| 摘要 |
PURPOSE:To enable the main discharge to generate uniformly in the titled excimer laser as well as to enable the excimer laser to operate without causing the insulation deterioration thereof over a long term by a method wherein an alumina ceramic being constituted of alumina as its main component is used as the material for the dielectric, which is held between the auxiliary electrode and the main discharge electrode on one side of the two main discharge electrodes. CONSTITUTION:Two main discharge electrodes 1 and 2 are arranged in opposition to each other with the direction of the laser optical axis as the longitudinal direction and the main discharge electrode 2 on one side is constituted of a screening electrode 2b to be provided at its central part and supporting electrodes 2a and 2c to support the electrode 2b. An auxiliary electrode 3 to be used for making an auxiliary discharge 8 generate between the electrode 2 and the auxiliary electrode 3 is set up in the vicinity of the electrode 2. A dielectric 10 is made to interpose between the electrode 2 and the electrode 3 for making the auxiliary discharge 8 generate uniformly between the electrodes 2 and 3. As the material for the dielectric 10 is used an alumina ceramic being constituted of alumina; which is very high in insulating withstand voltage, and moreover, has a large specific inductivity, and furthermore, is inactive to halogen gas; as its main component. |
