Tapered post, showerhead design to improve mixing on dual plenum showerheads

摘要

This invention provides a showerhead and method for allowing reaction gases to immediately mix upon release from gas outlets and minimize deposits of unwanted contaminants on the tip of a gas outlet and faceplate of the showerhead. A post having a central opening extends into the faceplate for emitting a first gas and is directly and circumferentially surrounded by an annular opening for emitting a second gas. The post may be recessed from, flush with or extend a distance past a frontal surface of the faceplate. A plurality of apertures, for emitting the second gas, may circumferentially surround the annular opening. The annular opening releases the second gas at a pressure and velocity sufficient to intermix with first gas released from the post while simultaneously forcing any unreacted gas and gaseous mixtures away from the tip of the post and frontal surface of the faceplate, thereby avoiding depositing contaminants thereon.