Uniformity control for low flow process and chamber to chamber matching

摘要

Apparatus and methods for distributing gases into a processing chamber are disclosed. In one embodiment, the apparatus includes a gas distribution plate having a plurality of apertures disposed therethrough and a blocker plate having both a plurality of apertures disposed therethrough and a plurality of feed through passageways disposed therein. A first gas pathway delivers a first gas through the plurality of apertures in the blocker plate with sufficient pressure drop to more evenly distribute the gases prior to passing through the gas distribution plate. A bypass gas pathway delivers a second gas through the plurality of feed through passageways in the blocker plate and to areas around the blocker plate prior to the second gas passing through the gas distribution plate.