Abstract: An electrostatic chuck and method for electrostatically clamping a working member such as a semiconductor wafer to the chuck. The elcetrostatic chuck includes at least one conductive electrode and an insulating layer for separating the conductive electrode from the working member. The insulating layer is composed of a composition containing pyrolytic boron nitiride (PBN) and a carbon dopant in an amount above 0 wt % and less than about 3 wt % such that its electrical resistivity is smaller than 10.sup.14 .OMEGA.-cm. A source of voltage is impressed across the conductive electrode to generate an electrostatic field which causes the working member to be clamped to the chuck.

Abstract: In accordance with the present invention a pyrolytic boron nitride compact having an electrical resistivity smaller than about 10.sup.14 .OMEGA.-cm is formed by the process of introducing a feed gas of gaseous boron halide and ammonia at a suitable ratio into a furnace heated to a temperature between 1600.degree. C. to 2200.degree. C. with the furnace containing a substrate of graphite to form a deposit of pyrolytic boron nitride upon said substrate, substantially simultaneously introducing a hydrocarbon gas into the furnace to form a codeposit of carbon in the crystal structure of the pyrolytic boron nitride deposit, controlling the mole fraction of said hydrocarbon gas to limit the concentration of carbon to less than about 3 wt % of the pyrolytic boron nitride composition.