Patent attributes
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 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. A distance between the third surface and the first major surface is constant. A thickness of the second portion between the third and fourth surfaces varies such that the thickness at a circumferential end portion of the second portion which is less than that at a central portion of the second portion.