US Patent 9358702 Temperature management of aluminium nitride electrostatic chuck

An unseasoned substrate support assembly includes a ceramic body and a thermally conductive base bonded to a lower surface of the ceramic body. The substrate support assembly further includes an upper surface of the ceramic body having a first portion proximate to a center of the upper surface of the ceramic body and having a first roughness profile and a second portion distal from the center of the upper surface of the ceramic body and having a second roughness profile with a lower roughness than the first roughness profile, wherein areas of the first and second portions are based on radial distances from the center of the ceramic body.