| 摘要 |
PROBLEM TO BE SOLVED: To obtain an ArF excimer laser which performs a highly repetitive oscillating operation at 3 kHz or higher, and in which an oscillating laser pulse width Tis is made into long pulses at 30 ns or higher. SOLUTION: In this ArF excimer laser, a high repetition oscillating operation at 3 kHz or higher is performed. This ArF excimer laser is constituted in such a way that a laser oscillating operation is performed at a half cycle at the beginning of a one-pulse discharge oscillating current waveform, at which a polarity generated by a high-voltage pulse generating apparatus is inverted and at least at a half cycle succeeding that half cycle. A pressure inside the laser chamber of a laser gas is set at 2.5 to 3.5 atmospheric pressure, the fluorine concentration of the laser gas is set at 0.12 or lower, and the argon gas concentration of the laser gas is set at 3% or lower. Thereby, a laser pulse width Tis can be set at 30 ns or higher. |
