Embodiments provided herein generally relate to an apparatus for delivering gas to a semiconductor processing chamber. An upper quartz dome of an epitaxial semiconductor processing chamber has a plurality of holes formed therein and precursor gases are provided into a processing volume of the chamber through the holes of the upper dome. Gas delivery tubes extend from the holes in the dome to a flange plate where the tubes are coupled to gas delivery lines. The gas delivery apparatus enables gases to be delivered to the processing volume above a substrate through the quartz upper dome.