An electrostatic chuck (ESC) with a cooling base for plasma processing chambers, such as a plasma etch chamber. In embodiments, a plasma processing chuck includes a plurality of independent edge zones. In embodiments, the edge zones are segments spanning different azimuth angles of the chuck to permit independent edge temperature tuning, which may be used to compensate for other chamber related non-uniformities or incoming wafer non-uniformities. In embodiments, the chuck includes a center zone having a first heat transfer fluid supply and control loop, and a plurality of edge zones, together covering the remainder of the chuck area, and each having separate heat transfer fluid supply and control loops. In embodiments, the base includes a diffuser, which may have hundreds of small holes over the chuck area to provide a uniform distribution of heat transfer fluid.