exposed. In this scanning type aligner 40, an ArF excimer laser 1 in which the main component of buffer gas in laser gas is He and preferably Xe is contained in the laser gas is used as a light source oscillating the laser light 11.