 struck with an rf power source 000 and creates plasma effluent 000 from discharge orifice 000 at one end of cavity 000 to clean substrate 000. In general, the shape and diameter of discharge orifice 000 may affect the corresponding shape of plasma effluent 000 along both the lateral and longitudinal axis (e.g., laterally narrow and longitudinally deep, laterally wide and longitudinally shallow, etc.). However, as previously stated, a large volume of inert gas may be required to prevent the generation of arc 000 between powered electrode 000 to grounded electrode 000. 