A system for processing a workpiece includes a process head assembly and a base assembly. The process head assembly has a process head and an upper rotor. The base assembly has a base and a lower rotor. The base and lower rotor have magnets wherein the upper rotor is engageable with the lower rotor via a magnetic force created by the magnets. The engaged upper and lower rotors form a process chamber where a semiconductor wafer is positioned for processing. Process fluids for treating the workpiece are introduced into the process chamber, optionally while the processing head spins the workpiece. Additionally, air flow around and through the process chamber is managed to reduce particle adders on the workpiece.