A method for generating a radiation light in a lithography exposure system is provided. The method includes connecting a first nozzle assembly coupled to a support to an outlet of a storage member that receives a target fuel inside. The method further includes guiding the target fuel flowing through the first nozzle assembly and supplying a droplet of the target fuel into an excitation zone via the first nozzle assembly. The method also includes moving the support to connect a second nozzle assembly coupled to the support with the outlet. In addition, the method includes guiding the target fuel flowing through the second nozzle assembly and supplying a droplet of the target fuel into the excitation zone via the second nozzle assembly. The method further includes irradiating the droplet of the target fuel in the excitation zone with a laser pulse.