Systems and methods for thermal treatment of a workpiece are provided. In one example, a method for conducting a treatment process on a workpiece, such as a thermal treatment process, an annealing treatment process, an oxidizing treatment process, or a reducing treatment process in a processing apparatus is provided. The processing apparatus includes a plasma chamber and a processing chamber. The plasma chamber and the processing chamber are separated by a plurality of separation grids or grid plates. The separation grids or grid plates operable to filter ions generated in the plasma chamber. The processing chamber has a workpiece support operable to support a workpiece.