Abstract: A high Cv bulk process valve, control system and method convey a process gas or liquid for manufacturing semiconductors through a fluid passage. The fluid passage contains an aerodynamically shaped expansion chamber within which a valve seat and a moveable poppet are arranged for opening and closing the fluid passage. The aerodynamically shaped expansion chamber includes a conically expanding entry and a conically contracting exit and is shaped such that the resistance to flow of the process gas or liquid through the fluid passage of the valve is very nearly the same as through a straight tubing having a cross-sectional area of an inlet to the valve and a length of the fluid passage through the valve. The valve can be added or subtracted from a gas or liquid control system with virtually no changes in pressure drop of flow restriction, when the valve is in the open position. The valve minimizes the energy consumed by valves in semiconductor gas systems.

Abstract: A method and apparatus for cleaning surfaces to absolute or near-absolute cleanliness involves spraying jets of heated cleaning solution so that it flows over and scrubs the surfaces to be cleaned. The cleaning solution is continuously recirculated and filtered during cleaning to remove over 99% of all particles having a diameter equal to or greater than 0.02.mu.. The cleaned surface is rinsed with heated, filtered deionized water and dried to provide a surface having absolute or nearly-absolute cleanliness to the limit of the best commercial instrumentation, e.g., .ltoreq. five particles with a diameter of .gtoreq.0.02.mu. per cubic foot of gas flowed over a cleaned surface as detected by a laser particle counter. The method is useful for cleaning gas valves and regulators and components thereof as well as existing gas flow equipment, for example, for use in semiconductor processing equipment. The cleaned surfaces are sterile and therefore also useful in the health and pharmaceutical industries.