Abstract: A temperature-controlled showerhead assembly includes a stem with cooling gas passageways and at least one process gas delivery passageway, and a back plate thermally coupled to the stem. The showerhead also includes a face plate attached to the back plate and a convective heat transfer element (CHTE) thermally coupled to the back plate. The CHTE includes a sealing cup which isolates the CHTE heat transfer structures from the process environment. The CHTE includes an internal plenum including an inlet path for receiving a flow of cooling gas via at least a first one of the plurality of cooling gas passageways, and an outlet path for removing the flow of cooling gas from the CHTE via at least a second one of the plurality of cooling gas passageways. The received flow of cooling gas is thermally coupled with a surface of the back plate.