A method includes loading a wafer over a wafer chuck in a process chamber; performing a deposition process on the loaded wafer; supplying a fluid medium to a fluid guiding structure in the wafer chuck from a fluid inlet port on the wafer chuck, the fluid guiding structure comprising a plurality of arc-shaped channels fluidly communicated with each other; guiding the fluid medium from a first one of the arc-shaped channels of the fluid guiding structure to a second one of the arc-shaped channels of the fluid guiding structure. The second one of the arc-shaped channels of the fluid guiding structure is concentric with the first one of the arc-shaped channels of the fluid guiding structure from a top view.