Embodiments of the present invention generally relate to methods and apparatus for chemical vapor deposition (CVD) on a substrate, and, in particular, to a process chamber and components for use in metal organic chemical vapor deposition. The apparatus comprises a chamber body defining a process volume. A showerhead in a first plane defines a top portion of the process volume. A carrier plate extends across the process volume in a second plane forming an upper process volume between the showerhead and the susceptor plate. A transparent material in a third plane defines a bottom portion of the process volume forming a lower process volume between the carrier plate and the transparent material. A plurality of lamps forms one or more zones located below the transparent material. The apparatus provides uniform precursor flow and mixing while maintaining a uniform temperature over larger substrates thus yielding a corresponding increase in throughput.