High heat loss heater and electrostatic chuck for semiconductor processing

A substrate support assembly, comprising:

• an electrostatic chuck body defining a substrate support surface that defines a substrate seat, wherein:
• the electrostatic chuck body comprises a conductive material that is operable as a chuck without separate checking electrodes;
• the substrate support surface comprises a dielectric coating;
• a support stem coupled with the electrostatic chuck body, a top end of the support stem comprises a support bowl that is spaced apart from a bottom surface of the electrostatic chuck body, wherein a top end of the support stem comprises a support bowl that is disposed beneath the inner insulator and the outer insulator;
• a plurality of insulators disposed between the electrostatic chuck body and the support stem, the plurality of insulators comprising an inner insulator and an outer insulator;
• a cooling hub positioned below a base of the support stem and coupled with a cooling fluid source, wherein:
• the electrostatic chuck body defines at least one cooling channel that is in communication with the cooling fluid source;
• a lateral side of the cooling hub defines a cooling fluid inlet and a cooling fluid outlet;
• a heater embedded within the electrostatic chuck body;
• an AC power rod extending through the support stem and electrically coupled with the heater;
• and
• a plurality of voids formed within the electrostatic chuck body between the at least one cooling channel and the heater, wherein the plurality of voids comprises one or more first voids at a first depth within the electrostatic chuck body and one or more second voids at a second depth within the electrostatic chuck body, wherein the first depth is different than the second depth.