| 摘要 |
PROBLEM TO BE SOLVED: To allow selecting of an optimum operation range by reducing a charge voltage required for providing a desired pulse energy while measurement is possible, injecting at least a sufficient fluorine amount, and recording separate data set, which is repeated until a voltage is in a specified voltage range. SOLUTION: Laser is operated with a sufficient time for falling of a level that fluorine concentration corresponds to the upper limit of discharge voltage and desired pulse energy, and charge voltage, line width energy sigma, and estimated fluorine concentration are recorded. For generating the desired pulse energy, a fluorine amount is selected so that the difference in fluorine concentration corresponding to a minimum charge voltage is 1/10, and a fluorine concentration corresponding to maximum charge voltage is elected to operate laser for recording, and this procedure is continued until reaching the lower limit of voltage. Thus, selection of operation range is obtained as an optimum result considering all four parameters. |
