A method includes attaching a carrier to a semiconductor wafer using a release film; removing the carrier from the semiconductor wafer; and performing a treatment process to remove the release film from the semiconductor wafer, the treatment process comprising: flowing an etchant through a diffusion plate within a treatment chamber, the diffusion plate comprising concentric rings separated by dividers, the concentric rings comprising a first concentric ring of holes, a second concentric ring of holes, and a third concentric ring of holes, each of the concentric rings having a different hole density; and performing a cleaning process on the semiconductor wafer.