Embodiments of electrostatic chucks are provided herein. In some embodiments, an electrostatic chuck may include a body having a notched upper peripheral edge, defined by a first surface perpendicular to a body sidewall and a stepped second surface disposed between the first surface and a body upper surface, and a plurality of holes disposed through the body along the first surface; a plurality of fasteners disposed through the plurality of holes to couple the body to a base disposed beneath the body; a dielectric member disposed above the body upper surface to electrostatically retain a substrate; an insulator ring disposed about the body within the notched upper peripheral edge and having a stepped inner sidewall that mates with the stepped second surface to define a non-linear interface therebetween; and an edge ring disposed over the insulator ring, the non-linear interface limiting arcing between the edge ring and the fastener.