A process system for processing semiconductor wafers includes a stocker module, and immersion module, and a process module. A process robot moves on a lateral rail to transfer wavers between the modules. The immersion module is separated from the other modules, to avoid transmission of vibration. Immersion tanks are radially positioned within the immersion module, to provide a compact design. An immersion robot moves batches of wafers on an end effector between the immersion tanks. The end effector may be detachable from the immersion robot, so that the immersion robot can move a second batch of wafers, while the first batch of wafers undergoes an immersion process.