Gas distribution assemblies and processing chambers using same are described. The gas distribution assemblies comprise a cooling plate with a quartz puck, a plurality of reactive gas sectors and a plurality of purge gas sectors suspended therefrom. The reactive gas sectors and purge gas sectors having a coaxial gas inlet with inner tubes and outer tubes, the inner tubes and outer tubes in fluid communication with different gas or vacuum ports in the front faces of the sectors. The sectors may be suspended from the cooling plate by a plurality of suspension rods comprising a metal rod body with an enlarged lower end positioned within a quartz frame with a silicon washer around the enlarged lower end.