Patent ID: 8130365

Claim:
An immersion flow field maintenance system for an immersion lithography machine, the lithography machine including a projection objective lens, at least a wafer stage for supporting a wafer, and an immersion supplying system distributed around the projection objective lens for producing an immersion flow field under the projection objective lens, characterized in that the immersion maintenance system includes a horizontal guideway, a flat board connected with the horizontal guideway through a cantilever, and plural drivers for driving the flat board to move; when the wafer is unloading and the wafer stage is moving out of the exposure area under the projection objective lens, the flat board connects to and moves synchronously with the wafer stage to transfer the immersion flow field from above the wafer stage to above the flat board; when the wafer is loaded and the wafer stage is moving into the exposure area, the flat board connects to and moves synchronously with the wafer stage to transfer the immersion flow field from above the flat board to above the wafer stage; and when the lithography machine carries out exposure, the flat board is moved to the periphery of the projection objective lens driven by horizontal drivers and is raised over the wafer stage driven by vertical drivers without interfering with the movement of the wafer stage carrying out exposure.