Segmented gas distribution plate for high-power, high-pressure processes

A gas distribution assembly for a substrate processing system, the gas distribution assembly comprising:

• a top plate;
• and
• a gas distribution plate comprising
• an outer ring including an inner stepped interface on a radially inner surface thereof,
• N inner rings, wherein
• N is an integer greater than zero,
• at least one of the N inner rings is circumferentially segmented and includes an inner stepped interface and an outer stepped interface, and
• the outer stepped interface of a radially outer one of the N inner rings is configured to rest on and mate with the inner stepped interface of the outer ring, and
• a center portion including an outer stepped interface on a radially outer surface thereof that is configured to rest on and mate with the inner stepped interface of a radially inner one of the N inner rings,
• wherein
• the top plate and the gas distribution plate are dielectric windows,
• the top plate is disposed on the gas distribution plate, and
• a gap exists between the top plate and the gas distribution plate for passage of gas to a plurality of gas through holes in one or more of the N inner rings.