Embodiments described herein include processes and apparatuses relate to epitaxial deposition. A method for epitaxially depositing a material is provided and includes positioning a substrate on a substrate support surface of a susceptor within a process volume of a chamber body, where the process volume contains upper and lower chamber regions. The method includes flowing a process gas containing one or more chemical precursors from an upper gas inlet on a first side of the chamber body, across the substrate, and to an upper gas outlet on a second side of the chamber body, flowing a purge gas from a lower gas inlet on the first side of the chamber body, across the lower surface of the susceptor, and to a lower gas outlet on the second side of the chamber body, and maintaining a pressure of the lower chamber region greater than a pressure of the upper chamber region.