Lam Research Corporation
Manufacture of an orifice plate for use in gas calibration

Abstract:

Methods and systems for preparing a hole having an accurately controlled area in an orifice plate for a mass flow controller are provided. Methods involve forming an initial hole in the orifice plate. The initial hole has an opening having an initial area. The orifice plate comprises a material that can react to form a coating on the orifice plate. The coating occupies a greater volume than the material consumed to form the coating. The material of the orifice plate is reacted with a reactant to produce the coating and thereby produce a reduced area hole having an opening with a reduced area that is smaller than the initial area. The reduced area hole is measured. A determined amount of the coating is removed from at least the reduced area hole to produce a final hole in the orifice plate, wherein the reduced area is smaller than an opening area of the final hole.