Abstract: Apparatus and method for removing material adhering to a workpiece are disclosed. A process liquid and a discontinuous phase are placed in a process tank adapted to receive a workpiece. The interface between the process liquid and the discontinuous phase is energized with megasonic energy, and the interface is contacted with and moved relative to the workpiece in a linear direction at a controlled rate, preferably across all of the workpiece. Liquid in the interface is optionally removed from the process tank at predetermined times to remove entrained particles. Numerous drying schemes can be used to reduce or eliminate formation of droplets and to speed drying time.

Abstract: Method and apparatus is disclosed for displacing a process fluid to effect agitation thereof in a laminar flow relation past a work piece being treated by the fluid. Where the process fluid comprises a liquid, a logic circuit is operative to oscillate the liquid by raising and lowering the liquid level about the work piece in a controlled cycle and stroke. Where the process fluid comprises a gas, the process gas is displaced or compressed and decompressed about the work piece in a controlled operating cycle. Various embodiments are disclosed for varying the operating parameters.