| 摘要 |
PROBLEM TO BE SOLVED: To provide a plasma light source that stably produces extreme ultraviolet light for a long period of time.SOLUTION: A plasma light source includes a pair of coaxial electrodes 10 and 10 that are arranged so as to face each other and that generate and confine therebetween plasma 3 that radiates extreme ultraviolet light. Each coaxial electrode 10 has: a bar-like center electrode 12 that extends on a single axis Z-Z; external electrodes 14 that are provided so to surround the outer boundary of the center electrode 12; and an insulator 16 that insulates the center electrode 12 and the external electrodes 14 from each other. In a side surface thereof facing the center electrode 12, each external electrode 14 has a protrusion 15 that protrudes toward the center electrode 12. |
