An apparatus and methods for an upgraded CVD system providing a remote plasma for efficiently cleaning a chamber, according to a specific embodiment. Etching or depositing a layer onto a substrate also may be achieved using the upgraded CVD system of the present invention. In a specific embodiment, the present invention provides apparatus for an easily removable, conveniently handled, and relatively inexpensive, robust microwave plasma source as a retrofit for or a removable addition to existing CVD apparatus. The present invention provides an improved CVD apparatus or retrofit of existing CVD apparatus capable of producing a remote plasma for efficiently cleaning the chamber.