Gas distribution apparatuses and methods for controlling gas distribution apparatuses

摘要

A gas distribution apparatus includes a first plate and a second plate comprising a plurality of first openings and second openings, respectively. The second plate is disposed in overlapping relation with the first plate. Overlaps of the first openings and the second openings form third openings, which provide a first gas distribution pattern at a first orientation of the plates relative to one another and a second gas distribution pattern at a second orientation different than the first orientation.