US Patent 11557465 Electrostatic chuck

According to one embodiment, an electrostatic chuck includes a ceramic dielectric substrate, a base plate, and first and second electrode layers. The ceramic dielectric substrate includes first and second major surfaces. The first and second electrode layers are provided inside the ceramic dielectric substrate. The second electrode layer is provided between the first electrode layer and the first major surface. The first electrode layer includes first and second portions. The first portion is positioned more centrally of the ceramic dielectric substrate than is the second portion. The first portion includes first and second surfaces. The second portion includes third and fourth surfaces. The third surface is positioned between the first surface and the second electrode layer. An electrical resistance of the first surface is less than an average electrical resistance of the first portion.