Method and apparatus for processing a workpiece in a chemical bath liquid contained in a liquid container. The liquid container is fabricated from a material such as polyetheretherketone (PEEK), poly-amide-imide (PAI) or polyphenylene sulfide (PPS). A vibration generator is positioned on each of one or more container walls to introduce vibrations with a selected frequency (20-750 kHz) through the container wall(s) and into the chemical bath liquid. Two or more vibration generators may introduce vibrations with different frequencies into the chemical bath liquid and at different angles. The chemical bath liquid may be an acid such as HCl, H.sub.2 SO.sub.4, HNO.sub.3, H.sub.2 PO.sub.3 and HF, or may be an oxidizer or base such as NH.sub.4 OH and H.sub.2 O.sub.2. The chemical bath may be used to process semiconductor wafers and circuits, printed circuit boards, optical components and similar workpieces.