Excimer laser with gas purification

摘要

An excimer laser system in which the expensive noble gases are reclaimed, while the halogen gas is sacrificed, and the impurities developed during operation of the excimer laser are removed. In the approach disclosed a multi-stage gas purifier is used with a single, premix gas bottle containing a halogen-rich laser gas mixture comprising noble, buffer and halogen gas, to maintain the optimum halogen content of the laser, while also maintaining a consistent ratio of noble, buffer and halogen gases without complicated control apparatus.

主权项

1. An excimer laser system comprising:
a laser chamber containing a laser gas mixture of a noble gas, a buffer gas and a halogen gas at operating concentrations for operating the laser, the laser chamber including a gas input port and a gas output port; a scrubber coupled to the gas output port for removal of the halogen gas; a gas purifier coupled between the scrubber and the gas input port for removing impurities from the noble and buffer gases; a pump for circulating the laser gas mixture out of the gas output port, and the noble and buffer gases back in the input port after purification; a gas supply bottle coupled to the laser chamber containing a halogen-rich laser gas mixture including the noble lasing gas and buffer gas at a ratio the same as the operating concentrations, and the halogen gas at above the operating concentration; and a controller for isolating the gas purifier from the laser chamber, for coupling the gas supply bottle directly to the laser chamber, and for supplying the halogen-rich laser gas mixture to replenish the halogen gas without affecting the relative concentration of noble and buffer gases; wherein the purifier includes a recirculation loop for passing the noble and buffer gases through the purifier a plurality of times before returning them to the laser chamber.