NOVELTY - The assembly (238) has an inner heating element and an outer heating element that are embedded within the thermally conductive portion (224). The length and pattern of outer heating element are different from the length and pattern of the inner heating element. A cooling channel is embedded within the thermally conductive portion between the inner heating element and the outer heating element. The cooling channel includes branched passages that are different from each other.    USE - Substrate support assembly of large area substrate processing apparatus (claimed) of plasma enhanced chemical vapor deposition (PECVD) system. Uses include but are not limited to flexible display, organic LED (OLED) display, flexible organic LED (FOLED) display, polymer LED (PLED) display, LCD, organic thin film transistor, active matrix and passive matrix displays, top emission device, bottom emission device, solar cell, and solar panel.    ADVANTAGE - The substrate support assembly provides uniform heating and cooling across the surface of the substrate inside the process chamber. The power source is adjusted for heating elements and another power source is adjusted for cooling channels such that the temperature of the large area substrate is maintained efficiently. The shadow frame prevents deposition at the edges of the substrate that is not stuck to the substrate support assembly. The temperature of a substrate support surface of the substrate support assembly is adjusted and maintained during substrate processing and non-processing time in order to prevent the temperature spike or variation on the surface of the substrate. The entry port is coupled to a cleaning source to provide a cleaning agent into the process chamber to remove deposition by-products and films from the gas distribution plate assembly. The substrate support pins can be positioned near the perimeter of the substrate to facilitate the placement or removal of the substrate by a transfer robot or other transfer mechanism positioned exterior to the process chamber without interfering with the transfer robot.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for large area substrate processing apparatus.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of the process chamber.    Process chamber (202)    Gas source (204)    Walls (206)    Thermally conductive portion (224)    Substrate support assembly (238)