US Patent 7667944 Polyceramic e-chuck

The present invention discloses an electrostatic chuck for clamping work substrates, said chuck comprising three layers, where the dielectric constant of included non-conductive layers is selected to provide overall lower capacitance to the chuck. In the chuck assembly of the present invention, the top dielectric layer that is in contact with a substrate, such as, a wafer, has a dielectric constant that is preferably greater than about 5, with a resistivity that is preferably greater than about 1E6 ohm.m, whereas the bottom dielectric layer has a dielectric constant that is preferably less than about 5 and a resistivity that is preferably greater than about 1E10 ohm.m. The intermediate layer preferably has a conductive layer where the resistivity is less than about 1 ohm.m.