An Electrostatic Chuck (ESC) in a chamber of a semiconductor manufacturing apparatus is presented for eliminating cooling-gas light-up. One wafer support includes a baseplate connected to a radiofrequency power source, a dielectric block, gas supply channels for cooling the wafer bottom, and first and second electrodes. The dielectric block is situated above the baseplate and supports the wafer when present. The first electrode is embedded in the top half of the dielectric block, where the top surface of the first electrode is substantially parallel to a top surface of the dielectric block, and the first electrode is connected to a DC power source. Further, the second electrode is embedded in a bottom half of the dielectric block, the second electrode being electrically connected to the first electrode, where the bottom surface of the second electrode is substantially parallel to a top surface of the baseplate.