Gas management apparatus and method for excimer laser

Abstract

The invention relates to a gas management apparatus and a method for an excimer laser. The apparatus comprises: an excimer laser; a monitoring and controlling module; controllable electromagnetic valves that are used for controlling flow directions of laser working gases; gas injection tank that is used for matching laser working gases with different concentrations; a halogen gas processing apparatus and a vacuum pump that are used for discharging laser working gases; and a pressure transducer that is used for monitoring pressure intensities of the laser working gases. According to the invention, working parameters of an excimer laser are monitored, wherein the working parameters include a working voltage, pulse energy, a width of a spectral line, and a wavelength; consumption of laser working gas is estimated according to quantitative relations between the working parameters of the excimer laser and the concentration of the laser working gas, wherein the working parameters are measured by an experiment; changes of pressure intensity of the laser working gas within a laser cavity as well as openings and closures of the controllable electromagnetic valves are controlled by employing pressure monitoring and signal feed back methods, so that the laser working gas is injected with an accurate value into the laser cavity. According to the invention, stability for outputting laser pulse by an excimer laser can be improved; life of laser working gas can be effectively prolonged; and a gas change rate of the laser can be reduced.

Description

technical field [0001] The invention belongs to the technical field of excimer lasers, in particular to a device and method for gas management of excimer lasers. Background technique [0002] Excimer lasers are widely used in industry, medical and scientific research fields, especially in the field of semiconductor lithography production, excimer lasers are used as light sources for lithography machines. KrF excimer lasers were used in lithography machines earlier, with an output wavelength of 248nm in the ultraviolet band. As the size of lithography nodes continued to decrease, they were replaced by shorter wavelength 193nm ArF excimer lasers. Both KrF and ArF are rare gas halide excimer lasers, and the working gas includes halogen gas F 2 , inert gas Ar or Kr, buffer gas Ne, inert gas He. [0003] f 2 The chemical properties of the laser are very active, especially when it is ionized into an ion state. Although the laser material is specially treated, the F 2 It will s...

AI Technical Summary

Problems solved by technology

The disadvantage is F 2 The concentration and working voltage vary widely, and it is difficult to precisely control the F in the laser 2 Concentration, laser output stability is not high

Use F 2 The gas management technology of concentration monitoring can monitor F in real time during laser operation 2 Concentration changes, through the flow controller and pressure control valve to control the flow rate of the inlet and outlet, respectively, to maintain the F in the laser 2 Concentration stability, although this method can precisely control F 2 Concentration, but the structure of the gas management device is complex and the cost is high

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