The present disclosure relates to a chemical vapor deposition system for processing large area substrates. The chemical vapor deposition system includes a chemical vapor deposition chamber comprising a chamber body having a plurality of sidewalls, a lid assembly, and a bottom. A substrate support extends upward from the bottom within the chamber body. A gas distribution plate is located within the lid assembly. One or more cleaning gas injector ports coupled to corresponding one or more inlets in the plurality of sidewalls. Each of the one or more cleaning gas injector ports has a substantially oval-shaped or circular-shaped cleaning gas nozzle configured to provide reactive species from a remote plasma source to clean an underside of the gas distribution plate.