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, for example, 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. The electrostatic chuck may be bonded to heat sinks coated with anti-arc dielectrics. The
heat sink can also be used as an RF
electrode. The
heat sink may have provisions for coolants and gas channels to feed a cooling gas to the backside of a
wafer. The
heat sink may have feed thrus to power the segmented electrodes in the electrostatic chuck. The passages for the feed thrus, gas feed holes and lift pins may be lined with ceramics or polymers to prevent any
discharge to the heat sink. The electrostatic chuck is for clamping work substrates like Si, GaAs, SiO2, etc. used in
semiconductor tools.