Electrostatic chuck

Abstract

Disclosed is an electrostatic chuck comprising a ceramic dielectric layer having a surface for placing thereon a work that is to be held, and an electrode provided on a surface opposite to the surface of the ceramic dielectric layer for placing the work thereon, wherein: the placing surface of the ceramic dielectric layer is sectionalized into an outer peripheral region and a central region by gas injection grooves extending in a circumferential manner; the surface roughness Ra(o) of the outer peripheral region of the placing surface and the surface roughness Ra(i) ot the central region satisfy the following conditions: 0.6≦Ra(i)≦1.5 μm Ra(o)≦0.7 μm Ra(i)≧Ra(o) and the outer peripheral region of the placing surface is higher than the inner peripheral region by not less than 0.6 μm. The electrostatic chuck holds the substrate with a large adsorptive force, maintains evenness in the heat distribution of the substrate, enables the substrate to be quickly separated away from the chuck, and permits the gas to leak little.

Dependencies are inferred from the claim text.