| 摘要 |
PROBLEM TO BE SOLVED: To enhance energy dose control and reproducibility by suppressing the partial pressure of fluorine below a specified percentage and increasing the reflection of an output coupler above a specified percentage. SOLUTION: A narrow frequency band excimer laser comprises a laser chamber 8 made of a material coexisting with fluorine provided with two elongated electrode rods and at least a pre-ionization unit and filled with a laser gas composed of a rare gas, fluorine, a buffer gas and oxygen having concentration of 2-500 ppm with a total pressure being limited, and a beam intensifier module having at least one beam expansion prism, a lattice and a tuning means for lattice. In a preferred embodiment, partial pressure of fluorine is set lower than 0.10% and the reflection of an output coupler is increased to 25% or above. |
